Papers by Karin Haustermans
International Journal of Radiation Oncology*Biology*Physics, 2007
Acta oncologica (Stockholm, Sweden), 2016
Rectal cancer patients who achieve a good response to chemoradiotherapy (CRT), may be offered les... more Rectal cancer patients who achieve a good response to chemoradiotherapy (CRT), may be offered less invasive surgery or even no surgery at all. Implementation of such a policy, however, requires precise patient selection. This study identifies pretreatment clinical factors that are associated with pathological complete response (pCR) and ypT0-1N0 and evaluates their performance as a selection tool for organ-preserving strategies. Patients with rectal cancer treated with CRT and total mesorectal excision between January 2000 and December 2014 were retrospectively included. Following clinical characteristics were extracted from the medical files: age, gender, body mass index, ASA score, cT-stage, cN-stage, distance from the anal verge, pretreatment carcinoembryonic antigen (CEA), pretreatment hemoglobin and distance from the mesorectal fascia. Univariable and multivariable binary logistic regression models were used to predict pCR and ypT0-1N0. The discriminative ability of the predict...
Critical Reviews in Oncology/Hematology, 2015
Radiotherapy and Oncology, 2015
Boosting the dose to the largest (dominant) lesion in radiotherapy of prostate cancer may improve... more Boosting the dose to the largest (dominant) lesion in radiotherapy of prostate cancer may improve treatment outcome. The success of this approach relies on the detection and delineation of tumors. The agreement among teams of radiation oncologists and radiologists delineating lesions on multiparametric magnetic resonance imaging (mp-MRI) was assessed by measuring the distances between observer contours. The accuracy of detection and delineation was determined using whole-mount histopathology specimens as reference. Six observer teams delineated tumors on mp-MRI of 20 prostate cancer patients who underwent a prostatectomy. To assess the inter-observer agreement, the inter-observer standard deviation (SD) of the contours was calculated for tumor sites which were identified by all teams. Eighteen of 89 lesions were identified by all teams, all were dominant lesions. The median histological volume of these was 2.4cm(3). The median inter-observer SD of the delineations was 0.23cm. Sixty-six of 69 satellites were missed by all teams. Since all teams identify most dominant lesions, dose escalation to the dominant lesion is feasible. Sufficient dose to the whole prostate may need to be maintained to prevent under treatment of smaller lesions and undetected parts of larger lesions.
European Journal of Cancer Supplements, 2009
Acta chirurgica Belgica
The use of imaging in the follow-up of patients after curative colorectal cancer resection is muc... more The use of imaging in the follow-up of patients after curative colorectal cancer resection is much debated. The American Society of Colon and Rectal Surgeons did not recommend routine imaging. This retrospective study assesses the yield of routine imaging to detect recurrent disease. In 1998, 108 consecutive patients underwent curative resection for colorectal carcinoma. Minimum followup in our institution was 3 years. Multidisciplinary follow-up at a joint clinic consisted out of a history, clinical examination, serum carcinoembryonic antigen (CEA), chest X-ray and abdominal ultrasound, at least every 6 months. Colonoscopy was performed within 1 year after operation and every 3 to 5 years thereafter. The incidence, timing, means of detection and resectability of recurrence were studied. The recurrence rate was 22% (24 patients): liver metastases (11), extra-hepatic recurrence (10) and combined recurrence (3). Recurrent disease occurred in stage II or III cancer, except for two pati...
Seminars in radiation oncology, 2014
The success of highly conformal radiotherapy techniques in the sparing of normal tissues or in do... more The success of highly conformal radiotherapy techniques in the sparing of normal tissues or in dose escalation, or both, relies heavily on excellent imaging. Because of its superior soft tissue contrast, magnetic resonance imaging is increasingly being used in radiotherapy treatment planning. This review discusses the current clinical evidence to support the pivotal role of magnetic resonance imaging in radiation oncology.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2007
Molecular imaging, in particular, PET, has brought an additional dimension to management for pati... more Molecular imaging, in particular, PET, has brought an additional dimension to management for patients with cancer. 18F-FDG, which is the most widely available tracer, has been shown to be of value for the selection of target volumes in radiation oncology. Depending on its sensitivity and specificity, 18F-FDG has been shown to influence the selection of target volumes for non-small cell lung cancers (NSCLC) or for esophageal tumors. On the other hand, for tumors such as head and neck squamous cell carcinomas (HNSCC) and rectal carcinomas, convincing data on the value of 18F-FDG for target volume selection are still lacking. For target volume delineation, given that an adequate method is used for volume segmentation, the added value of 18F-FDG has been demonstrated for HNSCC and NSCLC. For both types of tumors, modifications in target volume delineation translated into differences in dose distribution compared with the results of CT scan-based plans. Studies are in progress for rectal...
