Health Technology Assessment of Carbon-ion Beam Radiotherapy: A Systematic Review of Clinical Effectiveness and Safety for 54 Oncological Indications in 12 Tumour Regions.

Abstract

Due to the unique physical dose distribution of carbon-ion radiotherapy (CIRT), CIRT can be regarded as a novel tumour irradiation technique - potentially advantageous for various tumour types. Yet it is unclear in how far, superiority or inferiority can be claimed when comparing CIRT to standard irradiation. This study aimed to assess the scientific evidence regarding the effectiveness and safety of CIRT. A systematic literature review was performed using the European Network for Health Technology Assessment (EUnetHTA) Core Model® for rapid relative effectiveness assessment. The literature search for clinical outcome studies on CIRT was performed using four databases [Cochrane (Central), Centre for Research and Dissemination (CRD), Embase and OVID MEDLINE]. The Cochrane Risk of Bias Tool (for randomised controlled trials) and the Institute of Health Economics (IHE-18) Checklist (for observational studies) were used to assess the risk of bias of the included studies. The evidence synthesis was restricted to 54 oncological indications in 12 broad tumour regions and studies with a low or moderate risk of bias, published between 2005 and 2017. Twenty-seven studies were eligible for the qualitative synthesis of the evidence regarding the effectiveness and safety of CIRT: One randomised controlled trial that primarily focused on the feasibility of CIRT, three case-control studies, three before- and after- studies with a focus on quality of life, and 20 further studies of case series. Overall, insufficient scientific evidence was found for superiority or inferiority of CIRT when compared to standard irradiation for 13/54 oncologicaI indications in 7/12 tumour regions (skull base tumours, brain cancer, cancer in the ear-nose-throat region, bone and soft-tissue tumours, lung cancer, prostate cancer, gastrointestinal tumours). No scientific evidence was found for the remaining 41/54 oncological indications. CIRT is undoubtedly, theoretically, a promising cancer treatment. To date, however, it lacks randomised controlled trials assessing the long-term effectiveness and harms associated with the use of CIRT. CIRT must be considered as an experimental treatment due to the lack of high-quality clinical research.