Evidence-based Oncology

Traditional oncology distinguishes between two separate and incommensurable states in the evolution of solid malignancies: the localized disease, which is curable; and the disseminated status, which is per se palliative. Recently, a huge body of evidence suggests a fundamental change in the understanding of cancer, indicating an intermediate state in the trajectory of solid malignancies: the oligometastatic state. The following review will critically analyse existing hypotheses and facts from the basic sciences and try to contextualize it in regard to the clinical evidence available to date. Consecutively, it will try to draw possible clinical consequences for application of radiotherapy in this specific clinical scenario.

"Image-guided intensity-modulated radiotherapy for patients with locally advanced gastric cancer: a clinical feasibility study.
Badakhshi H, Gruen A, Graf R, Boehmer D, Budach V.
Source: Gastric Cancer. 2013 Oct 11.
Department for Radiation Oncology, Charité School of Medicine and University Hospital Berlin, Augustenburger Platz 1, 13353, Berlin, Germany, Harun.Badakhshi@charite.de.
Abstract
BACKGROUND:
The aim of this study was to determine the medical and technical feasibility of intensity-modulated radiotherapy (IMRT) in high-risk nonmetastatic gastric cancer stage II and III after primary gastrectomy and D2 lymphadenectomy.
METHODS AND MATERIALS:
A prospective nonrandomized phase II trial was performed on 25 consecutive patients with gastric cancer with high risk (T3-4, N1-3, G2-3, R0-1). The dose delivered was 45 Gy (1.80 Gy per fraction) in IMRT technique. Concurrent 5-fluorouracil-based chemotherapy at 225 mg/m2 was administered as a continuous intravenous infusion. Primary endpoints were acute gastrointestinal toxicity (CTC 4.0) and technical feasibility of IMRT in regard to dose planning and radiation delivery.
RESULTS:
Early acute events were defined as clinical and chemical adverse effects of IMRT and concurrent chemotherapy during treatment. By definition, 90 days after the end of IMRT has been evaluated as acute-phase toxicity. No patient had grade 4 or higher acute adverse events. Clinical grade 3 toxicity occurred in two patients (8 %) with diarrhea and in one case (4 %) with nausea. Hematological changes with grade 3 occurred in three cases (12 %) with hemoglobin decrease, in five cases (25 %) as leukopenia, and in one case (4 %) with thrombocytopenia. The mean dose for liver was 16 Gy and the percentage volume exceeding 30 Gy (V30) was 21 %. Mean dose for right and left kidney was 9 and 13 Gy, respectively, and V20 was 9 % and 13 %, respectively. Heart received a median dose of 15 Gy and V40 was 17 %. The mean dose to the bowel was 11 Gy and V40 was 6 %. Spinal cord had at maximum 33 Gy in median. Specifics of dose distribution, including the coverage, for the target region were as follows: minimum was 33 Gy, maximum 48.6 Gy, and mean dose 44.6 Gy. The prescribed dose (45 Gy) covered 99 % and 95 % of planning target volume (OTV) in 66 % and 92 % of cases, respectively. Median PTV was 15.77 ml (range, 805-3,604 ml).
CONCLUSIONS:
The data support the practical feasibility of IMRT in adjuvant treatment in high-risk gastric cancer in the postoperative setting as a proof of principle. Acute toxicity has been tolerable."

Traditional oncology distinguishes between two separate and incommensurable states in the evolution of solid malignancies: the localized disease, which is curable; and the disseminated status, which is per se palliative. Recently, a huge body of evidence suggests a fundamental change in the understanding of cancer, indicating an intermediate state in the trajectory of solid malignancies: the oligometastatic state. The following review will critically analyse existing hypotheses and facts from the basic sciences and try to contextualize it in regard to the clinical evidence available to date.