Journal Article

Clinical impact of PSMA PET/CT in primary prostate cancer compared to conventional nodal and distant staging: a retrospective single center study

Donswijk, Maarten L., van Leeuwen, Pim J., Cheung, Zing, Heijmink, Stijn W. T. P. J., van der Poel, Henk G., Stokkel, Marcel P. M., Vegt, Erik

2020

Overview

Background To evaluate the impact of Gallium-68 [ 68 Ga] labeled prostate specific membrane antigen (PSMA) positron emission tomography (PET)/X-ray computed tomography (CT) compared with conventional imaging on staging and clinical management of men evaluated for primary prostate cancer (PCa). Methods Men with newly diagnosed biopsy-proven PCa who had been staged with a conventional staging protocol including bone scintigraphy (BS) and additionally underwent [ 68 Ga]PSMA PET/CT, were evaluated retrospectively. Imaging findings from BS, magnetic resonance imaging (MRI) and/or CT were categorized regarding locoregional nodal (N) and distant metastasis (M) status as negative, positive or equivocal before and after addition of the information of PET/CT. Also, the imaging-based level of confidence (LoC) in correct assessment of N and M status was scored. Impact of PET/CT on clinical management was evaluated by the percentage of treatment category changes after PET/CT as determined in the multidisciplinary tumour board. Results Sixty-four men with intermediate and high-risk PCa were evaluated. With additional information of PET/CT, N status was upstaged in 23%, and downstaged in 9%. M status was upstaged in 13%, and downstaged in 23%. A net increase in LoC of 20% was noted, mainly regarding M status. Treatment category changed from palliative to curative in 9%, and from curative to palliative in 3%. An undecided treatment plan changed to curative in 14%, as well as to palliative in another 9%. In total, a 36% treatment category change was noted. High negative predictive value of PET/CT for M status was indicated by 27 patients that underwent robot-assisted radical prostatectomy and reached postoperative biochemical disease-free status or had a likely other site of disease recurrence. Conclusions PSMA PET/CT can cause considerable changes in N and M staging, as well as in management compared to conventional staging. Findings of this study support the replacement of BS and CT by PSMA PET/CT in staging primary PCa.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abdomen / Aged / Aged, 80 and over / Androgens / Antigens, Surface / Biomedical and Life Sciences / Biomedicine / Biopsy / Bisphosphonates / Bone Neoplasms - diagnostic imaging / Bone Neoplasms - secondary / cancer imaging / Cancer metastasis / Cancer Research / Cancer surgery / Cancer therapies / CAT scans / Comparative analysis / Computed tomography / Drug dosages / Femoral Neoplasms - diagnostic imaging / Femoral Neoplasms - secondary / Gallium / Gallium Radioisotopes / Glutamate Carboxypeptidase II / Health Promotion and Disease Prevention / Humans / Impact / interventional therapeutics / Lymphatic Metastasis - diagnostic imaging / Lymphatic system / Magnetic resonance imaging / Male / Management / Medicine/Public Health / Metastases / Metastasis / Middle Aged / Neoplasm Grading / Neoplasm Staging - methods / Nuclear medicine / Oncology / Palliative Care / Patients / Physicians / Positron emission tomography / Positron Emission Tomography Computed Tomography - methods / Prostate / Prostate cancer / Prostatectomy / Prostatectomy - methods / Prostatic Neoplasms - diagnostic imaging / Prostatic Neoplasms - pathology / Prostatic Neoplasms - surgery / PSMA / Recurrence (Disease) / Research Article / Retrospective Studies / Robotic Surgical Procedures - methods / Robots / Scintigraphy / Staging / Surgical Oncology / Tumors