# Radiodynamic therapy and radiosensitising nanoparticles

Source: https://onco.cc/technologies/radiodynamic-therapy/  
OnCo record `radiodynamic-therapy` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Nanoparticles that turn ordinary radiotherapy X-rays into a much bigger dose exactly where they sit.

## Summary

High atomic-number nanoparticles absorb X-rays disproportionately and either release secondary electrons, amplifying local dose, or excite a linked photosensitiser to produce singlet oxygen at depth. Hafnium-oxide nanoparticles (NBTXR3) are the most advanced dose-enhancement agent, with a randomised soft-tissue sarcoma study behind them and head and neck work ongoing. True radiodynamic constructs, where the particle drives a photochemical reaction, remain early phase.

## Fields

- Kind: Technology
- Status: phase-2
- Last checked: 2026-09-08
- Tags: frontier; promising
- Principle: Intratumoural high-Z nanoparticles increase local photoelectric absorption, multiplying dose delivered per gray to the tumour without raising dose to surrounding tissue.
- Strengths: Amplifies an existing, widely available treatment; Physical mechanism, so genotype-independent; One intratumoural injection lasts a whole course
- Limitations: Requires an injectable, well-distributed tumour; Distribution within the tumour is uneven; Benefit beyond the injected site is unproven

## Sources

- ClinicalTrials.gov: NBTXR3: https://clinicaltrials.gov/search?term=NBTXR3

## Connected records

- cancers: [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/)
- technologies: [Hyperthermia](https://onco.cc/technologies/hyperthermia/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Photoimmunotherapy & photodynamic therapy](https://onco.cc/technologies/photoimmunotherapy/), [SBRT / SABR (stereotactic radiotherapy)](https://onco.cc/technologies/sbrt/)
- roadmaps: [Devices and physical therapies roadmap: heat and light → electric fields and focused sound → drug-releasing implants](https://onco.cc/roadmaps/devices-roadmap/), [Radical oncology: what could change the war by 2035](https://onco.cc/roadmaps/frontier-2035/), [Radiotherapy roadmap: X-rays → shaped beams → fewer fractions, particles and FLASH](https://onco.cc/roadmaps/radiation-roadmap/)

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