This is the final report covering the work performed under an interagency agreement between the National Bureau of Standards and the Bureau of Radiological Health during the fiscal years 1978 and 1979. A thermoluminescence dosimetry system suited for a survey of high - energy bremsstrahlung in U. S. radiation - therapy departments was selected and calibrated . The experiments leading to the choice of the recommended operational characteristics , including dosimeter handling , annealing and readout , dosimeter stability in the contemplated mode of operation , dosimeter response over the photon - energy range to be covered , irradiation geometry and irradiation level are treated in detail . Results are reported of a pilot study involving the shipment of a typical survey assembly (a plastic phantom loaded with a set of dosimeters) for irradiation in one U. S. therapy department and the overall uncertainty of the proposed survey procedure is discussed.