Does whole-body bone SPECT/CT provide additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence?

To assess whether whole-body (WB) bone SPECT/CT provides additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence (PC-BR).

Patients referred for a PC-BR and whom benefited from a WB bone SPECT/CT and FCH PET/CT were retrospectively included. Tests were classified as positive, equivocal, or negative for bone metastases. A best valuable comparator (BVC) strategy including imaging and follow-up data was used to determine the metastatic status in the absence of systematic histological evaluation.

Between January 2011 and November 2017, 115 consecutive patients with a PC-BR were evaluated. According to the BVC, 30 patients had bone metastases and 85 patients did not present with bone lesions. The sensitivity, specificity, positive and negative predictive values were respectively 86.7% [69.3-96.2], 98.8% [93.6-100.0], 96.3% [78.7-99.5], and 95.5% [89.4-98.1] for WB bone SPECT/CT and 93.3% [77.9-99.2], 100.0% [95.8-100.0], 100.0 and 97.7% [91.8-99.4] for FCH PET/CT. There was no significant difference in diagnostic accuracy of bone metastases between WB Bone SPECT/CT (AUC 0.824 [0.74-0.90]) and FCH PET/CT (AUC 0.829 [0.75-0.90], p = 0.41).

Despite good performances for the diagnosis of bone metastases in PC-BR, WB bone SPECT/CT does not provide additive diagnostic information over concomitant FCH PET/CT.

Cancer imaging : the official publication of the International Cancer Imaging Society. 2020 Aug 12*** epublish ***

Nicolas de Leiris, Julien Leenhardt, Bastien Boussat, Christopher Montemagno, Alexandre Seiller, Olivier Phan Sy, Julie Roux, Mathieu Laramas, Camille Verry, Carole Iriart, Gaelle Fiard, Jean-Alexandre Long, Jean-Luc Descotes, Jean-Philippe Vuillez, Laurent Riou, Loïc Djaileb

Nuclear Medicine Department, Grenoble Alpes University Hospital, Grenoble, France. ., Nuclear Medicine Department, Grenoble Alpes University Hospital, Grenoble, France., Public Health Department, Grenoble-Alpes University Hospital, Grenoble, France., INSERM, U1039, Radiopharmaceutiques Biocliniques, Grenoble, France., Department of Oncology, Grenoble Alpes University Hospital, Grenoble, France., Department of Radiotherapy, Grenoble Alpes University Hospital, Grenoble, France., Department of Urology and Kidney Transplantation, Grenoble Alpes University Hospital, Grenoble, France.