Clinical utility of FDG PET/CT for primary and recurrent papillary renal cell carcinoma

• Published in: Cancer imaging Vol. 21; no. 1; p. 25
• Main Authors: Hou, Guozhu, Zhao, Dachun, Jiang, Yuanyuan, Zhu, Zhaohui, Huo, Li, Li, Fang, Cheng, Wuying
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 25.02.2021; BioMed Central; BMC
• Subjects: Adult; Age; Aged; Aged, 80 and over; Biopsy; Carcinoma, Renal cell; Carcinoma, Renal Cell - diagnostic imaging; Carcinoma, Renal Cell - pathology; Computed tomography; Development and progression; Diseases; FDG; Female; Fluorodeoxyglucose F18 - therapeutic use; Histochemistry; Histopathology; Humans; Kidney cancer; Kidney Neoplasms - diagnostic imaging; Kidney Neoplasms - pathology; Magnetic resonance imaging; Male; Medical imaging; Medical prognosis; Medical research; Medicine, Experimental; Metastasis; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Papillary; Patients; PET imaging; PET/CT; Physiology; Positron emission; Positron Emission Tomography Computed Tomography - methods; Prognosis; Relapse; Renal cell carcinoma; Retrospective Studies; Sensitivity; Surgery; Survival; Tomography; Tumors; Young Adult; FDG; Papillary; Renal cell carcinoma; PET/CT
• ISSN: 1470-7330; 1740-5025; 1470-7330
• DOI: 10.1186/s40644-021-00393-8

Papillary renal cell carcinoma (RCC) is the second most common subtype of RCC, after clear cell RCC. This study aimed to investigate the usefulness of FDG PET/CT in primary and recurrent papillary RCC, and the role of staging FDG PET/CT in predicting survival. A total of 66 patients with histopathologically confirmed papillary RCC who underwent either staging or restaging FDG PET/CT scans (30 had staging scans only, 28 had restaging scans only, 8 had both) were retrospectively included in this study. The sensitivity and specificity of restaging FDG PET/CT for detecting recurrence were assessed by histopathology and/or clinical follow-up as standard reference. Staging FDG PET/CT scans were performed in 38 patients, of which 31 (81.5%) showed FDG-positive primary renal lesions. The SUVmax of high-grade (WHO grade 3 and 4) papillary RCCs were significantly higher than that of low-grade (WHO grade 1 and 2) tumors (9.44 ± 6.18 vs 4.83 ± 3.19, P = 0.008). The SUVmax was not significantly different between type 1 and type 2 papillary RCCs (5.71 ± 2.88 vs. 6.99 ± 5.57, P = 0.563). Of the 38 patients, 12 developed disease progression during the follow-up period. Patients with primary tumor SUVmax> 5.85 were associated with significantly shorter progression-free survival (PFS) than those with tumor SUVmax≤5.85 (P = 0.005). Restaging FDG PET/CT scans were performed in 36 patients with suspected recurrent papillary RCCs. FDG PET/CT showed a sensitivity and specificity of 100 and 72.7% for detecting recurrent disease. Comparison of PET/CT scans with CT/MRI imaging was available in 23 patients. FDG PET/CT revealed additional findings in 11 patients, mainly including lymph node and bone metastases. FDG PET/CT findings led to change in management in 5.3% (2/38) of patients in the staging setting and 16.7 (6/36) of patients in the restaging setting. FDG PET/CT had a sensitivity of 81.5% for detecting primary papillary RCC, and tumor SUVmax derived from staging FDG PET/CT was a predictor of PFS. In the restaging process of papillary RCC, FDG PET/CT was very effective for detecting recurrent disease.