Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Review Randomized Controlled Trial Multicenter Study Clinical Trial
The volume effect in radiation-related late small bowel complications: results of a clinical study of the EORTC Radiotherapy Cooperative Group in patients treated for rectal carcinoma.
The purpose of this study was to quantify the correlation between irradiated small bowel volume and late occurring small bowel complications. ⋯ This study demonstrated that there is a volume-effect in radiation-induced diarrhea at a dose of 50 Gy in 25 fractions. No volume-effect for small bowel obstruction was detected at this dose-level in pelvic postoperative radiotherapy. A review of the literature data on small bowel obstruction indicates that the volume effect at this dose level can only be demonstrated in patients who were treated with extended field radiotherapy (estimated small bowel volume 800 cm3) after intra-abdominal surgery.
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The purpose of this study was to analyse whether the intended patient setup, based on a CT scan, was different from the setup at the simulator. Furthermore, we investigated how these possible transfer errors between the planned patient setup and the actual simulator setup affected the resulting overall treatment setup accuracy. Two groups, of 15 prostate patients each, were studied. ⋯ For group I, the SDs of the resulting overall setup deviations during treatment were 1.6 mm and 4.1 mm in the x- and y-direction, respectively. For group II, these figures were 2.4 mm and 2.6 mm, respectively. For both groups, the magnitude of the overall mean was less than 1.0 mm.(ABSTRACT TRUNCATED AT 250 WORDS)
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Peripheral nerve appears to be a dose-limiting normal tissue in the clinical application of intraoperative radiation therapy (IORT). To assess IORT injury to peripheral nerve, three groups of five beagle dogs received doses of 12, 20 or 28 Gy to the surgically exposed and isolated right sciatic nerve in the mid-femoral region using 6 MeV electrons. The left sciatic nerve of each dog served as its own control. ⋯ Results showed that the threshold dose most likely related to expression of severe radiation damage to the nerve in this model is between 20 and 25 Gy. Radiation injury to peripheral nerve appears to be the result of direct radiation effects on Schwann cells and nerve vasculature and secondary effects resulting from damage to regional muscle and vasculature. A theoretical mechanism of radiation injury to peripheral nerve is proposed.
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Absence of a dose-response relationship has been reported for local control of Hodgkin's disease between 30 and 42 Gy delivered to the mantle field in definitive irradiation. These dose ranges were determined at the central ray using irregular field (IF) calculations without benefit of dosimetric correction for lung inhomogeneity. Detailed analysis was performed of dose delivered to hilar and mediastinal regions with mantle field irradiation incorporating lung inhomogeneity corrections for the indicated dose ranges using 60Co and 6 MV linear accelerator. ⋯ Mantle field calculations should be performed with CT planning including lung inhomogeneity corrections to account for anatomic irregularity of the mediastinal contour and interposed lung. As lung inhomogeneity dosimetric data become available, conclusions drawn from clinical experience should be re-evaluated based upon location and extent of mediastinal disease involvement. Implications for treatment associated late toxicity using dose-volume histogram analysis should be considered.
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Randomized Controlled Trial Clinical Trial Controlled Clinical Trial
Late radiation injuries of the gastrointestinal tract in the H2 and H5 EORTC Hodgkin's disease trials: emphasis on the role of exploratory laparotomy and fractionation.
Out of 516 patients who entered in the two successive EORTC trials H2 and H5 for supra-diaphragmatic stages I and II Hodgkin's disease (HD), and who received an infra-diaphragmatic irradiation, 36 (7%) developed late radiation injuries of the gastrointestinal tract (GIT). Twenty-five patients presented with ulcers (stomach or duodenum), 2 with severe gastritis, 6 with small bowel obstruction or perforation and 3 patients had both an ulcer and bowel obstruction. A previous laparotomy played an important role. ⋯ When combining laparotomy and fractionation, we found that the patients who were treated using 5 weekly fractions of 2 Gy without any prior laparotomy had a very low rate of late digestive complications (1%), whereas the patients who received 3 weekly fractions of 3.3 Gy after laparotomy presented a 39% complication rate. The other subgroups of patients were at an intermediate risk (from 5 to 13%) of late digestive injuries. Since most patients received 40 Gy with only very small variations, the influence of the radiation dose could not be investigated.(ABSTRACT TRUNCATED AT 250 WORDS)