The accurate detection of nodal invasion is an unmet need in the clinical staging of renal cancer. Positron emission tomography (PET) with 18F-fluoroazomycin arabinoside (18F-FAZA), a hypoxia specific tracer, is a non-invasive imaging method that detects tumour hypoxia. The aim of this work was to evaluate the role of 18F-FAZA PET/CT in the identification of lymph node metastases in renal cancer.
A proof-of-concept phase 2 study including 20 kidney cancer patients ( ClinicalTrials.gov Identifier: NCT03955393) was conducted. Inclusion criteria were one or more of the following three criteria: (1) clinical tumour size > 10 cm, (2) evidence of clinical lymphadenopathies at preoperative CT scan and (3) clinical T4 cancer. Before surgery, 18F-FAZA PET/CT was performed, 2 h after the intravenous injection of the radiotracer. An experienced nuclear medicine physician, aware of patient's history and of all available diagnostic imaging, performed a qualitative and semi-quantitative analysis on 18F-FAZA images. Histopathological analysis was obtained in all patients on surgical specimen.
Fourteen/19 (74%) patients had a non-organ confined renal cell carcinoma (RCC) at final pathology (either pT3 or pT4). Median number of nodes removed was 12 (IQR 7-15). The rate of lymph node invasion was 16%. No patient with pN1 disease showed positive 18F-FAZA PET, thus suggesting the non-hypoxic behaviour of the lesions. In addition, neither primary tumour nor distant metastases presented a pathological 18F-FAZA uptake. No adverse events were recorded during the study.
18F-FAZA PET/CT scan did not detect RCC lymph neither nodal nor distant metastases and did not show any uptake in the primary renal tumour.
European journal of nuclear medicine and molecular imaging. 2020 Jul 08 [Epub ahead of print]
Umberto Capitanio, Gino Pepe, Elena Incerti, Alessandro Larcher, Francesco Trevisani, Roberta Lucianò, Paola Mapelli, Valentino Bettinardi, Cristina Monterisi, Andrea Necchi, Stefano Cascinu, Rosa Bernardi, Roberto Bertini, Claudio Doglioni, Luigi Gianolli, Andrea Salonia, Maria Picchio, Francesco Montorsi
Unit of Urology, Division of Experimental Oncology, Urological Research Institute (URI), IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy. ., Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy., Unit of Urology, Division of Experimental Oncology, Urological Research Institute (URI), IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy., Unit of Pathology, IRCCS San Raffaele Scientific Institute, Milan, Italy., Unit of Oncology, IRCCS Istituto dei Tumori, Milan, Italy., School of Medicine, Vita-Salute San Raffaele University, Milan, Italy., Division of Experimental Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy.