Prostate-Specific Membrane Antigen PET/CT Combined with Sentinel Node Biopsy for Primary Lymph Node Staging in Prostate Cancer

• Published in: Journal of Nuclear Medicine Vol. 61; no. 4; pp. 540 - 545
• Main Authors: Hinsenveld, Florentien J., Wit, Esther M.K., van Leeuwen, Pim J., Brouwer, Oscar R., Donswijk, Maarten L., Tillier, Corinne N., Vegt, Erik, van Muilekom, Erik, van Oosterom, Matthias N., van Leeuwen, Fijs W.B., van der Poel, Henk G.
• Format: Journal Article
• Language: English
• Published: United States Society of Nuclear Medicine 01.04.2020
• Subjects: Accuracy; Antigens; Biopsy; Cancer surgery; Confidence intervals; Diagnostic systems; Lymph nodes; Lymphatic system; Membranes; Metastases; Metastasis; Positron emission; Positron emission tomography; Prostate cancer; Prostatectomy; Radiation therapy; Robots; Sensitivity; Tomography; Tracers; Urological surgery; image-guided surgery; sentinel node biopsy; PSMA; prostate cancer; lymphatic metastasis
• ISSN: 0161-5505; 1535-5667; 2159-662X; 1535-5667
• DOI: 10.2967/jnumed.119.232199

Our objective was to determine the diagnostic capabilities of combined prostate-specific membrane antigen (PSMA) PET/CT and sentinel node (SN) biopsy in PSMA PET/CT-negative patients for primary lymph node (LN) staging in prostate cancer (PCa) patients. Between January 2017 and March 2019, retrospectively, all consecutive patients with diagnosed intermediate- or high-risk primary PCa who underwent preoperative PSMA PET/CT ( Ga or F-DCFPyL) followed by robot-assisted radical prostatectomy and extended pelvic LN dissection (ePLND) were included. All patients without suspected LN metastases on PSMA PET/CT were considered candidates for SN biopsy with indocyanine green- Tc-nanocolloid or Tc-nanocolloid with free indocyanine green used as tracers. The ePLND was used as a reference standard. Of 53 patients, 22 had positive PSMA PET/CT results and 31 underwent subsequent SN biopsy after negative PSMA PET/CT results. In total, 23 patients (43%) were pN1, of whom 6 (26%) had negative PSMA PET/CT results and underwent subsequent SN biopsy. The combined use of SN biopsy and PSMA PET/CT identified all pN1 patients (100% sensitivity; 95% confidence interval, 86%-100%) and performed correct nodal staging in 50 of 53 patients (94% diagnostic accuracy; 95% confidence interval, 84%-99%). SN biopsy identified significantly smaller LN metastases (median diameter, 2.0 mm; interquartile range, 1.0-3.8 mm) than PSMA PET/CT (median diameter, 5.5 mm; interquartile range, 2.6-9.3 mm; = 0.007). Combining both modalities led to a 94% accuracy for nodal staging in diagnosed intermediate- and high-risk primary PCa. Adding SN biopsy in patients with negative PSMA PET/CT results increased the combined sensitivity to 100% for detecting nodal metastases at ePLND. This diagnostic accuracy may provide valuable information for directing further treatment in PCa patients, such as the use of PSMA PET/CT and SN biopsy rather than ePLND as the preferred approach for staging before radiotherapy.