Abnormal Biologic Distribution Related to Normal Saline Among ^99mTc-Dimercaptosuccinic Acid Scans

The primary aim was to describe the incidence and causes of abnormal distribution of ^99mTc-dimercaptosuccinic acid (^99mTc-DMSA) among patients who underwent renal scans in Royal Hospital (Oman) in 2020. The secondary aim was to assess the effect of a specific batch of normal saline A (batch 132129) compared with another normal saline, B (batches 132589 and 133325), used in the preparation of ^99mTc-DMSA on the abnormal biodistribution of ^99mTc-DMSA. Methods: This was an ambidirectional cohort study that included all patients who underwent ^99mTc-DMSA renal scanning between January and December 2020. Both prospective and retrospective data collection was used. The collected data included possible causes of abnormal biodistribution, quality of ^99mTc-DMSA and normal saline, and time of ^99mTc-DMSA injection. Results: The total incidence of abnormal biodistribution was 26.5%, with the most common cause being a high creatinine level (29%). Normal saline batch A was significantly associated with abnormal biodistribution (49.7%), compared with batch B (6.6%) (P < 0.001). This association was more prominent among patients injected with the ^99mTc-DMSA preparation after 2 h (83.0%) compared with before 2 h (13.3%). Conclusion: A high incidence of abnormal biodistribution of ^99mTc-DMSA was detected and-for what is the first time, to our knowledge, in the literature-a specific preservative-free, normal saline that is up to standard has been identified as a significant cause of abnormal biodistribution. Nuclear medicine professionals and pharmaceutical companies should take note of this possible cause of abnormal ^99mTc-DMSA biodistribution.