重离子放疗（如碳离子放疗[CIRT]）与传统的光子疗法相比有多重优势。顺铂是一种经典的抗肿瘤药物，在多个细胞系中（包括头颈鳞状细胞癌[HNSCC]）已被测试并发现具有光子放射线增敏作用。因此，我们的研究旨在评估顺铂是否能在体外增敏CIRT对HNSCC细胞系。人鼻咽癌细胞系CNE-2、人舌鳞癌细胞系TCA 8113和人下咽癌鳞状细胞癌细胞系FADU均接受2、4、6、8 Gy（物理剂量）的光子束辐射和1、2、3、4 Gy的碳离子束辐射以及顺铂处理。通过克隆形成存活试验评估了细胞存活情况。CIRT显示出比标准的光子放射线治疗更强的细胞毒性效应。在10%生存下，碳离子束的相对生物学有效性（RBE10）对于CNE-2、TCA 8113和FADU分别为3.07、2.33和2.36。化学放疗（包括光子放射线放疗和CIRT）比单独放射线治疗更有效。在体内，经过光子辐射后，顺铂在CNE-2、TCA 8113和FADU细胞系中的增感比（SER）分别为1.33、1.14和1.21，在碳离子辐照后分别为1.02、1.00和0.96，表明顺铂增感了光子辐射，但在所有测试的细胞系中对碳离子辐射没有增感效果。综上所述，具有高线性能量转移（LET）的CIRT比光子辐射更有效地防止HNSCC细胞系的增殖。顺铂的额外治疗可以增敏光子辐射，但对碳离子辐射没有影响。版权所有©2023方、孙、董、黄、卢和孔。

Heavy ion radiotherapy, such as carbon ion radiotherapy (CIRT), has multiple advantages over conventional photon therapy. Cisplatin, as a classic anti-tumor drugs, has been tested and discovered as a photon radiosensitizer in several cell lines, including head and neck squamous cell carcinoma (HNSCC). Hence, the aim of our study is to evaluate whether cisplatin can sensitize CIRT towards HNSCC cell lines in vitro.Human nasopharyngeal carcinoma cell line CNE-2, human tongue squamous carcinoma cell line TCA 8113 and human hypopharynx squamous carcinoma cell line FADU were all irradiated with photon beam of 2, 4, 6, 8 Gy (physical dose) and carbon ion beam of 1, 2, 3, 4 Gy (physical dose) and treated with cisplatin. Cell survival was assessed by clonogenic survival assay.CIRT showed significantly stronger cytotoxic effect than standard photon radiotherapy. The relative biological effectiveness (RBE) of carbon ion beam at 10% survival ( R B E 10 ) was calculated 3.07 for CNE-2, 2.33 for TCA 8113 and 2.36 for FADU. Chemoradiotherapy (both photon radiotherapy and CIRT) was more effective than radiotherapy alone. In vitro sensitizer enhancement ratios (SERs) of cisplatin in CNE-2, TCA 8113 and FA DU cell lines after photon irradiation were 1.33, 1.14 and 1.21, while after carbon ion irradiation were 1.02, 1.00 and 0.96, showed that cisplatin sensitized photon irradiation but showed no sensitization effect in carbon ion irradiation in all tested cell lines.In conclusion, high linear energy transfer (LET) CIRT was more effective than photon irradiation to prevent the proliferation of HNSCC cell lines. Additional treatment with cisplatin could sensitize photon irradiation but showed no effect on carbon ion irradiation.Copyright © 2023 Fang, Sun, Dong, Huang, Lu and Kong.