盆腔肿瘤调强与三维适形放疗肠道勾画与剂量-体积限制的研究进展

在盆腔肿瘤的放射治疗过程中，肠道损伤是重要的不良反应。随着调强放射治疗（IMRT）等精准放疗技术的广泛应用，正常组织器官的受照剂量已大幅下降。然而，肠道的不良反应仍限制了靶区剂量的提高。故在给予病灶足够照射剂量的同时，对肠道等重要危及器官（OAR）的保护变得更加重要。目前多数研究采用基于肠管的勾画方法，采用小肠+结肠勾画，对于2级急性不良反应，有意义的剂量-体积预测指标包括V_{45 Gy}<50 cm³，V_{50 Gy}<13 cm³，V_{55 Gy}<3 cm³；采用肠袋勾画，对于2级不良反应，有意义的预测指标包括V_{40 Gy}< 170 cm³，V_{45 Gy}< 100 cm³，V_{50 Gy}< 33 cm³。

Advances in bowel delineation and dose-volume constraint in intensity modulated radiation therapy and 3D conformal radiation therapy for pelvic tumors

Intestinal injury is an important toxic response during radiation therapy of pelvic tumors. With the widespread use of precision radiotherapy techniques such as intensity modulated radiation therapy (IMRT), the dose exposed to normal tissues and organs has been significantly reduced. However, the toxic response of the bowel still limits the increase of the dose to the target volume. Therefore, the protection of important organs at risk (OAR), such as the bowel, becomes more and more important while giving adequate irradiated dose to the target volume. Most current studies used loop to contour bowel. For patients who underwent IMRT, the meaningful dose-volume predictors of grade 2 acute intestinal adverse events using bowel loop (small loop + big bowel) delineation included V_{45 Gy} < 50 cm³, V_{50 Gy} < 13 cm³, and V_{55 Gy} < 3 cm³, and the corresponding predicators using bowel bag delineation were V_{40 Gy} < 170 cm³, V_{45 Gy} < 100 cm³, and V_{50 Gy} < 33 cm³.