Diagnostic reference level: an important tool for reducing radiation doses in adult and pediatric nuclear medicine procedures in Brazil.

Objectives: This study aimed to establish a concise method for determining a diagnostic reference level (DRL) for adult and pediatric nuclear medicine patients on the basis of diagnostic procedures and administered radioisotope as a means of controlling medical exposure.

Methods: A screening was carried out in all Brazilian Nuclear Medicine Service (NMS) establishments to support this study by collecting the average activities administered during adult diagnostic procedures and the rules applied to adjust these according to the patient's age and body mass. Percentile 75 was used in all the activities administered as a means of establishing DRL for adult patients, with additional correction factors for pediatric patients.

Dose calibrator linearity test: (99m)Tc versus (18)F radioisotopes.

Objective: The present study was aimed at evaluating the viability of replacing (18)F with (99m)Tc in dose calibrator linearity testing.

Materials And Methods: The test was performed with sources of (99m)Tc (62 GBq) and (18)F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical (99m)Tc and (18)F sources activities were calculated and subsequently compared.