# Superficial and orthovoltage radiotherapy for skin cancer

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

## TL;DR

Low-energy X-rays that stop within a few millimetres, used to cure basal and squamous cell skin cancers where surgery would scar or is not wanted.

## Summary

Superficial (50 to 150 kV) and orthovoltage (150 to 300 kV) X-ray units were the first radiotherapy machines and are still the right tool for many skin cancers of the face, ears and lower legs, with cure rates comparable to surgery for small basal and squamous cell carcinomas and better cosmetic results in some sites. Electronic brachytherapy devices and electron beams cover the same ground. They are also used for keloids and benign conditions.

## Fields

- Kind: Technology
- Status: established
- Last checked: 2026-09-16
- Tags: radiation-wave1
- Principle: Low-energy photons deposit their dose at the skin surface and fall off rapidly with depth, treating the lesion with little dose to underlying tissue.
- Since: 1900
- Strengths: Non-invasive cure for skin cancers; Good cosmesis in the face; Cheap, simple machines
- Limitations: Multiple visits; Late skin changes over years; Less suitable in young patients

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Orthovoltage_X-rays

## Connected records

- cancers: [Basal cell carcinoma](https://onco.cc/cancers/basal-cell-carcinoma/), [Cutaneous squamous cell carcinoma](https://onco.cc/cancers/cutaneous-scc/), [Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)](https://onco.cc/cancers/cutaneous-t-cell-lymphoma/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)

---
JSON: https://onco.cc/api/v1/entities/superficial-radiotherapy.json