241. Radiation risk due to medical imaging in long living patients: the case of Hodgkin lymphoma

Abstract

Purpose Serious concern were risen in the scientific community on the risk of second cancer due to medical imaging in long-living cohort of patients with advanced stage Hodgkin Lymphoma (HL). The purpose of this work was to analyze a cohort of patient enrolled in a clinical trial to understand the type and number of medical examination performed by the patients and estimate the cumulative effective dose. Methods We used ZeroDose, an automatic home-made tool for the effective dose calculation from DICOM images to analyze a population of 29 HL patients prospectively enrolled in HD0607 clinical trial. The patients performed examination for staging, interim re-staging after two courses of chemo-therapy, end-of-therapy re-staging and several follow-up examinations. Results Average number of exams per patient was 10.9, 2.2, 4.2, 1.4 and 3.0 for total, staging, interim, end of therapy and follow-up, respectively. The average effective dose was 64, 18, 18, 12 and 16 mSv for total, staging, interim, end of therapy and follow-up, respectively. 93% and 100% of patients performed a PET-CT for staging and interim re-staging. The average dose during therapy was of 47 mSv. The number of patients exposed to an effective dose per patient/year in the range 20–50 mSv was 58.6%, 24.2% in the range 50–100 mSv, and 7% for more than 100 mSv; only 3 patients had a low exposure Conclusions The effective doses to patients in this investigation was smaller than the ones reported in literature. Results show an intensive, not always necessary, radiological follow-up suggesting a more stringent adoption of guidelines in clinical practice. Optimization based not only on the characteristics of the patient (age, sex, and body habitus) but also on therapeutic stage will be endeavoured in the future.