Radiation Injuries

Purpose: Normal tissue complication probability ͑NTCP͒ of the rectum, bladder, urethra, and femoral heads following several techniques for radiation treatment of prostate cancer were evaluated applying the relative seriality and Lyman models. Methods: Model parameters from literature were used in this evaluation. The treatment techniques included external ͑standard fractionated, hypofractionated, and dose-escalated͒ three-dimensional conformal radiotherapy ͑3D-CRT͒, low-dose-rate ͑LDR͒ brachytherapy ͑I-125 seeds͒, and highdose-rate ͑HDR͒ brachytherapy ͑Ir-192 source͒. Dose-volume histograms ͑DVHs͒ of the rectum, bladder, and urethra retrieved from corresponding treatment planning systems were converted to biological effective dose-based and equivalent dose-based DVHs, respectively, in order to account for differences in radiation treatment modality and fractionation schedule. Results: Results indicated that with hypofractionated 3D-CRT ͑20 fractions of 2.75 Gy/fraction delivered five times/week to total dose of 55 Gy͒, NTCP of the rectum, bladder, and urethra were less than those for standard fractionated 3D-CRT using a four-field technique ͑32 fractions of 2 Gy/fraction delivered five times/week to total dose of 64 Gy͒ and dose-escalated 3D-CRT. Rectal and bladder NTCPs ͑5.2% and 6.6%, respectively͒ following the dose-escalated four-field 3D-CRT ͑2 Gy/fraction to total dose of 74 Gy͒ were the highest among analyzed treatment techniques. The average NTCP for the rectum and urethra were 0.6% and 24.7% for LDR-BT and 0.5% and 11.2% for HDR-BT. Conclusions: Although brachytherapy techniques resulted in delivering larger equivalent doses to normal tissues, the corresponding NTCPs were lower than those of external beam techniques other than the urethra because of much smaller volumes irradiated to higher doses. Among analyzed normal tissues, the femoral heads were found to have the lowest probability of complications as most of their volume was irradiated to lower equivalent doses compared to other tissues.

Background and purpose: Investigation of the use of TomoTherapy and TomoDirect versus conventional radiotherapy for the treatment of post-operative breast carcinoma. This study concentrates on the evaluation of the planning protocol for the TomoTherapy and TomoDirect TPS, dose verification and the implementation of in vivo dosimetry. Materials and methods: Eight patients with different breast cancer indications (left/right tumor, axillary nodes involvement (N+)/no nodes (N0), tumorectomy/mastectomy) were enrolled. TomoTherapy, Tomo-Direct and conventional plans were generated for prone and supine positions leading to six or seven plans per patient. Dose prescription was 42 Gy in 15 fractions over 3 weeks. Dose verification of a TomoTherapy plan is performed using TLDs and EDR2 film inside a home-made wax breast phantom fixed on a randoalderson phantom. In vivo dosimetry was performed with TLDs. Results: It is possible to create clinically acceptable plans with TomoTherapy and TomoDirect. TLD calibration protocol with a water equivalent phantom is accurate. TLD verification with the phantom shows measured over calculated ratios within 2.2% (PTV). An overresponse of the TLDs was observed in the low dose regions (<0.1 Gy). The film measurements show good agreement for high and low dose regions inside the phantom. A sharp gradient can be created to the thoracic wall. In vivo dosimetry with TLDs was clinically feasible. Conclusions: The TomoTherapy and TomoDirect modalities can deliver dose distributions which the radiotherapist judges to be equal to or better than conventional treatment of breast carcinoma according to the organ to be protected.

Developing a mass-casualty medical response to the detonation of an improvised nuclear device (IND) or large radiological dispersal device (RDD) requires unique advanced planning due to the potential magnitude of the event, lack of warning, and radiation hazards. In order for medical care and resources to be collocated and matched to the requirements, a [US] Federal interagency medical response-planning group has developed a conceptual approach for responding to such nuclear and radiological incidents. The &quot;RTR&quot; system (comprising Radiation-specific TRiage, TReatment, TRansport sites) is designed to support medical care following a nuclear incident. Its purpose is to characterize, organize, and efficiently deploy appropriate materiel and personnel assets as close as physically possible to various categories of victims while preserving the safety of responders. The RTR system is not a medical triage system for individual patients. After an incident is characterized and safe...

