Kuipers Sander, Godart Jérémy, Corbeau Anouk, Sharfo Abdul Wahab, Breedveld Sebastiaan, Mens Jan Willem, de Boer Stephanie, Nout Remi, Hoogeman Mischa
Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, Netherlands.
Department of Medical Physics and Informatics, HollandPTC, Delft, Netherlands.
Front Oncol. 2023 Jun 28;13:1138433. doi: 10.3389/fonc.2023.1138433. eCollection 2023.
To quantify the increase in bladder and rectum dose of a bone marrow sparing (BMS) VMAT strategy for primary treatment of locally advanced cervical cancer (LACC).
Twenty patients with stage IB-IVA cervical cancer were selected for this study. The whole Pelvic Bones (PB) was taken as substitute for bone marrow. For every patient, Pareto-optimal plans were generated to explore the trade-off between rectum, bladder, and PB mean dose. The PB mean dose was decreased in steps of 1 Gy. For each step, the increase in rectum and bladder mean dose was quantified. The increase in mean dose of other OAR compared to no BMS was constrained to 1 Gy.
In total, 931 plans of 19 evaluable patients were analyzed. The average [range] mean dose of PB without BMS was 22.8 [20.7-26.2] Gy. When maximum BMS was applied, the average reduction in mean PB dose was 5.4 [3.0-6.8] Gy resulting in an average mean PB dose of 17.5 [15.8-19.8] Gy. For <1 Gy increase in both the bladder and the rectum mean dose, the PB mean dose could be decreased by >2 Gy, >3 Gy, >4 Gy, and >5 Gy for 19/19, 13/19, 5/19, and 1/19 patients, respectively.
Based on the comprehensive three-dimensional Pareto front analysis, we conclude that 2-5 Gy BMS can be implemented without a clinically relevant increase in mean dose to other OAR. If BMS is too dominant, it results in a large increase in mean dose to other OAR. Therefore, we recommend implementing moderate BMS for the treatment of LACC patients with VMAT.
量化用于局部晚期宫颈癌（LACC）初始治疗的骨髓保护（BMS）容积调强弧形放疗（VMAT）策略中膀胱和直肠剂量的增加情况。
本研究选取了20例IB-IVA期宫颈癌患者。将整个骨盆骨（PB）作为骨髓的替代物。对于每位患者，生成帕累托最优计划以探索直肠、膀胱和PB平均剂量之间的权衡。PB平均剂量以1 Gy的步长降低。对于每一步，量化直肠和膀胱平均剂量的增加情况。与无BMS相比，其他危及器官（OAR）平均剂量的增加被限制在1 Gy。
总共分析了19例可评估患者的931个计划。无BMS时PB的平均[范围]剂量为22.8 [20.7 - 26.2] Gy。当应用最大程度的BMS时，PB平均剂量的平均降低量为5.4 [3.0 - 6.8] Gy，导致PB平均剂量为17.5 [15.8 - 19.8] Gy。对于膀胱和直肠平均剂量增加均<1 Gy的情况，PB平均剂量分别可为19/19、13/19、5/19和1/19例患者降低>2 Gy、>3 Gy、>4 Gy和>5 Gy。
基于全面的三维帕累托前沿分析，我们得出结论，实施2 - 5 Gy的BMS不会导致其他OAR的平均剂量出现临床相关增加。如果BMS过于占主导地位，则会导致其他OAR的平均剂量大幅增加。因此，我们建议在VMAT治疗LACC患者时实施适度的BMS。
