The Ewha Medical Journal
Ewha Womans University School of Medicine
Review

Clinical indications and future directions of carbon-ion radiotherapy: a narrative review

Seo Hee Choi1, Woong Sub Koom1, Hong In Yoon1, Kyung Hwan Kim1, Chan Woo Wee1, Jaeho Cho1, Yong Bae Kim1, Ki Chang Keum1, Ik Jae Lee1,*
1Department of Radiation Oncology, Heavy Ion Therapy Research Institute, Yonsei Cancer Center, Yonsei University Health System, Yonsei University College of Medicine, Korea, Seoul 03722, Korea.
*Corresponding Author: Ik Jae Lee, Department of Radiation Oncology, Heavy Ion Therapy Research Institute, Yonsei Cancer Center, Yonsei University Health System, Yonsei University College of Medicine, Korea, Seoul 03722, Korea, Republic of. E-mail: ikjae412@yuhs.ac.

© Copyright 2024 Ewha Womans University School of Medicine. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Sep 02, 2024; Revised: Sep 23, 2024; Accepted: Sep 23, 2024

Published Online: Oct 31, 2024

Abstract

Carbon-ion radiotherapy (CIRT) offers superior dose distributions and greater biological effectiveness than conventional photon-based radiotherapy (RT). Due to its higher linear energy transfer and relative biological effectiveness, CIRT is particularly effective against radioresistant tumors and those located near critical organs. Since the first dedicated CIRT facility was established in Japan in 1994, CIRT has demonstrated remarkable efficacy against various malignancies, including head and neck tumors, skull base and upper cervical spine tumors, non-small-cell lung cancer (NSCLC), hepatocellular carcinoma (HCC), pancreatic cancer, prostate cancer, and bone and soft tissue sarcomas. This narrative review provides a comprehensive overview of the current status of CIRT, highlighting its clinical indications and future directions. According to clinical studies, CIRT achieves high local control rates with manageable toxicity across multiple cancer types. For instance, in head and neck tumors (e.g., adenoid cystic carcinoma and mucosal melanoma), CIRT has achieved local control rates exceeding 80%. In early-stage NSCLC, CIRT has resulted in local control rates over 90% with minimal toxicity. Moreover, CIRT has shown promise in treating challenging cases of HCC and pancreatic cancer, where conventional therapies are limited. Nonetheless, the global adoption of CIRT remains limited due to high costs and complexity. Future directions include conducting randomized controlled trials to establish high-level evidence, integrating new technologies such as ultrahigh-dose-rate (FLASH) therapy, and expanding CIRT facilities globally with strategic planning and cost-effectiveness analyses. If these challenges are addressed, CIRT is poised to play a transformative role in cancer treatment, improving survival rates and the quality of life.

Keywords: Carbon-ion radiotherapy; Charged particle therapy; Bragg peak; review; Radioresistant tumors