The study is designed to determine the therapeutic effect of caffeic acid phenethyl ester (CAPE) in minimizing radiation-induced injuries in rats. Rats were exposed to 7 Gy gamma radiation, 30 min later rats were injected with CAPE (10 mmol/kg body, i.p.) for 7 consecutive days. Rats were sacrificed at 8 and 15 days after starting the experiment. Gamma-irradiation induced significant increase in malondialdehyde (MDA) level and xanthine oxidase (XO) and adenosine deaminase (ADA) activities, and significant decrease in total nitrate/nitrite (NO(x)) level and glutathione peroxidise (GPx), superoxide dismutase (SOD) and catalase activities in heart tissue and augmented lipid fractions levels and activities of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and aspartate transaminase (AST) in serum. Irradiated rats early treated with CAPE showed significant decrease in MDA, XO and ADA and significant increase in NO(x) and SOD in heart tissue and in serum enzymes compared with irradiated group. Serum lipid profiles and cardiac enzymes were restored. Conclusion: CAPE could exhibits curable effects on gamma irradiation-induced cardiac-oxidative impairment in rats.

Background and purpose: Some types of radiation therapy have been associated with an increased risk of cardiac mortality and morbidity in patients with early-stage breast cancer. A relationship has been observed between cardiac radiation dose-volume and the level of excess risk of cardiac mortality. However, relatively few data are available on the morbidity from myocardial infarction associated with adjuvant radiotherapy.

Radiation proctitis is a well-known complication of abdominal and pelvic radiation. Conventional medical and surgical treatment often is disappointing. 5-Aminosalicylic Acid (5-ASA) is the active component in sulfasalazine and is effective in the treatment of distal ulcerative colitis. Four patients with radiation proctitis were treated with 4 g 5-ASA by enema nightly for two to six months. Patients were seen monthly, interviewed, and a sigmoidoscopic exam performed. No change was seen in the degree of mucosal inflammation on foUow-up sigmoidoscopic exams. Three patients noted no change in their symptoms of bleeding, pain, or tenesmus. One patient noted initial improvement, but this was not sustained. 5-ASA enemas do not appear to be effective in the treatment of radiation proctitis.

A highly individualized stereotactic body radiotherapy (SBRT) strategy was developed to allow a wide spectrum of patients with liver cancer to be treated. This phase I/II study encompasses individualization of immobilization, radiation planning, PTV margin determination, image guidance strategy and prescription dose. Active breathing control breath hold is used to immobilize the liver when feasible. Image guidance strategies include orthogonal MV images and orthogonal kV fluoroscopy using the diaphragm for a surrogate for the liver, and kV cone beam CT using the liver or tumour for guidance. The prescription dose is individualized to maintain the same estimated risk of radiation-induced liver disease (RILD), based on a normal tissue complication probability (NTCP) model, with a maximum permitted dose of 60 Gy in 6 fractions. Since August 2003, 79 patients with hepatocellular carcinoma (33), intrahepatic cholangiocarcinoma (12) and liver metastases (34) were treated. The median tumour volume was 293 cm3 (2.9-3 088 cm3). The median prescribed dose was 36.6 Gy (24.0 Gy-57.0 Gy) in 6 fractions. The median effective liver volume irradiated was 45% (9-80%). Sixty percent of patients were treated with breath hold to immobilize their liver. Intra-fraction reproducibility (sigma) of the liver with repeat breath holds was excellent (1.5 mm); however inter-fraction reproducibility (sigma) was worse (3.4 mm). Image guidance reduced the residual systematic and random setup errors significantly.

The common consequences of radiotherapy (RT) to the head and neck are oral mucositis, xerostomia, and severe pain. The aim of this study was to verify how laser phototherapy (LPT) used for oral mucositis could influence xerostomia symptoms and hyposalivation of patients undergiong RT. Patients were divided into two groups: 12 individuals receiving three laser irradiations per week (G1) and 10 patients receiving one laser irradiation per week (G2). A diode laser (660 nm, 6 J=cm 2 , 0.24 J, 40 mW) was used until completely healing of the lesions or the end of the RT. At the first and last laser sessions, whole resting and stimulated saliva were collected, and questionnaires were administered. According to Wilcoxon and Student statistical test, xerostomia for G1 was lower than for G2 ( p < 0.05), and salivary flow rate was no different before and after RT, except for stimulated collection of G2, which was lower ( p < 0.05). Our results suggest that LPT can be beneficial as an auxiliary therapy for hypofunction of salivary glands.

