宫颈癌术后放疗保留卵巢功能的剂量评估

Dose assessment of preserving ovarian function by radiotherapy after cervical cancer surgery

目的比较静态调强放疗技术(IMRT)和容积旋转调强放疗技术(VMAT)对于宫颈癌患者治疗中保护卵巢功能的能力。方法选取17例进行宫颈癌术后放射治疗且需要保留卵巢功能的年轻患者作为研究对象。在原有计划靶区体积(PTV)的基础上,分别设计和执行卵巢保护的IMRT和VMAT。记录两种技术组患者的PTV、卵巢、膀胱、肠袋、脊髓、股骨头、直肠的剂量参数并进行分析。比较IMRT与VMAT在保护卵巢功能的宫颈癌放疗计划中的差异性。结果IMRT卵巢的最大剂量(D_(max))和平均剂量(D_(mean))显著低于VMAT;IMRT靶区的最小剂量(D_(min))高于VMAT(P<0.05);IMRT脊髓D_(max)、D_(mean)以及膀胱接受40 Gy照射的体积百分比(V40)均低于VMAT(P<0.05)。IMRT在保护卵巢功能方面优于VMAT。接受IMRT 17例患者中,11例患者成功保留卵巢功能。结论剂量参数分析结果表明,患者在接受宫颈癌放射治疗时,IMRT技术在保留卵巢功能方面具有更显著优势。

Aim To compare the ability of static intensity-modulated radiotherapy technique(IMRT)and volumetric modulate arc therapy(VMAT)to preserve ovarian function in the treatment of patients with cervical cancer.Methods Seventeen young patients who underwent postoperative radiotherapy for cervical cancer and required preservation of ovarian function were selected for the study.Based on the original planned target volume(PTV),the IMRT and VMAT plans for ovarian protection were designed and performed separately.The dose parameters of the PTV,ovary,bladder,bowel pouch,spinal cord,femoral head and rectum were recorded and analyzed for patients in each group of the plan.The differences between the IMRT and the VMAT in radiotherapy plans for cervical cancer with protection of ovarian function are compared.Results The maximum dose(D_(max))and mean dose(D_(mean))to the ovaries were significantly lower for the IMRT technique than for the VMAT technique;the minimum dose(D_(min))to the target area was higher for the IMRT technique than for the VMAT technique(P<0.05);the spinal cord D_(max),D_(mean) and the percentage of volume of the bladder irradiated with 40 Gy(V40),were all lower for IMRT than for VMAT(P<0.05).IMRT was superior to VMAT in protecting ovarian function.In 17 patients treated with the IMRT technique,ovarian function was successfully preserved in 11 patients.Conclusion The results of the dose parameter analysis suggest that the IMRT technique is more significantly advantageous in preserving ovarian function when patients are recommended for radiotherapy for cervical cancer in this study.