Dose distribution throughout the body from radiotherapy for Hodgkin's disease in childhood

Background and purpose: The individual dosimetry performed for a multicentr e European cohort study of second malignant neoplasm following radiotherapy for a solid cancer in childhood demonstrated a large variation in the radi ation doses estimated to any site. Materials and methods: From this study we have extracted the present work, i.e. estimation of doses for patients who underwent radiotherapy for Hodgki n's disease in their childhood. These patients were treated using high ener gy X-rays from linear accelerators (MV group), gamma-radiation from Cobalt machines (Cobalt group), soft X-rays from orthovoltage machines (kV group) and electron beams from accelerators (MeV group) at six French and UK centr es. All patients started their radiotherapy between 1955 and 1985 and about 12% of them received more than one beam quality. Most of the patients were irradiated with large mantle AP/PA or partial mantle fields. Patients with transdiaphragmatic extension were also irradiated using inverted-Y paraaor tic fields. The absorbed doses at the 91 skeleton points are used to calcul ate the mean dose to the active bone marrow. Results: Estimates of the median and mean doses, standard deviations and ra nges to 13 specific sites of the body and to the active bone marrow are rep orted. Depending upon the size and sex of patients, target volume and posit ion and radiotherapy techniques, the estimated doses are highly spread, att aining 0.19-106.07% of the target dose. This study underscores the need for individual dosimetry in epidemiological studies. Comparison with the avail able measured and calculated doses to the ovary and testis shows good agree ment. Conclusion: This study underscores the need for individual dosimetry in epi demiological studies. (C) 1998 Elsevier Science Ireland Ltd. All rights res erved.