Background: The authors report the treatment of three female patients with severe actinic rectitis, with stenosis or perforation, submitted to anterior proctosigmoidectomy and transanal coloanal anastomosis. Methods: In all cases surgery consisted of total proctosigmoidectomy, mucosectomy of the anal canal, lowering of the left colon through the pelvis and transanal anastomosis performed manually at the level of the pectineal line using separate absorbable sutures. A protective intestinal shunt was performed in all cases. Results: The three patients did not present transoperative or immediate postoperative complications, but the first patient developed deep venous thrombosis of the leg that was submitted to successful clinical treatment. The intestinal shunts were later closed in all three cases. Sphincter function was considered very good in the first case and regular in the remaining two. Conclusion: The surgical technique utilized was considered to be adequate for the cases reported and is the first option for the maintenance of transit in patients with severe actinic rectitis since the anastomosis is performed using non-irradiated colon with the pectineal line, practically outside the pelvis. ROSSI, 8.M.; NAKAGAWA, W.T.; FERNANDES, J.A.P.; LOPES, A; PAEGLE, L.D. -Treatment of severe actinic rectitis Sao Paulo Medical Journal/RPM 116(1): 1629-1633, 1998 sao Paulo Medical Journal/RPM 116(1): 1629-1633, 1998 ROSSI, 8.M.; NAKAGAWA, W.T.; FERNANDES, J.A.P.; LOPES, A; PAEGLE, L.D. -Treatment of severe actinic rectitis ROSSI, 8.M.; NAKAGAWA, W.T.; FERNANDES, J.A.P.; LOPES, A; PAEGLE, L.D. -Treatment of severe actinic rectitis Sao

Purpose: To assess the incidence of middle ear (ME) pathology in patients treated with radiotherapy (RT) for skull base tumors. Methods and Materials: A retrospective analysis of 61 patients treated with RT between 2003 and 2008 for skull base tumors was conducted. Clinical outcomes and demographics were reviewed. Dose-volume histogram analysis was performed on the eustachian canal (EC), ME, mastoid air cells, vestibular apparatus, cochlea, internal auditory canal, lateral and posterior nasopharynx, and temporal lobes to relate doses to symptoms and radiographic change. Otomastoid opacification was rated 0 (none), 1 (mild), 2 (moderate), and 3 (severe) by a neuroradiologist blinded to clinical outcomes and doses. Results: The median prescribed dose was 50.4 Gy (range, 14-74 Gy). The ME mean dose was 14 Gy and 34 Gy for Grade 0-1 and 2-3 opacification, respectively (p < 0.0001). The mean mastoid dose was 10 Gy and 26 Gy for Grade 0-1 and 2-3, respectively (p < 0.0001). The mean EC dose was 17 Gy and 32 Gy for Grade 0-1 and 2-3, respectively (p = 0.0001). Otomastoid opacification resolved in 17 of 40 patients (42.5%), at a mean of 17 months after RT (range, 2-45 months). Otomastoid opacification persisted in 23 of 40 patients (57.5%), with a mean follow-up of 23 months (range, 2-55 months). Multivariate analysis showed that mastoid dose >30 Gy (odds ratio = 28.0, p < 0.001) and posterior nasopharynx dose of >30 Gy (odds ratio = 4.9, p = 0.009) were associated with Grade 2-3 effusions, whereas other factors including dose to EC and ME were not significant. Conclusions: A mean RT dose >30 Gy to the mastoid air cells or posterior nasopharynx is associated with increased risk of moderate to severe otomastoid opacification, which persisted in more than half of patients at 2-year followup. Ó 2011 Elsevier Inc.

Goal of work To examine the frequency and types of complementary and alternative medicine use in patients undergoing radiotherapy and to analyze the effects these therapies have on the toxicities of radiotherapy. Materials and methods A total of 210 consecutive cancer patients undergoing radiation therapy were included. After radiation therapy, each patient completed a standard questionnaire, and the association between radiation toxicity and complementary and alternative medicine use was analyzed. Main results Among the study population, 44.3% of patients reported using at least one form of complementary and alternative medicine during radiotherapy. The most commonly chosen complementary and alternative medicine was stinging nettle. Complementary and alternative medicine use decreased lower gastrointestinal (F=3.26, P=.009) and genitourinary toxicities (F=2.38, P=.043), while it increased laryngeal toxicity (F=2.63, P=.028). A significant correlation between the type of complementary and alternative medicine used and the degree of these toxicities was not demonstrated. Conclusions Use of complementary and alternative medicine among cancer patients during radiation therapy may affect the degree of radiation toxicity. Further randomized controlled clinical trials are needed to determine the benefits and risks of complementary and alternative medicine use during radiation therapy.

