Total body photography for the diagnosis of cutaneous melanoma in adults: a systematic review and meta-analysis

Background Early detection of melanoma is essential to reduce mortality. Total body photography (TBP) can facilitate the detection of melanoma in high-risk individuals. However, the accuracy of TBP in diagnosing melanoma remains unclear. Objectives To determine the diagnostic accuracy of TBP for the detection of melanoma in adults. Methods MEDLINE, Embase, Cochrane and Centre for Reviews databases were searched from inception to 26 May 2020. Studies that included TBP for diagnosing melanoma with at least one follow-up appointment were eligible for inclusion in the systematic review if they provided data to calculate at least one diagnostic accuracy measure. Two authors independently screened articles, extracted data and assessed quality. Disagreements were resolved by a third reviewer. Results In total, 10 studies were included, comprising 41 703 patients who underwent TBP and 6203 biopsies. Melanoma in situ (MIS) was diagnosed in 315 (5.1%) lesions and invasive melanoma was diagnosed in 187 (3.0%) lesions biopsied. Summary estimates for TBP in diagnosing melanoma were calculated as follows: mean percentage of biopsies positive for MIS or melanoma was 15% [95% confidence interval (CI) 10-21], number needed to biopsy (NNB) was 8.6 (range 2.3-19.6), naevus : melanoma ratio was 7.6 (range 1.3-18.6), and MIS : melanoma ratio was 1.7 (1.0-3.5). Regression analysis showed a negative correlation between NNB and MIS : melanoma ratio. Conclusions Available data regarding the diagnostic accuracy of TBP are heterogeneous, owing to variability in the risk profile of cohorts and TBP protocols. Best current estimates suggest that TBP for diagnosing melanoma has an acceptable NNB in high-risk patients. However, prospective diagnostic test accuracy studies are needed to gauge the diagnostic accuracy of TBP.