Mailed thermoluminescent dosimetry reviews in radiation therapy.

The six Centers for Radiological Physics performed periodic thermoluminescent dosimetry (TLD) reviews for photon beams at 276 facilities across the country. The purpose of the reviews and the techniques in use are briefly described. Results from 2413 mailed reviews of megavoltage units indicate that, in 92% of the reviews, a specified dose was delivered within +/- 5% of the TLD-measured dose.

Backscatter factors in the mammographic energy range.

Backscatter factors for kVps and half-value layers typical of mammographic beams have been determined as a function of beam diameter and half-value layer. The method utilized thin TLD-100 chips with the scattering medium alternately present and absent. Results indicate that the field-size dependence of the backscatter factor for lower half-value layers is less than that shown in the British Journal of Radiology Supplement 11.