Michaud Anne-Victoire, Samain Benoit, Ferrer Ludovic, Fleury Vincent, Doré Mélanie, Colombié Mathilde, Dupuy Claire, Rio Emmanuel, Guimas Valentine, Rousseau Thierry, Le Thiec Maelle, Delpon Grégory, Rousseau Caroline, Supiot Stéphane
Nuclear Medicine Department, Institut de Cancérologie de l'Ouest, 44805 Nantes Saint-Herblain, France.
Radiation Oncology Department, Institut de Cancérologie de l'Ouest, 44805 Nantes Saint-Herblain, France.
Cancers (Basel). 2020 Apr 10;12(4):944. doi: 10.3390/cancers12040944.
Prostate cancer (PCa) pelvic radiotherapy fields are defined by guidelines that do not consider individual variations in lymphatic drainage. We examined the feasibility of personalized sentinel lymph node (SLN)-based pelvic irradiation in PCa. Among a SLN study of 202 patients, we retrospectively selected 57 patients with a high risk of lymph node involvement. Each single SLN clinical target volume (CTV) was individually segmented and pelvic CTVs were contoured according to Radiation Therapy Oncology Group (RTOG) guidelines. We simulated a radiotherapy plan delivering 46 Gy and calculated the dose received by each SLN. Among a total of 332 abdominal SLNs, 305 pelvic SLNs (beyond the aortic bifurcation) were contoured (mean 5.4/patient). Based on standard guidelines, CTV missed 67 SLNs (22%), mostly at the common iliac level (40 SLNs). The mean distance between iliac vessels and the SLN was 11mm, and despite a 15mm margin around the iliac vessels, 9% of SLNs were not encompassed by the CTV. Moreover, 42 SLNs (63%) did not receive 95% of the prescribed dose. Despite a consensus on contouring guidelines, a significant proportion of SLNs were not included in the pelvic CTV and did not receive the prescribed dose. A tailored approach based on individual SLN detection would avoid underdosing pelvic lymph nodes that potentially contain tumor cells.
前列腺癌（PCa）盆腔放疗野是根据未考虑淋巴引流个体差异的指南来定义的。我们研究了基于个性化前哨淋巴结（SLN）的PCa盆腔照射的可行性。在一项对202例患者的SLN研究中，我们回顾性选择了57例有淋巴结受累高风险的患者。对每个单独的SLN临床靶区（CTV）进行个体化分割，并根据放射治疗肿瘤学组（RTOG）指南勾画盆腔CTV。我们模拟了一个给予46 Gy的放疗计划，并计算每个SLN所接受的剂量。在总共332个腹部SLN中，勾画了305个盆腔SLN（在主动脉分叉以下）（平均每位患者5.4个）。根据标准指南，CTV遗漏了67个SLN（22%），主要在髂总水平（40个SLN）。髂血管与SLN之间的平均距离为11mm，尽管在髂血管周围有15mm的边界，但9%的SLN未被CTV覆盖。此外，42个SLN（63%）未接受规定剂量的95%。尽管在勾画指南上达成了共识，但仍有相当比例的SLN未被纳入盆腔CTV且未接受规定剂量。基于个体SLN检测的定制方法将避免对可能含有肿瘤细胞的盆腔淋巴结剂量不足。
