Intra- and interobserver agreement of SUV SPECT® quantitative SPECT/CT processing software, applied in clinical settings for patients with solid renal tumours.

Quantification tools for SPECT/CT are a field of ongoing research among hybrid imaging techniques. A recent multicenter study evaluating SUV SPECT software on phantoms showed that quantitative SPECT/CT is reproducible in Hybrid Viewer software. The aim of our study was to evaluate the intra- and interobserver agreement of quantitative SUV SPECT measurements in clinical settings for patients with solid renal tumors. Methods: The evaluation was part of a study that examined the role of (99)mTc-sestamibi SPECT/CT in the characterization of solid kidney tumors and the differentiation of renal oncocytomas from renal cell carcinomas. Quantitative evaluation of SUV measurements was performed in Hybrid Viewer PDR, version 2.5. Forty-eight renal lesions were identified and examined twice by 2 independent readers. The agreement of the SUV measurements, concerning renal tumors and adjacent renal parenchyma, was evaluated using the intraclass correlation coefficient (ICC). Results: ICC for SUVmax measurements by the same reader was 97%-99% for solid renal tumors and 92%98% for ipsilateral healthy renal parenchyma. ICC for SUVmax measurements between readers was 87%-89% for solid renal tumors and 72%-73% for ipsilateral healthy renal parenchyma. Estimated ICC for SUVmean measurements of solid renal tumors was 95%-98% for the same reader and 86%-89% between readers. Similar results were found for SUVpeak measurements. Conclusion: The high ICCs indicate a strong agreement among SUV measurements for patients with solid renal lesions undergoing (99)mTc-sestamibi SPECT/CT, not only for measurements by the same reader but also for measurements between 2 different readers.