Background: The purpose of this study was to evaluate the efficacy of oral glutamine in the prevention of acute radiation-induced esophagitis (ARIE) and weight loss in lung carcinoma patients, and to determine the clinical/dosimetric predictors of ARIE. Patients and methods: Data from 41 patients with stage III lung carcinoma treated with thoracic irradiation were retrospectively analyzed. Twenty-two patients (53.6%) received prophylactic powdered glutamine in doses of 10 g/8 h. Prescribed radiation dose to planning target volume was 60 Gy, in 30 fractions, 5 days/week. The primary endpoint included the ARIE incidence and its correlation with clinical/dosimetric factors relative to treatment with glutamine. Results: Glutamine was well tolerated. Grade 2 or 3 ARIE occurred in 20 (48.8%) of 41 patients: seven in the glutamine-supplemented group, and 13 in the glutamine-free group (p = 0.002). All seven patients with grade 3 esophagitis were in the glutamine-free group (36.8% vs. 0%). Glutamine supplementation appeared to significantly delay ARIE onset for six days (22 days vs. 16 days; p = 0.002). Glutamine-supplemented patients demonstrated a lower incidence of grade 2 or 3 ARIE (27.2%), and gained weight during radiotherapy (p = 0.04). V55 was the only dosimetric parameter that correlated with the severity of ARIE in glutamine-free patients: a V55 of <35% had a 31% risk of ARIE grade 2 or 3, and the risk increased to 76% with a V55 of ≥35% (p = 0.01). Conclusion: This schedule and dosage of glutamine may be beneficial in the prevention of ARIE and weight loss in lung cancer patients undergoing thoracic irradiation.

This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/ cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the reninangiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower renal retention may be developed. Furthermore, knowledge on kidney protection from radiolabelled somatostatin analogues may be expanded to other peptides.

Purpose: Anterior callosotomy is a surgical option for the treatment of generalized tonic or atonic seizures associated with drop attacks. Besides open surgery, a radiosurgical callosal disconnection using the gamma knife (GK) also can be performed, but reliable data about tolerability and efficacy are sparse.

The controversy over the Smithsonian Enola Gay exhibition implies that it is still taboo to question the United States&amp;#x27; use of the atomic bomb. Veterans&amp;#x27; groups and conservatives succeeded in using the exhibit to justify and glorify the use of the atomic bomb. Historical facts, ...

When treatment intent is to include breast and internal mammary lymph nodes (IMNs) in the clinical target volume (CTV), a significant volume of the heart may receive radiation, which may result in late morbidity. The value of conformal intensity-modulated radiation therapy (IMRT) to avoid heart dose was studied.Breast, IMNs, and normal tissues were contoured for 30 consecutive patients previously treated with RT after lumpectomy for left-sided breast cancer. Eleven-beam, conformal, inverse-planned IMRT plans were developed and compared with best standard plans. Conformity Index (CI), Homogeneity Index (HI), and doses to normal tissues were compared.Intensity-modulated RT significantly improved (two-sided paired t test) HI (0.95 vs. 0.74), CI (0.91 vs. 0.48), volume of the heart receiving more than 30 Gy (V30-heart) (1.7% vs. 12.5%), and volume of lung receiving more than 20-Gy (V20-left lung) (17.1% vs. 26.6%), all p < 0.001. The mean Healthy Tissue Volume (HTV = CT set – PTV) dose was similar between IMRT and best standard plans (6.0 and 6.9 Gy, respectively), but IMRT increased the volume of normal tissues receiving low-dose RT: V5-right lung (13.7% vs. 2.0%), V5-right breast (29.2% vs. 7.9%), and V5-HTV (31.7% vs. 23.6%), all p < 0.001. IMRT plans were generated in less than 60 min and treatment delivered in approximately 20 min, suggesting that this technique is clinically applicable.IMRT significantly improved conformity and homogeneity for plans when the breast + IMNs were in the CTV. Heart and lung volume receiving high doses were decreased, but more healthy tissue received low doses. A simple algorithm based on amount of heart included in the standard plan showed limited ability to predict the benefit from IMRT.

