Estimation of the carcinogenic risk of radiotherapy of benign diseases from shoulder to heel

Abstract

Background and purpose: To estimate risk on fatal tumour induction in patients by radiotherapy of benign diseases at various body sites, including heterotopic ossification, omarthritis, gonarthrosis, heel spurs and hidradenitis suppurativa.

Material and methods: The carcinogenic risk is estimated by applying the effective dose concept from the ICRP with the average risk factor of 10% per Sv for high dose and high dose rate. Although, the concept of effective dose for the present study has limitations, its use is considered acceptable for a fairly rough risk estimate. The organ doses are calculated using a Monte Carlo radiation transport code and anthropomorphic mathematical phantoms. Special risk modifying factors like patient's age at exposure and gender are taken into account.

Results: For the treatment of heterotopic ossification, omarthritis, gonarthrosis, heel spurs and hidradenitis suppurativa the effective dose is in the range of 5-400 mSv. For an average-aged population, the estimated number of radiation-induced fatal tumours due to these treatments is assessed to be between 0.5 and 40 persons per 1000 patients treated. At higher ages the risks are reduced.

Conclusions: The range of effective doses found for the various types of treatment at various body sites is large. There are several possibilities to optimise the treatment protocols resulting in reduced effective doses and related radiation risks.