Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile.
Departament de Física, Universitat Autónoma de Barcelona, Bellaterra, Spain.
Phys Med. 2019 Oct;66:88-96. doi: 10.1016/j.ejmp.2019.09.076. Epub 2019 Sep 29.
To perform a systematic and thorough assessment, using the Uncomplicated and Cancer-Free Control Probability (UCFCP) function, of a broad range of photon prostate cancer RT treatments, on the same scenario (a unique pelvic CT set). UCFCP considers, together with the probabilities of local tumour control (TCP) and deterministic (late) sequelae (NTCP), the second primary cancer risk (SPCR) due to photon and neutron peripheral doses.
Thirty-six radiotherapy plans were produced for the same CT. 6, 10, 15 and 18 MV 3DCRT, IMRT and VMAT (77.4 Gy in 43 fractions) and 6 and 10 MV SBRT (36.25 Gy in 5 fractions with flattened and FFF beams) for Elekta, Siemens and Varian Linacs plans were included. DVH and peripheral organ dosimetry were used to compute TCP, NTCP, and SPCR (the competition and LNT models) for further plan ranking.
Biological models (and parameters) used predicted an outcome which is in agreement with epidemiological findings. SBRT plans showed the lowest SPCR and a below average NTCP. High energy plans did not rank worse than the low energy ones. Intensity modulated plans were ranked above the 3D conformal techniques.
According to UCFCP, the best plans were the10 MV SBRTs. SPCR rates were low and did not show a substantial impact on plan ranking. High energy intensity-modulated plans did not increase in excess the average of SPCR. Even more, they ranked among the best, provided that MU were efficiently managed.
使用无并发症且无癌症控制概率（UCFCP）函数，对同一情况下（一组独特的骨盆 CT）广泛的光子前列腺癌放射治疗方案进行系统全面的评估。UCFCP 考虑了局部肿瘤控制（TCP）和确定性（晚期）后遗症（NTCP）的概率，以及光子和中子外周剂量引起的第二原发癌风险（SPCR）。
为同一 CT 生成了 36 个放疗计划。包括 Elekta、西门子和瓦里安直线加速器的 6、10、15 和 18 MV 3DCRT、IMRT 和 VMAT（43 个分次 77.4Gy）和 6 和 10 MV SBRT（5 个分次 36.25Gy，平坦化和 FFF 束）。使用剂量体积直方图和外周器官剂量学来计算 TCP、NTCP 和 SPCR（竞争和 LNT 模型），以便进一步对计划进行排名。
所使用的生物学模型（和参数）预测的结果与流行病学发现一致。SBRT 计划显示出最低的 SPCR 和低于平均水平的 NTCP。高能计划的排名并不比低能计划差。调强计划的排名高于三维适形技术。
根据 UCFCP，最好的计划是 10 MV SBRT。SPCR 率较低，对计划排名没有实质性影响。高能调强计划不会过度增加 SPCR 的平均值。更重要的是，只要 MU 得到有效管理，它们就可以排在前列。