The volume, distribution, and mobility of opacified pelvic small bowel (PSB) were determined by fluoroscopy and orthogonal radiqgraphs in 150 consecutive patients undergoing pelvic irradiation. Various techniques including uteropexy, omenlal transposition, bladder distention, inclining the patient, and anterior abdominal wall compression in the supine and prone treatment position were studied for their effect on the volume and location of small bowel within the pelvis. Abdominal wall compression in the prone position combined with bladder distention was selected for further investigation because of its simplicity, reproducibility, patient comfort, and ability to displace the small bowel. Factors correlating with the volume of pelvic small bowel (PSB) included prior pelvic surgery, pelvic irradiation (XRT), and body mass index. After pelvic surgery, especially following abdominoperineal resection (APR), there was a greater volume of PSB which was also less mobile. The severity of acute gastrointestinal effects positively correlated with the volume of irradiated small bowel. Overall, 67% of patients experienced little or no diarrhea, 30% developed m,ild diarrhea, and no patient required treatment interruption. Late gastrointestinal effects correlated with the prior pelvic surgery and with the volume of small bowel receiving greater than 45 Gy. Small bowel obstruction was not observed in 75 patients who had no previous pelvic surgery. However, following pelvic surgery excluding APR, 2150 patients and following APR, 3125 patients developed small bowel obstruction.

Advances in cancer therapy have resulted in significant improvement in long-term survival for many types of cancer but have also resulted in untoward side effects associated with treatment. One such complication that has become increasingly recognized is the development of cardiomyopathy and heart failure. Whether a previously healthy person from a cardiovascular perspective develops cancer therapy–related cardiac dysfunction or a high-risk cardiovascular patient requires cancer therapy, the team of oncologists and cardiologists must be better equipped with an evidence-based approach to care for these patients across the spectrum. Although the toxicities associated with various cancer therapies are well recognized, limitations to our understanding of the appropriate course of action remain. In this first of a 2-part review, we discuss the epidemiologic, pathophysiologic, risk factors, and imaging aspects of cancer therapy–related cardiac dysfunction and heart failure. In a subsequen...

Treatment with pelvic external beam radiotherapy with brachytherapy (EBRT/BT) for gynecological cancers may cause sexual dysfunction because of vaginal shortening and tightening. Regular vaginal dilator use is thought to reduce vaginal shortening and/or tightening, but compliance is poor. Aims. This study identified determinants of patients' adherence with dilator use after EBRT/BT. Methods. Semi-structured interviews were conducted with 30 women, aged 32-67 years, treated with EBRT/BT for gynecological cancers at two university medical centers in the past 36 months. Transcriptions were coded and analyzed with N-Vivo software. Main Outcome Measures. Determinants of dilator use were clustered based on the Health Action Process Approach, which describes (i) motivation processes that lead to a behavioral intention and (ii) volition processes that lead to the initiation or maintenance of actual behavior. Results. Almost all women attempted to perform long-term regular vaginal dilator use. Intended dilator use was determined by the expectation that it would prevent the development of vaginal adhesions and stenosis. Planning dilator use and making it part of a routine, using it under the shower, using lubricants, a smaller dilator size, or vibrators helped women. Others reported a lack of time or privacy, forgetting, or feeling tired. Women self-regulated dilator use by rotating the dilator and timing dilator use. Influencing factors were negative emotions regarding dilator use or its hard plastic design, (being anxious for) pain or blood loss, and an association with EBRT/BT. Some women mentioned a lack of instrumental support, for example, lubricants. Others received reassurance through informational support or were supported socially. Conclusion. Motivation and volition processes that determined dilator use were identified and used in the development of a sexual rehabilitation intervention. It is important to provide sufficient patient information and support, and enlarge patients' perceived self-efficacy. Bakker RM, Vermeer WM, Creutzberg CL, Mens JWM, Nout RA, and ter Kuile MM. Qualitative accounts of patients' determinants of vaginal dilator use after pelvic radiotherapy. J Sex Med 2015;12:764-773.

A simple to use method was installed for the measurement of wounds contaminated with plutonium and americium by using a semiconductor detector. This technique does not explicitly require the knowledge of the detector efficiency but uses a plant 24tAm calibration source. A computer programme has also been developed for the quantification of the contamination according to the shape and the depth of the contaminant in the wound.

