The Accuracy of 68Ga-PSMA PET/CT in Primary Lymph Node Staging in high-risk Prostate Cancer

PURPOSE:

To assess the diagnostic accuracy of 68Ga-PSMA PET in predicting lymph node (LN) metastases in primary N staging in high-risk and very high-risk nonmetastatic prostate cancer in comparison with morphological imaging.

METHODS:

This was a multicentre trial of the Society of Urologic Oncology in Turkey in conjunction with the Nuclear Medicine Department of Cerrahpasa School of Medicine, Istanbul University. Patients were accrued from eight centres. Patients with high-risk and very high-risk disease scheduled to undergo surgical treatment with extended LN dissection between July 2014 and October 2015 were included. Either MRI or CT was used for morphological imaging. PSMA PET/CT was performed and evaluated at a single centre. Sensitivity, specificity and accuracy were calculated for the detection of lymphatic metastases by PSMA PET/CT and morphological imaging. Kappa values were calculated to evaluate the correlation between the numbers of LN metastases detected by PSMA PET/CT and by histopathology.

RESULTS:

Data on 51 eligible patients are presented. The sensitivity, specificity and accuracy of PSMA PET in detecting LN metastases in the primary setting were 53%, 86% and 76%, and increased to 67%, 88% and 81% in the subgroup with of patients with ≥15 LN removed. Kappa values for the correlation between imaging and pathology were 0.41 for PSMA PET and 0.18 for morphological imaging.

CONCLUSIONS:

PSMA PET/CT is superior to morphological imaging for the detection of metastatic LNs in patients with primary prostate cancer. Surgical dissection remains the gold standard for precise lymphatic staging.

Eur J Nucl Med Mol Imaging. 2017 Jun 18. doi: 10.1007/s00259-017-3752-y. [Epub ahead of print]

Öbek C1, Doğanca T2, Demirci E3, Ocak M4, Kural AR5, Yıldırım A6, Yücetaş U7, Demirdağ Ç8, Erdoğan SM9, Kabasakal L10; Members of Urooncology Association, Turkey.

Author information

1Department of Urology, Acibadem Taksim Hospital, Inonu Mah., Nizamiye Cad. No:1, 34373 Sisli, Istanbul, Turkey.
2Department of Urology, Acibadem Taksim Hospital, Inonu Mah., Nizamiye Cad. No:1, 34373 Sisli, Istanbul, Turkey.
3Department of Nuclear Medicine, Sisli Etfal Training and Research Hospital, Istanbul, Turkey.
4Faculty of Pharmacy, Department of Pharmaceutical Technology, Istanbul University, Istanbul, Turkey.
5Department of Urology, Acibadem University, Istanbul, Turkey.
6Department of Urology, Istanbul Medeniyet University, Istanbul, Turkey.
7Department of Urology, Istanbul Training and Research Hospital, Istanbul, Turkey.
8Department of Urology, Istanbul University, Cerrahpasa School of Medicine, Istanbul, Turkey.
9Department of Public Health, Istanbul University, Cerrahpasa School of Medicine, Istanbul, Turkey.
10Department of Nuclear Medicine, Istanbul University, Cerrahpasa School of Medicine, Istanbul, Turkey.