Feng Ziwei, Tao Cheng, Zhu Jian, Chen Jinhu, Yu Gang, Qin Shaohua, Yin Yong, Li Dengwang
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Biomedical Sciences, School of Physics and Electronics, Shandong Normal University, No.88, Wenhua East Road, Lixia District, Jinan, 250014, China.
Department of Radiation Oncology, Shandong Cancer Hospital and Institute, No.440, Jiyan Road, Jinan, 250117, China.
Radiat Oncol. 2017 Apr 4;12(1):64. doi: 10.1186/s13014-017-0784-1.
For cervical carcinoma cases, this study aimed to evaluate the quality of intensity-modulated radiation therapy (IMRT) plans optimized by biological constraints. Furthermore, a new integrated strategy in biological planning module was proposed and verified.
Twenty patients of advanced stage cervical carcinoma were enrolled in this study. For each patient, dose volume optimization (DVO), biological model optimization (BMO) and integrated strategy optimization (ISO) plans were created using same treatment parameters. Different biological models were also used for organ at risk (OAR) in BMO plans, which include the LKB and Poisson models. Next, BMO plans were compared with their corresponding DVO plans, in order to evaluate BMO plan quality. ISO plans were also compared with DVO and BMO plans, in order to verify the performance of the integrated strategy.
BMO plans produced slightly inhomogeneity and less coverage of planning target volume (PTV) (V95=96.79, HI = 0.10: p < 0.01). However, the tumor control probability (TCP) value, both from DVO and BMO plans, were comparable. For the OARs, BMO plans produced lower normal tissue complication probability (NTCP) of rectum (NTCP = 0.11) and bladder (NTCP = 0.14) than in the corresponding DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder; p < 0.01 for rectum and p = 0.03 for bladder). V95, D98, CI and HI values that were produced by ISO plans (V95 = 98.31, D98 = 54.18Gy, CI = 0.76, HI = 0.09) were greatly better than BMO plans (V95 = 96.79, D98 = 53.42Gy, CI = 0.71, HI = 0.10) with significant differences. Furthermore, ISO plans produced lower NTCP values of rectum (NTCP = 0.14) and bladder (NTCP = 0.16) than DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder, respectively) with significant differences.
BMO plans produced lower NTCP values of OARs compared to DVO plans for cervical carcinoma cases, and resulted in slightly less target coverage and homogeneity. The integrated strategy, proposed in this study, could improve the coverage, conformity and homogeneity of PTV greater than the BMO plans, as well as reduce the NTCP values of OARs greater than the DVO plans.
对于宫颈癌病例，本研究旨在评估通过生物约束优化的调强放射治疗（IMRT）计划的质量。此外，还提出并验证了生物计划模块中的一种新的综合策略。
本研究纳入了20例晚期宫颈癌患者。对于每位患者，使用相同的治疗参数创建剂量体积优化（DVO）计划、生物模型优化（BMO）计划和综合策略优化（ISO）计划。在BMO计划中，还对危及器官（OAR）使用了不同的生物模型，包括LKB模型和泊松模型。接下来，将BMO计划与其相应的DVO计划进行比较，以评估BMO计划的质量。还将ISO计划与DVO计划和BMO计划进行比较，以验证综合策略的性能。
BMO计划产生的不均匀性略小，计划靶区（PTV）的覆盖范围略小（V95 = 96.79，HI = 0.10：p < 0.01）。然而，DVO计划和BMO计划的肿瘤控制概率（TCP）值相当。对于OAR，BMO计划产生的直肠正常组织并发症概率（NTCP = 0.11）和膀胱正常组织并发症概率（NTCP = 0.14）低于相应的DVO计划（直肠和膀胱的NTCP分别为0.19和0.18；直肠p < 0.01，膀胱p = 0.03）。ISO计划产生的V95、D98、CI和HI值（V95 = 98.31，D98 = 54.18Gy，CI = 0.76，HI = 0.09）明显优于BMO计划（V95 = 96.79，D98 = 53.42Gy，CI = 0.71，HI = 0.10），差异显著。此外，ISO计划产生的直肠NTCP值（NTCP = 0.14）和膀胱NTCP值（NTCP = 0.16）低于DVO计划（直肠和膀胱的NTCP分别为0.19和0.18），差异显著。
对于宫颈癌病例，与DVO计划相比，BMO计划产生的OAR的NTCP值更低，且靶区覆盖范围和均匀性略小。本研究提出的综合策略能够比BMO计划更好地提高PTV的覆盖范围、适形性和均匀性，同时比DVO计划更大程度地降低OAR的NTCP值。