To compare the cost-effectiveness of treating prostate cancer patients with intensity-modulated radiation therapy and a spacer (IMRT+S) versus IMRT-only without a spacer (IMRT-O). A decision-analytic Markov model was constructed to examine the effect of late rectal toxicity and compare the costs and quality-adjusted Life Years (QALYs) of IMRT-O and IMRT+S. The main assumption of this modeling study was that disease progression, genito-urinary toxicity and survival were equal for both comparators. For all patients, IMRT+S revealed a lower toxicity than IMRT-O. Treatment follow-up and toxicity costs for IMRT-O and IMRT+S amounted to €1604 and €1444, respectively, thus saving €160 on the complication costs at an extra charge of €1700 for the spacer in IMRT+S. The QALYs yielded for IMRT-O and IMRT+S were 3.542 and 3.570, respectively. This results in an incremental cost-effectiveness ratio (ICER) of €55,880 per QALY gained. For a ceiling ratio of €80,000, IMRT+S had a 77% probability of...

Choanal stenosis has recently been recognized as a late complication of radiation therapy for nasopharyngeal carcinoma. The management of velopharyngeal stenosis is challenging with high risk of restenosis. We report a case of velopharyngeal stenosis post-radiotherapy and illustrated the use of mitomycin-C to prevent restenosis. Mitomycin-C application has being shown useful adjunct to surgical technique in managing nasopharyngeal stenosis for surgeons. #

In 1997, the National Cancer Institute (NCI) led an effort to revise and expand the Common Toxicity Criteria (CTC) with the goal of integrating systemic agent, radiation, and surgical criteria into a comprehensive and standardized system. Representatives from the Radiation Therapy Oncology Group (RTOG) participated in this process in an effort to improve acute radiation related criteria and to achieve better clarity and consistency among modalities. CTC v. 2.0 replaces the previous NCI CTC and the RTOG Acute Radiation Morbidity Scoring Criteria and includes more than 260 individual adverse events with more than 100 of these applicable to acute radiation effects. One of the advantages of the revised criteria for radiation oncology is the opportunity to grade acute radiation effects not adequately captured under the previous RTOG system. A pilot study conducted by the RTOG indicated the new criteria are indeed more comprehensive and were preferred by research associates. CTC v. 2.0 represents an improvement in the evaluation and grading of acute toxicity for all modalities.

The capability to make diagnostic assessments of radiation exposure is needed to support triage of radiation casualties and medical treatment decisions in military operations. At the International Conference on Low-Level Radiation Injury and Medical Countermeasures session on biodosimetry in the military, participants reviewed the field of biomarkers, covering a wide range of biological endpoints. Participants evaluated early changes associated with exposure to ionizing radiation, including chromosomal and DNA damage, gene expression and associated proteins, and DNA mutations. The use and development of advanced monitoring and diagnostic technologies compatible with military operations was emphasized. Conventional radiation bioassays require a substantial amount of time between when the sample is taken and when the data can be provided for decision making. These &quot;reach back&quot; bioassays are evaluated in laboratories that are not in the field; these laboratories routinely mea...

Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, &quot;radiation caries&quot; is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration. Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines. No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for othe...

We assessed dosimetric differences in pancreatic cancer radiotherapy via helical intensity-modulated radiotherapy (HIMRT), linac-based IMRT, and 3D-conformal radiation therapy (3D-CRT) with regard to successful plan acceptance and dose to critical organs. Dosimetric analysis was performed in 16 pancreatic cases that were planned to 54 Gy; both post-pancreaticoduodenectomy (n ‫؍‬ 8) and unresected (n ‫؍‬ 8) cases were compared. Without volume modification, plans met constraints 75% of the time with HIMRT and IMRT and 13% with 3D-CRT. There was no statistically significantly improvement with HIMRT over conventional IMRT in reducing liver V35, stomach V45, or bowel V45. HIMRT offers improved planning target volume (PTV) dose homogeneity compared with IMRT, averaging a lower maximum dose and higher volume receiving the prescription dose (D100). HIMRT showed an increased mean dose over IMRT to bowel and liver. Both HIMRT and IMRT offer a statistically significant improvement over 3D-CRT in lowering dose to liver, stomach, and bowel. The results were similar for both unresected and resected patients. In pancreatic cancer, HIMRT offers improved dose homogeneity over conventional IMRT and several significant benefits to 3D-CRT. Factors to consider before incorporating IMRT into pancreatic cancer therapy are respiratory motion, dose inhomogeneity, and mean dose.

Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose-area-product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4¡121.0 Gycm 2 ) than single-plane imaging (133.6¡92.8 Gycm 2 , p,0.0001). The difference was independent of case type (primary or elective) (p50.862), vascular territory (p50.519) and operator experience (p50.903). No significant difference was found in contrast load between biplane (166.8¡62.9 ml) and single-plane imaging (176.8¡66.0 ml) (p50.302). This non-significant difference was independent of case type (p50.551), vascular territory (p50.308) and operator experience (p50.304). Procedures performed with biplane imaging were significantly longer (55.3¡27.8 min) than those with single-plane (48.9¡24.2 min, p50.010) and, similarly, were not dependent on case type (p50.226), vascular territory (p50.642) or operator experience (p50.094). Biplane imaging resulted in a greater radiation dose and a longer procedural time and delivered a non-significant reduction in contrast load than single-plane imaging. These findings did not support the commonly perceived advantages of using biplane imaging in single-vessel coronary interventional procedures.

When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior ''low neck'' field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction. Ó 2007 Elsevier Inc.

To improve the quality of liver stereotactic body radiation therapy (SBRT) treatments, a novel 4π framework was developed with accompanying algorithms to optimize non-coplanar beam orientations and fluences. The dose optimization is performed on a patient-specific deliverable beam geometry solution space, parameterized with patient and linear accelerator gantry orientations. Beams causing collision between the gantry and the couch or patient were eliminated by simulating all beam orientations using a precise computer assisted design model of the linear accelerator and a human subject. Integrated beam orientation and fluence map optimizations were performed on remaining beams using a greedy column generation method. Testing of the new method was performed on 10 liver SBRT cases previously treated with 50 to 60 Gy in 5 fractions using volumetric modulated arc therapy (VMAT). For each patient, both 14 and 22 non-coplanar fields were selected and optimized to meet the objective of ≥95% of the planning target volume (PTV) covered by 100% of the prescription dose. Doses to organs at risk, normal liver volumes receiving &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;15 Gy, integral dose, and 50% dose spillage volumes were compared against the delivered clinical VMAT plans. Compared with the VMAT plans, the 4π plans yielded reduced 50% dose spillage volume and integral dose by 22% (range 10%-40%) and 19% (range 13%-26%), respectively. The mean normal liver volume receiving &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;15 Gy was increased by 51 cc (range 21-107 cc) with a 31% reduction of the mean normal liver dose. Mean doses to the left kidney and right kidney and maximum doses to the stomach and spinal cord were on average reduced by 70%, 51%, 67%, and 64% (P≤.05). This novel 4π non-coplanar radiation delivery technique significantly improved dose gradient, reduced high dose spillage, and improved organ at risk sparing compared with state of the art VMAT plans.

Relato de Caso | Case RepoRt INTRODUCTION Solar retinopathy, also known as photomaculopathy, eclipse re tinopathy and foveomacular retinitis, is retinal damage resulting from direct or indirect solar observations during a solar eclipse or on a normal day (1). Light can damage the retina via mechanical, thermal or photochemical means, either alone or in combination. Photoche mical damage (actinic) occurs during prolonged low irradiance ex posure that lasts more than 10 seconds (2). Retinal impairment can be mild or severe (3). Young people are most vulnerable to damage (3). The earliest definitive report was in the eighteenth century and involved five cases of maculopathy due to exposure to the sun, fire or snow (4). The objective of the present study is to report the case of a patient suffering from solar retinopathy and to discuss its disease etiology and prevention. CASE REPORT A.M.R.B., 38, female, white, married, complained of metamor phopsia in the left eye for five months. The patient denied using me dication regularly, having any systemic diseases or having a history of abnormal solar exposure. Upon physical examination, the patient had 20/20 visual acuity in both eyes, including 4.75 sph. 0.50 cyl. at 20° in the right eye (RE) and 5.25 sph. in the left eye (LE). Biomicroscopy showed no changes

