Absorbed doses in the head and oral cavity during total body irradiation

Conditioning before bone marrow transplantation (BMT) with total body irradiation (TBI) and cyclophosphamide carries the risk of severe long-term complications. The aim of the present study was to determine absorbed doses in the craniofacial area during TBI, using thermoluminescent dosimeters for both in vivo techniques and phantom measurements. The results from the phantom study showed that the mean deviation from the reference dose varied between -5.1 and +11.1%. The superficial part of left parotid gland received 11.1 +/- 1.5% more radiation compared with the reference. In patients, deviations from the reference dose varied in individual patients between -22.4 and +20.1% in various intra-oral sites. Since a small increase in dose can result in a significantly increased risk of pathology, the observed dose inhomogeneities for structures receiving tangentially directed radiation therapy, such as the parotid glands, may contribute to salivary dysfunction after TBI.