Comparison of 99mTc-PSMA SPECT/CT and 68Ga-PSMA PET/CT in patients with prostate cancer: a protocol for systematic review and meta-analysis

A wide range of nuclear imaging probes have been developed to address different metabolic processes and cell receptors in prostate cancer patients using positron emission techniques to aid diagnosis, staging, and monitoring for recurrence after treatment. While 68Ga PSMA is a generator-derived PET radiopharmaceutical, SPECT/CT imaging using technetium-99m-labeled PSMA is now available as a suitable alternative. The aim of this study is to compare the pooled sensitivity, specificity, and accuracy of 99mTc-PSMA SPECT/CT and 68Ga-PSMA PET/CT in patients with prostate cancer. A search strategy was developed using text words, MeSH, and entry terms. The following databases will be searched: PubMed, African Journals Online (AJOL), Embase, Google scholar, ResearchGate, Cochrane Library, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. Eligibility criteria include (a) all studies that are published or retrievable in English language, (b) observational studies, and (c) histopathology analysis or clinical and imaging follow-up or comparison with reference standards. Exclusion criteria will be interventional studies, editorials, reviews, and commentaries. Quality of the studies will be assessed using QUADAS2 Quality scores and risk of bias for individual studies will be reported. Full text of the studies will be reviewed and snowballed for any relevant literature. Assessment of methodological, clinical, and statistical heterogeneity for all the included studies will be made. Publication bias will be assessed using funnel plots. Statistical analysis and forest plots will be performed using the Open Meta-analyst software. The systematic review and meta-analysis will be reported according to PRISMA 2015 Statement. This review will provide data on diagnostic accuracy of 99mTc-PSMA SPECT/CT and 68Ga-PSMA PET/CT in patients with prostate cancer. Results from this study will help nuclear medicine service providers to make better decisions on the appropriate use of 99mTc-PSMA SPECT/CT and 68Ga-PSMA PET/CT especially with regard to the use of 99mTc-PSMA SPECT/CT which is relatively affordable and more readily available in developing countries when compared to 68-Ga PSMA PECT/CT.