Efficacy of Small Bowel Displacement System in Post-Operative Pelvic Radiation Therapy of Rectal Cancer / 대한방사선종양학회지

PURPOSE: This study is to evaluate the efficacy of small bowel displacement system (SBDS) in post-operative pelvic radiation therapy (RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. MATERIALS AND METHOD: Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink Gastrographin before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using picture archiving and communication system (PACS). RESULTS: The average small bowel volumes with and without SBDS were 176.0ml (5.2- 415.6ml) and 185.1ml (54.5- 434.2ml), respectively. The changes of small bowel volume with SBDS compared to those without SBDS were more than 10% decrease in three, less than 10% decreaseintwo,lessthan10%increaseinthree,andmorethan10%increaseintwopatients. CONCLUSION: No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.

Early and Late Bowel Complication Following Irradiation of Cancer of the Uterine Cervix-Whole Pelvis Exlernal : Irradiation end High-Dose-Rate Inlracavitary Irradiation / 대한치료방사선과학회지

Cervix cancer is the most common female cancer in Korea. In spite of their relatively local invasive tendency, still 44% of patient will develop recurrent cancer This result suggests that more aggressive local treatment may increase the cure rate but increased complication risk also cannot be avoidable. Various institutions proposed different treatment regimen, but recommended dose were about 4500 cGy for whole pelvis and 8000 cGy at point A, even though they agreed that those doses may not be satisfactory for control of bulky disease. 96 cases of invasive cervical cancer, treated with postoperative or primary radiation therapy were analyzed to determine the complication rate and prognostic factor in our treatment regimen which is 500~1000 cGy higher than other institution. Mean follow up duration was 21 months. Symptomatic patients including mild but persistent abdominal discomfort was 46%, but only 1 patient (1%) had operative treatment because of incomplete obstruction of small bowel. Most symptoms appeared within 12 months and most common complaints were frequent bowel movement. Barium enema and sigmoidoscopy were performed for persistent symptomatic patients. Only one patient had abnormal finding in barium enema which showed inefficiency of this method for detecting bowel complication. Patient's age, total tumor dose, total TDF, rectal dose were not significant risk factors for complication, but boost dose, previous history of operation had some relationship with complication risk. Even though dose of point A and rectum is 500~1,000 cGy higher than other institution, such a low rate of severe complications may suggest that fear of complications should not be overestimated than cure rate and the possibility of more aggressive treatment for better local control should not be underestimated.