Tumor control probability analysis in carbon-ion radiotherapy for prostate cancer considering the oxygen effect

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics Pub Date : 2026-03-01 Epub Date: 2026-02-10 DOI:10.1016/j.ejmp.2026.105744

Yushi Wakisaka , Shuka Fukuda , Toshiro Tsubouchi , Noriaki Hamatani , Masashi Yagi , Mayu Nakata , Yuki Tominaga , Kazuhiko Hayashi , Masaaki Takashina , Kazumasa Minami , Teiji Nishio , Tatsuaki Kanai

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引用次数: 0

Abstract

Purpose

Carbon ion radiotherapy (CIRT) is expected to be effective against hypoxic tumors due to its lower oxygen enhancement ratio (OER) compared to X-ray radiotherapy (XRT). OER is expected to have a significant impact on therapeutic efficacy, especially for prostate cancer, which has low oxygen partial pressure. This study aimed to derive OERs for photon and carbon-ion spread-out Bragg peak (SOBP) irradiation through cellular experiments and incorporate them into the tumor control probability (TCP) function to test consistency with clinical outcomes.

Methods

To derive the OER for photons and the OERs at three depths (proximal, center, and distal) within the carbon-ion SOBP, the dose-dependent survival rate of the prostate cancer cell line PC3 was measured under both aerobic and hypoxic conditions. TCP functions incorporating dose-dependent OERs based on clinical prescription doses were fitted to clinical outcomes of prostate cancer treated with XRT and CIRT to test the clinical relevance of the obtained OERs.

Results

The OERs at 10% survival for PC3 cells were 2.12 ± 0.68 for photons, and 1.70 ± 0.13, 1.65 ± 0.19, and 1.56 ± 0.13 at the proximal, center, and distal depths of the carbon-ion SOBP, respectively. The TCP functions calculated using dose-dependent OERs were not inconsistent with the clinical outcomes for both XRT and CIRT, supporting the clinical relevance of the OERs derived from cell experiments.

Conclusion

The carbon-ion SOBP used in prostate cancer treatment has a lower OER than photons, suggesting its potential effectiveness against hypoxic tumors.

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考虑氧效应的前列腺癌碳离子放疗肿瘤控制概率分析。

目的：碳离子放射治疗（CIRT）与x射线放射治疗（XRT）相比，氧增强比（OER）更低，有望有效治疗缺氧肿瘤。OER有望对治疗效果产生重大影响，特别是对于低氧分压的前列腺癌。本研究旨在通过细胞实验推导光子和碳离子铺展布拉格峰（SOBP）辐照的OERs，并将其纳入肿瘤控制概率（TCP）函数，检验其与临床结果的一致性。方法：为了获得光子的OER以及碳离子SOBP内近、中、远三个深度（近、中、远）的OER，测量了前列腺癌细胞系PC3在有氧和缺氧条件下的剂量依赖性存活率。结合基于临床处方剂量的剂量依赖性OERs的TCP函数与XRT和CIRT治疗前列腺癌的临床结果拟合，以检验所获得的OERs的临床相关性。结果：光子对PC3细胞10%存活率的OERs分别为2.12±0.68，碳离子SOBP近端、中心和远端深度的OERs分别为1.70±0.13、1.65±0.19和1.56±0.13。使用剂量依赖性OERs计算的TCP函数与XRT和CIRT的临床结果并不矛盾，支持来自细胞实验的OERs的临床相关性。结论：碳离子SOBP用于前列腺癌治疗的OER低于光子，提示其对低氧肿瘤的潜在疗效。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Physica Medica-European Journal of Medical Physics 生物-生物物理

CiteScore

6.80

自引率

14.70%

发文量

493

审稿时长

78 days

期刊介绍： Physica Medica, European Journal of Medical Physics, publishing with Elsevier from 2007, provides an international forum for research and reviews on the following main topics: Medical Imaging Radiation Therapy Radiation Protection Measuring Systems and Signal Processing Education and training in Medical Physics Professional issues in Medical Physics.