COMPARISON BETWEEN CONVENTIONAL AND CONFORMAL RADIOTHERAPY TREATMENTS FOR PROSTATE CANCER USING THERMOLUMINESCENT DOSIMETRY

Abstract

In the prostate cancer treatment, the dose prescribed by the medical radio-oncologist depends on the extension of the disease and the threshold dose of the adjacent healthy tissues. In order to achieve an optimal tumoral control in early and locally advanced stages, it is necessary to increase the dose with a low morbidity probability at the vesicle and rectal level. This is achieved through conformal radiotherapy. The Instituto Nacional de Cancerología uses this technique, but two questions arise from the medical-physicists and medical radio-oncologist: In accordance with clinical protocols, the conformal radiotherapy delivers a low dose to the adjacent healthy tissues. What experimental method exists that can prove with certainty the veracity of this affirmation? And, Do the dosimetric simulation systems calculate suitably the dose for each tissue, as recommended by International Atomic Energy Agency quality control programs for ionizer radiation? This paper seeks to answer these questions. Through thermoluminescent dosimetry and the use of a physical simulator, we measured the absorbed dose at the target volume and the adjacent tissues using conformal and conventional radiotherapy. We proved that organs such as the rectum and bladder, receive a minor dose in conformal radiotherapy, hence reducing their morbidity probability. In addition, the readings from the thermoluminescent dosimeters and the doses calculated by the ECLIPSE dosimetric system were compared, concluding that the patient's prescribed dose is effectively delivered as recommended by the quality control programs in radiotherapy.