Nuclear medicine procedure volume and estimation of collective effective dose in Tamil Nadu towards the establishment of diagnostic reference level

With an objective to establish adult diagnostic reference levels in the practice of nuclear medicine (NM) in the state of Tamil Nadu (TN), data on the predominant NM procedures carried out in the state are analyzed. In this study, data on total NM diagnostic procedures during the years 2015-19 along with patient-specific diagnostic NM procedure data for the period April-June 2021 from all centers in Tamil Nadu are collected and analyzed using SPSS statistical software. Nine predominant types of NM scans are analyzed. Collective effective dose from NM scans and per capita dose for the TN population are estimated. The 75. percentile of the distribution and average administered activity (AAA) has been derived and local reference levels are reported. Based on the statistical analysis, it is observed that the whole-body positron emission tomography (PET), renal diethylenetriamine pentaacetate (DTPA) scan, bone methylene diphosphonate (MDP) scan, iodine-131 whole body scan, thyroid studies using Technetium per technetate, renal dimercaptosuccinic acid (DMSA), myocardial perfusion methoxy-isobutyl isonitrile sestamibi (MIBI), mebrofenin, Gallium-68 prostate-specific membrane antigen (PSMA) are the most common procedure covering >90% of the practices carried out. The collective effective dose is 410 man-Sv in the year 2019, leading to a mean effective dose of 0.006 mSv per capita of the TN state population. The 75. percentile of the distribution of AA is slightly higher than diagnostic reference level (DRL) as compared with Australian DRL (310 MBq). It is also observed that F-18 PET procedures are primarily responsible for most of the collective effective dose, local DRL is 316 MBq and it is important to establish national DRLs for NM diagnostic scans to optimize the NM examinations. (authors)