Radiotherapy and Oncology, 2011
Radiotherapy and Oncology, 2009
Purpose: To assess the feasibility and efficacy of the COX-2 inhibitor celecoxib in conjunction w... more Purpose: To assess the feasibility and efficacy of the COX-2 inhibitor celecoxib in conjunction with preoperative chemoradiation for patients with locally advanced rectal cancer in a double blind randomized phase II study. Materials and methods: Thirty-five patients of the initially planned 80 patients with locally advanced rectal cancer were treated with preoperative radiation (45 Gy; 1.8 Gy/fraction, 5 days/week) combined with 5-fluorouracil (continuous infusion, 225 mg/m 2 /day) and celecoxib (2 Â 400 mg/day) or placebo. Pathological response and toxicity of study treatment were evaluated, as well as expression of COX-2 and Ki67 in tumor tissue and IL-6 in plasma as possible molecular correlates and predictors of response to treatment. Results: Patients treated with celecoxib tended to show a better response (61%) when compared to those treated with placebo (35%), although not significant (p = 0.13). T-downstaging and N-downstaging were also slightly higher with celecoxib. Plasma IL-6 levels and intratumoral COX2 or Ki67 were altered by chemoradiation, but were not further altered by celecoxib treatment and therefore not useful for prediction of treatment benefit. Celecoxib therapy in conjunction with chemoradiation was not associated with additional toxicity and seemed to help mitigate therapy-related pain. Conclusions: Addition of celecoxib to preoperative chemoradiation is feasible for patients with locally advanced rectal cancer. To study the individual effect of COX-2 inhibitors on pathological response phase III studies are required.
Radiation Oncology, 2008
The primary objective of this study was to determine the maximum tolerated dose (MTD) of escalati... more The primary objective of this study was to determine the maximum tolerated dose (MTD) of escalating doses of radiotherapy (RT) concomitantly with a fixed dose of gemcitabine (300 mg/m 2 /week) within the same overall treatment time.
Urologic Oncology: Seminars and Original Investigations, 2015
Purpose: Accurate staging modalities to diagnose lymph node involvement in patients with prostate... more Purpose: Accurate staging modalities to diagnose lymph node involvement in patients with prostate cancer (PCa) are lacking. We wanted to prospectively assess sensitivity, specificity, and positive predictive value (PPV) and negative predictive value of 11 C-choline positron emission tomography (PET)-computed tomography (CT) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for nodal staging in patients with PCa at high risk for lymph node involvement.
Radiotherapy and Oncology, 1997
In 18 patients the perfusion of a malignant head and neck tumour was estimated using contrast enh... more In 18 patients the perfusion of a malignant head and neck tumour was estimated using contrast enhanced dynamic computed tomography. The mean estimated perfusion was 75.5 ml/100 g/min, varying between 27.9 and 131.9. Eleven patients were treated with radiation therapy; the obtained perfusion rates were significantly different between tumours with a favourable and those with an unfavourable early outcome.
Annals of Oncology, 2014
ABSTRACT Background: The PETACC-6 trial investigates whether the addition of oxaliplatin to preop... more ABSTRACT Background: The PETACC-6 trial investigates whether the addition of oxaliplatin to preoperative oral fluoropyrimidine-based chemoradiation (CRT) followed by postoperative adjuvant fluoropyrimidine-based chemotherapy (CT) improves disease-free survival (DFS) in locally advanced rectal cancer. Methods: Between 11/2008 and 09/2011, patients with rectal adenocarcinoma within 12 cm from the anal verge, T3/4 and/or node-positive, with no evidence of metastatic disease and considered either resectable at the time of entry or expected to become resectable, were randomly assigned to receive 5 weeks of preoperative CRT with capecitabine, followed by 6 cycles of adjuvant CT with capecitabine with (arm 2) or without (arm 1) the addition of oxaliplatin before and after surgery. 440 DFS events were required to have 80% power to detect an improvement in 3-year DFS from 65% with capecitabine alone to 72% with capecitabine and oxaliplatin (HR=0.763) using a two-sided alpha of 5% and owing for an interim analysis for early efficacy at 200 events. The primary analysis was intent-to-treat and adjusted for stratification factors (clinical T category, nodal status, distance from the tumor to the anal verge and method of locoregional staging) except the center. Results: 1094 patients were randomized (547 in each arm). 543 eligible patients in arm 1 and 526 in arm 2 started their allocated treatment of whom 67.4% completed protocol treatment in arm 1 vs. 53.8% in arm 2. An independent data monitoring committee reviewed the interim data and recommended the early release of the results. At median follow-up of 31 months, respectively 124 and 121 DFS events were observed in arm 1 and 2 (adjusted HR=1.036, 95% CI: 0.806 -1.331, P=0.781). 3-year DFS was 74.5% (95% CI: 70.1% - 78.3%) in arm 1, which is higher than anticipated vs. 73.9% (95% CI: 69.5% - 77.8%) in arm 2. Conditional power under HR=0.763 is only 7%. Conclusions: Interim results indicate that the addition of oxaliplatin to capecitabine plus radiotherapy does not improve DFS. Careful follow-up should continue until the planned 440 events to document any late treatment difference
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of...
Positron emission tomography (PET) using the positron emitting glucose analogue 18F-fluorodeoxygl... more Positron emission tomography (PET) using the positron emitting glucose analogue 18F-fluorodeoxyglucose (FDG) has emerged as a useful metabolism-based wholebody imaging tool for gastro-esophageal cancer diagnosis and follow up. Most large cancer centers worldwide are now equipped for PET (or even PET-CT). Therefore, there is a growing need for a clear definition of the relative position of PET within the currently available diagnostic modalities. Significant scientific data indicate that FDG-PET adds clinically useful information to the information obtained by standard means (mainly CT and endoscopic ultrasound) throughout the different phases of clinical patient management: 1) at initial diagnosis: PET detects more frequently distant lymph node involvement and organ metastases compared to conventional diagnostics, allowing a more accurate selection of the most appropriate treatment; 2) during chemotherapy: semi-quantitative FDG-PET allows early identification of non-responding patie...
Urology, 2007
The radiotherapy panel met to develop international consensus about the optimal use of radiothera... more The radiotherapy panel met to develop international consensus about the optimal use of radiotherapy, alone or in combination with surgery and chemotherapy, in the radical treatment of patients with bladder cancer. A consensus meeting of experts in the treatment of bladder cancer was convened by the Société Internationale d'Urologie (SIU). The radiotherapy committee, which had international representation from 6 countries, performed a critical review of the English-language literature and developed evidence-based guidelines for the use of radiotherapy in the treatment of patients with bladder cancer. The strength of the evidence supporting each recommendation was ranked according to a 4-point scale. Consensus statements were developed that address (1) the effectiveness of radiotherapy in the treatment of bladder cancer, (2) the most appropriate patients for curative treatment with radiotherapy, (3) the optimal method of delivery of radiotherapy, (4) the best radiation prescription for treating bladder cancer, and (5) optimal management of the patient's condition after radiotherapy has been provided. Radiotherapy is effective treatment for selected patients with bladder cancer; it produces long-term disease control with preservation of normal bladder function. Modern radiotherapy treatment techniques offer the potential to improve cure rates and reduce adverse effects. All patients in whom the condition is newly diagnosed should be assessed in a multidisciplinary setting, where the relative merits of surgery, radiotherapy, and chemotherapy can be considered on an individual basis with the aim of optimizing overall outcomes. UROLOGY 69 (Suppl 1A): 80 -92, 2007.
Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy have become standard... more Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy have become standard treatments but are more sensitive to anatomical variations than 3D conformal techniques. To correct for inter- and intrafraction anatomical variations, fast and easy to implement methods are needed. Here, the authors propose a full dosimetric IMRT correction that finds a compromise in-between basic repositioning (the current clinical practice) and full replanning. It simplifies replanning by avoiding a recontouring step and a full dose calculation. It surpasses repositioning by updating the preoptimized fluence and monitor units (MU) using a limited number of fiducial points and a pretreatment (CB)CT. To adapt the fluence the fiducial points were projected in the beam's eye view (BEV). To adapt the MUs, point dose calculation towards the same fiducial points were performed. The proposed method is intrinsically fast and robust, and simple to understand for operators, because of the use of only four fiducial points and the beam data based point dose calculations. To perform our dosimetric adaptation, two fluence corrections in the BEV are combined with two MU correction steps along the beam's path. (1) A transformation of the fluence map such that it is realigned with the current target geometry. (2) A correction for an unintended scaling of the penumbra margin when the treatment beams scale to the current target size. (3) A correction for the target depth relative to the body contour and (4) a correction for the target distance to the source. The impact of the correction strategy and its individual components was evaluated by simulations on a virtual prostate phantom. This heterogeneous reference phantom was systematically subjected to population based prostate transformations to simulate interfraction variations. Additionally, a patient example illustrated the clinical practice. The correction strategy was evaluated using both dosimetric (CTV mean dose, conformity index) and clinical (tumor control probability, and normal tissue complication probability) measures. Based on the current experiments, the intended target dose and tumor control probability could be assured by the proposed method (TCP ≥ TCP(intended)). Additionally, the conformity index error was more than halved compared to the current clinical practice (ΔCI(95%) from 40% to 16%) resulting in improved organ at risk protection. All the individual correction steps had an added value to the full correction. A limited number of fiducial points (no organ contours required) and an in-room (CB)CT are sufficient to perform a full dosimetric correction for IMRT plans. In the presence of interfraction variation, the corrected plans show superior dose distributions compared to our current clinical practice.
Radiotherapy and Oncology, 2010
The present chapter is focused on the role of positron emission tomography/computed tomography (P... more The present chapter is focused on the role of positron emission tomography/computed tomography (PET/ CT) and [11C]-labelled Choline ([11C]Choline) for the management of prostate cancer patients for radiation therapy planning.
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Papers by Karin Haustermans