The safety of tissue allografts has come under increased scrutiny due to recent reports of allograft-associated bacterial and viral infections in tissue recipients. We report that 50 kGy of gamma irradiation, nearly three times the dose currently used, is an effective pathogen inactivation method when used under optimized conditions that minimize damage to the tissue. Cancellous bone dowels treated with a radioprotectant solution and 50 kGy of optimized irradiation had an ultimate compressive strength and modulus of elasticity equal to conventionally irradiated (18 kGy) and non-irradiated control bone grafts. We subjected bone dowels treated with this pathogen inactivation method to an in vitro cytotoxicity test using three different mammalian cell lines and concluded that the treated grafts were not cytotoxic. The log reduction of nine pathogens spiked into radioprotectant-treated bone irradiated to 50 kGy was also tested. We achieved 4.9 logs of inactivation of a model virus for HIV and hepatitis C and 5 logs inactivation of a model virus for human parvovirus B-19. Complete inactivation (6.0-9.2 logs) of seven clinically relevant microorganisms was demonstrated. The results show that a combination of radioprotectants and optimized, high-dose gamma irradiation is a viable method for producing safer cancellous bone grafts that have the mechanical strength of existing grafts. r

Background. Both loss of the secretory function and impairment of the excretion may play a role in radiationinduced injury of the major salivary glands after radiotherapy for head and neck malignancies. Therefore, quantitative ""Tc-pertechnetate (""' Tc) salivary scintigraphy to assess trapping, secretion, and excretion, was used to analyze irradiation-induced changes in relation to the radiation dose and the time interval after radiotherapy.

Digital radiography systems based on flat-panel detectors have been introduced into clinical practice in the past few years. The high detective quantum efficiency of these detectors allows the radiation dose to be reduced while maintaining image quality, an issue particularly significant for pediatric radiography. Another important aspect for dose optimization and monitoring is the integration of the detector into a computer-controlled x-ray examination system. This enables full control and complete reporting of all dose-relevant exposure parameters, including the determination of the exposure indicator and the patient dose (kerma-area product). In this paper the implementation of these principles in the Philips Digital Diagnost DR system is described and their relevance for pediatric applications is discussed.

Purpose: To retrospectively report the outcome of head and neck cancer patients following re-irradiation. Patients and Methods: A total of 51 patients with recurrent or second primary head and neck cancer received re-irradiation at Leuven University Hospital. Survival and locoregional control were calculated. Doses to organs at risk were retrieved from dosevolume histograms. Radiation-related toxicities were reported. Results: The 2-year actuarial overall survival rate was 30%. On univariate analysis, surgery before re-irradiation and high radiation dose were associated with superior survival. Grade 3 acute and grade 3 or more late toxicity occurred in respectively 29.4% and 35.3% of the patients. Conclusion: Re-irradiation in head and neck cancer patients is feasible with acceptable late toxicity, although the survival remains poor.

As the number of cancer survivors grows because of advances in therapy, it has become more important to understand the longterm complications of these treatments. This article presents the current knowledge of adverse cardiovascular effects of radiotherapy to the chest. Emphasis is on clinical presentations, recommendations for follow-up, and treatment of patients previously exposed to irradiation. Medline TM literature searches were performed, and abstracts related to this topic from oncology and cardiology meetings were reviewed. Potential adverse effects of mediastinal irradiation are numerous and can include coronary artery disease, pericarditis, cardiomyopathy, valvular disease and conduction abnormalities. Damage appears to be related to dose, volume and technique of chest irradiation. Effects may initially present as subclinical abnormalities on screening tests or as catastrophic clinical events. Estimates of relative risk of fatal cardiovascular events after mediastinal irradiation for Hodgkin's disease ranges between 2.2 and 7.2 and after irradiation for left-sided breast cancer from 1.0 to 2.2. Risk is life long, and absolute risk appears to increase with length of time since exposure. Radiation-associated cardiovascular toxicity may in fact be progressive. Long-term cardiac follow-up of these patients is therefore essential, and the range of appropriate cardiac screening is discussed, although no specific, evidencebased screening regimen was found in the literature. #

Advances in dose-volume/outcome (or normal tissue complication probability, NTCP) modeling since the seminal Emami paper from 1991 are reviewed. There has been some progress with an increasing number of studies on large patient samples with three-dimensional dosimetry. Nevertheless, NTCP models are not ideal. Issues related to the grading of side effects, selection of appropriate statistical methods, testing of internal and external model validity, and quantification of predictive power and statistical uncertainty, all limit the usefulness of much of the published literature. Synthesis (meta-analysis) of data from multiple studies is often impossible because of suboptimal primary analysis, insufficient reporting and variations in the models and predictors analyzed. Clinical limitations to the current knowledge base include the need for more data on the effect of patient-related cofactors, interactions between dose distribution and cytotoxic or molecular targeted agents, and the effe...