Retrospective comparison of rectal toxicity between carbon-ion radiotherapy and intensity-modulated radiation therapy based on treatment plan, normal tissue complication probability model, and clinical outcomes in prostate cancer

• Published in: Physica medica 2021-10, Vol.90, p.6-12
• Main Authors: Fukata, Kyohei, Kawamura, Hidemasa, Kubo, Nobuteru, Kanai, Tatsuaki, Torikoshi, Masami, Nakano, Takashi, Tashiro, Mutsumi, Ohno, Tatsuya
• Format: Article
• Language: English
• Subjects: Carbon-ion radiation therapy; Normal tissue complication probability; Prostate cancer
• ISSN: 1120-1797; 1724-191X
• DOI: 10.1016/j.ejmp.2021.08.013

•Carbon-ion radiation therapy and photon radiation therapy using IMRT were compared.•Carbon-ion radiation therapy showed lower rectal EQD2-converted DVH, EQD3-converted DVH, and NTCP.•Both modalities showed comparable rectal toxicity in clinical outcome. This retrospective study assessed the treatment planning data and clinical outcomes for 152 prostate cancer patients: 76 consecutive patients treated by carbon-ion radiation therapy and 76 consequtive patients treated by moderate hypo-fractionated intensity-modulated photon radiation therapy. These two modalities were compared using linear quadratic model equivalent doses in 2 Gy per fraction for rectal or rectal wall dose–volume histogram, 3.6 Gy per fraction-converted rectal dose–volume histogram, normal tissue complication probability model, and actual clinical outcomes. Carbon-ion radiation therapy was predicted to have a lower probability of rectal adverse events than intensity-modulated photon radiation therapy based on dose–volume histograms and normal tissue complication probability model. There was no difference in the clinical outcome of rectal adverse events between the two modalities compared in this study.