目的:这项配对队列研究的目的是评估强度调节质子治疗(IMPT)在骨盆骨髓搏击中的潜力,从而与强度调节光子放疗(IMRT)相比,降低血液毒性妇科恶性肿瘤的术后放疗。次要终点是评估应用IMPT时发生骶骨功能不全骨折(SIF)的预测参数。材料和方法:对两组患者进行分析,每组25例。与IMRT相比,患者接受IMPT治疗,患有子宫颈(n=8)或子宫内膜癌(n=17)。剂量处方,患者年龄,和诊断匹配。传递到整个骨盆骨骼和亚部位的剂量学参数(髂骨,腰骶部,骶骨,和下骨盆)和血液学毒性进行了评估。用于评估SIF的MRI随访仅适用于IMPT组。结果:在IMPT组中,骨盆骨骼的积分剂量显着降低(23.4GyRBEvs34.3Gy;p<0.001),平均V5Gy,V10Gy,和V20Gy减少了40%,41%,28%,分别,与IMRT组相比(p<0.001)。特别是,对于髂骨和下骨盆,低剂量体积明显降低。血液毒性在IMRT组中明显更常见(80%vs32%;p=0009),尤其是血液毒性≥CTCAEII(36%vs8%;p=0.037)。IMPT组没有患者出现血液毒性>CTCAEII。在IMPT队列中,32%的患者经历了SIF。与45GyRBE(22%)相比,总剂量为50.4GyRBE(37.5%)的总SIF发生频率更高。除了关于V50Gy到腰骶亚位点的趋势之外,没有检测到关于SIF的显著预测剂量参数。结论:与匹配的光子队列相比,使用IMPT可以显着降低骨盆骨骼的低剂量暴露,从而降低血液毒性。骶骨功能不全骨折率与文献中报道的IMRT率相似。
Purpose: The aim of this matched-pair cohort study was to evaluate the potential of intensity-modulated proton therapy (IMPT) for sparring of the pelvic bone marrow and thus reduction of
hematotoxicity compared to intensity-modulated photon radiotherapy (IMRT) in the setting of postoperative irradiation of gynaecological malignancies. Secondary endpoint was the assessment of predictive parameters for the occurrence of sacral insufficiency fractures (SIF) when applying IMPT. Materials and Methods: Two cohorts were analyzed consisting of 25 patients each. Patients were treated with IMPT compared with IMRT and had uterine cervical (n = 8) or endometrial cancer (n = 17). Dose prescription, patient age, and diagnosis were matched. Dosimetric parameters delivered to the whole pelvic skeleton and subsites (ilium, lumbosacral, sacral, and lower pelvis) and hematological toxicity were evaluated. MRI follow-up for evaluation of SIF was only available for the IMPT group. Results: In the IMPT group, integral dose to the pelvic skeleton was significantly lower (23.4GyRBE vs 34.3Gy; p < 0.001), the average V5Gy, V10Gy, and V20Gy were reduced by 40%, 41%, and 28%, respectively, compared to the IMRT group (p < 0.001). In particular, for subsites ilium and lower pelvis, the low dose volume was significantly lower.
Hematotoxicity was significantly more common in the IMRT group (80% vs 32%; p = 0009), especially
hematotoxicity ≥ CTCAE II (36% vs 8%; p = 0.037). No patient in the IMPT group experienced
hematotoxicity > CTCAE II. In the IMPT cohort, 32% of patients experienced SIF. Overall SIF occurred more frequently with a total dose of 50.4 GyRBE (37.5%) compared to 45 GyRBE (22%). No significant predictive dose parameters regarding SIF could be detected aside from a trend regarding V50Gy to the lumbosacral subsite. Conclusion: Low-dose exposure to the pelvic skeleton and thus
hematotoxicity can be significantly reduced by using IMPT compared to a matched photon cohort. Sacral insufficiency fracture rates appear similar to reported rates for IMRT in the literature.