Hollenhorst Helmut, Schaffer Moshe, Romano Mario, Reiner Michael, Siefert Axel, Schaffer Pamela, Quanz Anton, Dühmke Eckhart
Department of Radiation Oncology, Ludwig-Maximilians University, Munich, Germany.
Med Dosim. 2004 Fall;29(3):173-8. doi: 10.1016/j.meddos.2004.04.004.
The purpose of this study was to determine the feasibility of a custom-made, modified bellyboard to reduce radiotherapy side effects on small bowel, bladder, skin, and male gonads. Two groups of 10 consecutive patients each were treated from January 2003 through April 2003 with neoadjuvant (45 Gy) or adjuvant (54 Gy) radio(chemo)therapy in single fractions of 5 days a week 1.8 Gy for rectal carcinoma, using a photon energy of 15 MV. One group was positioned in a prone position without an immobilization device, the other group was positioned on our bellyboard. Treatment planning was calculated by using a 4- and a 3-field box technique. Differences in the dose of organs of risk were calculated. For 1 male patient, a gonadal shielding was developed and integrated. All patients examined with the bellyboard demonstrated an anterior and cranial dislocation of the small bowel. Using a 4-field box, the mean dose to the small bowel of patients treated on our bellyboard was 56.5% as compared to 63.1% when treated without the bellyboard. When a 3-field box was used, the mean dose to the small bowel was 52.4% when the bellyboard was used, as compared to a mean dose of 63.1% without the bellyboard. Regarding the dose volume effects to the bladder, the mean dose for patients treated with a 4-field box was about 14.5% higher as compared to patients treated with a 3-field box. The mean dose to the hip joints and skin also depended on the radiation technique. The patient who received gonadal shielding received a maximal total gonadal dose of about 75.0 cGy in single fractions of maximal 3.0 cGy (TL-dosimeters). Daily setup variations evaluated by a beam's-eye view were similar in both groups and ranged from 0.5 cm 1.0 cm. For daily use, our bellyboard appears to be an ideal compromise due to effectiveness, its easy handling, and reproductive positioning; moreover, it can also be used in combination with gonadal shielding.
本研究的目的是确定定制的改良腹板对于减少直肠癌放疗对小肠、膀胱、皮肤和男性性腺的副作用的可行性。2003年1月至2003年4月，两组各10例连续患者接受新辅助（45 Gy）或辅助（54 Gy）放（化）疗，每周5天，每天单次剂量1.8 Gy，采用15 MV光子能量治疗直肠癌。一组采用俯卧位且无固定装置，另一组采用我们的腹板进行定位。使用4野和3野盒式技术进行治疗计划计算。计算危及器官剂量的差异。为1例男性患者制作并整合了性腺屏蔽。所有使用腹板检查的患者均显示小肠向前和头侧移位。使用4野盒式技术时，使用我们腹板治疗的患者小肠平均剂量为56.5%，而未使用腹板治疗时为63.1%。使用3野盒式技术时，使用腹板时小肠平均剂量为52.4%，未使用腹板时平均剂量为63.1%。关于膀胱的剂量体积效应，使用4野盒式技术治疗的患者平均剂量比使用3野盒式技术治疗的患者高约14.5%。髋关节和皮肤的平均剂量也取决于放疗技术。接受性腺屏蔽的患者最大性腺总剂量在单次最大3.0 cGy（热释光剂量计）时约为75.0 cGy。通过射野视角评估的两组每日摆位变化相似，范围为0.5 cm至1.0 cm。对于日常使用，我们的腹板由于有效性、易于操作和生殖器官定位等优点，似乎是一个理想的折衷方案；此外，它还可与性腺屏蔽联合使用。
