# Dose–Volume Constraints for Thoracic, Abdominal, and Pelvic Carbon Ion Radiotherapy: A Literature Review

## TL;DR

This paper reviews dose-volume constraints for carbon ion radiotherapy in thoracic, abdominal, and pelvic regions to guide safe treatment planning.

## Contribution

The paper compiles and classifies dose–volume constraints for CIRT based on Japanese RBE models, aiding treatment prioritization.

## Key findings

- Dose–volume constraints are reported for multiple organs including lungs, liver, and rectum.
- Constraints are categorized as hard or soft to guide treatment planning priorities.
- Further research is needed to verify and expand these constraints for uninvestigated organs.

## Abstract

Applying dose–volume constraints is extremely important in ensuring the safe use of radiotherapy. However, constraints for carbon ion radiotherapy (CIRT) have not been established yet. This review aims to summarize dose–volume constraints for thoracic, abdominal, and pelvic CIRT that have been identified through previous research based on the Japanese models for relative biological effectiveness (RBE).

Constraints are reported for the lungs, liver, stomach, gastrointestinal tract, rectum, sigmoid, bladder, nerves, rib, femoral head, sacrum, and skin. The constraints are classified into hard and soft to aid in determining whether priority should be given to the target coverage or organ‐at‐risk (OAR) sparing during treatment planning.

Further research is necessary to verify the applicability of the reported constraints and to identify constraints for the OARs that have not been investigated yet.