Olofsen-van Acht M, van den Berg H, Quint S, de Boer H, Seven M, van Sömsen de Koste J, Creutzberg C, Visser A
Department of Radiation Oncology, University Hospital Rotterdam - Daniel den Hoed Cancer Center, Division of Clinical Physics and Instrumentation, Groene Hilledijk 301, 3075 EA, The, Rotterdam, Netherlands.
Radiother Oncol. 2001 Apr;59(1):87-93. doi: 10.1016/s0167-8140(00)00279-6.
To reduce the volume of small bowel within pelvic treatment fields for gynecological cancer using a bellyboard device and to determine the accuracy of the prone treatment position.
Fifteen consecutive patients with a gynecologic malignancy who were treated with postoperative pelvic radiotherapy were selected for this study. The volume of small bowel within the treatment fields was calculated for both the supine and prone treatment positions. The patients were treated in the prone position in a so-called bellyboard device. During treatment sessions electronic portal images were obtained. An off-line setup verification and correction protocol was used and the setup accuracy of the positioning in the bellyboard was determined.
The average volume of small bowel within the treatment fields was 229 cm(3) and 66 cm(3) in the supine and prone treatment, respectively, which means an average volume reduction in the prone position of 64% (95% CI 56-72%), as compared with the supine position. For the position of the patient in the field, the systematic error defined by the standard deviation (SD) of the mean difference per patient between simulation and treatment images was 1.7 mm in the lateral direction, 2.1 mm in the craniocaudal direction and 1.7 mm in the ventrodorsal direction. On average, only 0.4 setup correction per patient was required to achieve this accuracy. The random day-to-day variations were 1.9 (1SD), 2.6 and 2.3 mm, respectively. Standard deviations of the systematic differences between patient positioning relative to the bellyboard were 6.2 mm in lateral direction and 9.1 mm in craniocaudal direction.
Treatment of gynecological cancer patients in the prone position using a bellyboard reduces the volume of irradiated small bowel. An off-line verification and correction protocol ensures accurate patient positioning. Daily setup variations using the bellyboard were small (1 SD<3 mm). Therefore for pelvic radiotherapy in patients with a gynecological malignancy, the use of a bellyboard is recommended.
使用腹托装置减少妇科癌症盆腔治疗野内小肠的体积，并确定俯卧位治疗的准确性。
本研究选取了15例接受术后盆腔放疗的妇科恶性肿瘤患者。计算仰卧位和俯卧位治疗时治疗野内小肠的体积。患者在所谓的腹托装置中采用俯卧位进行治疗。在治疗过程中获取电子门静脉图像。使用离线设置验证和校正方案，并确定在腹托中定位的设置准确性。
仰卧位和俯卧位治疗时，治疗野内小肠的平均体积分别为229 cm³和66 cm³，这意味着与仰卧位相比，俯卧位的平均体积减少了64%（95%可信区间56 - 72%）。对于患者在野内的位置，模拟图像与治疗图像之间每位患者平均差异的标准差（SD）所定义的系统误差在横向为1.7 mm，在颅尾方向为2.1 mm，在腹背方向为1.7 mm。平均而言，每位患者仅需0.4次设置校正即可达到此准确性。日常随机变化分别为1.9（1SD）、2.6和2.3 mm。患者相对于腹托的定位系统差异的标准差在横向为6.2 mm，在颅尾方向为9.1 mm。
使用腹托对妇科癌症患者进行俯卧位治疗可减少照射小肠的体积。离线验证和校正方案可确保患者准确定位。使用腹托的每日设置变化较小（1 SD < 3 mm）。因此，对于妇科恶性肿瘤患者的盆腔放疗，建议使用腹托。
