Division of Radiation Oncology, The University of Texas M D Anderson Cancer Center, Houston, TX 77030, USA.
Phys Med Biol. 2010 Dec 7;55(23):7055-65. doi: 10.1088/0031-9155/55/23/S07. Epub 2010 Nov 12.
Hepatocellular carcinoma (HCC), the sixth most common cancer in the world, is a global health concern. Radiotherapy for HCC is uncommon, largely because of the likelihood of radiation-induced liver disease, an acute side effect that is often fatal. Proton beam therapy (PBT) and intensity-modulated radiation therapy (IMRT) may offer HCC patients a better option for treating the diseased liver tissue while largely sparing the surrounding tissues, especially the non-tumor liver. However, even advanced radiotherapies carry a risk of late effects, including second malignant neoplasms (SMNs). It is unclear whether PBT or IMRT confers less risk of an SMN than the other. The purpose of this study was to compare the predicted risk of developing an SMN for a patient with HCC between PBT and IMRT. For both treatments, radiation doses in organs and tissues from primary radiation were determined using a treatment planning system; doses in organs and tissues from stray radiation from PBT were determined using Monte Carlo simulations and from IMRT using thermo-luminescent dosimeter measurements. Risk models of SMN incidence were taken from the literature. The predicted absolute lifetime attributable risks of SMN incidence were 11.4% after PBT and 19.2% after IMRT. The results of this study suggest that using proton beams instead of photon beams for radiotherapy may reduce the risk of SMN incidence for some HCC patients.
肝细胞癌 (HCC) 是全球第六大常见癌症，也是全球关注的健康问题。 HCC 的放射治疗并不常见，主要是因为可能发生放射性肝损伤，这是一种常见的急性副作用，通常是致命的。质子束治疗 (PBT) 和调强放射治疗 (IMRT) 可能为 HCC 患者提供更好的治疗患病肝脏组织的选择，同时很大程度上保护周围组织，特别是非肿瘤肝脏。然而，即使是先进的放射治疗也有发生晚期效应的风险，包括第二恶性肿瘤 (SMN)。目前尚不清楚 PBT 或 IMRT 是否比另一种治疗方法具有更低的 SMN 风险。本研究的目的是比较 HCC 患者接受 PBT 和 IMRT 治疗时，SMN 发生风险的预测值。对于两种治疗方法，使用治疗计划系统确定来自初级辐射的器官和组织中的辐射剂量；使用蒙特卡罗模拟确定来自 PBT 的散射线和来自 IMRT 的热释光剂量计测量的器官和组织中的剂量。SMN 发病风险模型取自文献。PBT 后 SMN 发病的预测绝对终生归因风险为 11.4%，IMRT 后为 19.2%。本研究结果表明，对于某些 HCC 患者，使用质子束而不是光子束进行放射治疗可能会降低 SMN 发病的风险。
