First image-guided treatment of a mouse tumor with radioactive ion beams

TL;DR

This study demonstrates the first successful image-guided treatment of a mouse tumor using radioactive ion beams, combining precise PET imaging with targeted radiotherapy to improve accuracy and reduce toxicity.

Contribution

It introduces the novel application of radioactive ion beams for tumor treatment, enabling real-time PET imaging for precise dose delivery in cancer therapy.

Findings

Complete tumor control with minimal toxicity.

Correlation between positron activity and neurological side effects.

Dose-dependent biological washout indicating vascular damage.

Abstract

Radioactive ion beams (RIB) are a key focus of current research in nuclear physics. Already long ago it was proposed that they could have applications in cancer therapy. In fact, while charged particle therapy is potentially the most effective radiotherapy technique available, it is highly susceptible to uncertainties in the beam range. RIB are well-suited for image-guided particle therapy, as isotopes that undergo \b{eta}+-decay can be precisely visualized using positron emission tomography (PET), enabling accurate real-time monitoring of the beam range. We successfully treated a mouse osteosarcoma using a radioactive 11C-ion beam. The tumor was located in the neck, in close proximity to the spinal cord, increasing the risk of radiation-induced myelopathy from even slight variations in the beam range caused by anatomical changes or incorrect calibration of the planning CT. We managed to completely control the tumor with the highest dose while minimizing toxicity. Low-grade neurological side effects were correlated to the positron activity measured in the spine. The biological washout of the activity from the tumor volume was dependent on the dose, indicating a potential component of vascular damage at high doses. This experiment marks the first instance of tumor treatment using RIB and paves the way for future clinical applications.