The clinical consequences of routine ⁶⁸Ga-PSMA-11 PET/CT in patients with newly diagnosed prostate cancer, ISUP grade 5 and no metastases based on standard imaging – preliminary results

Abstract

Aim

To evaluate the clinical consequences of prostate specific membrane antigen (PSMA) PET/CT for primary staging in patients with ISUP grade 5 (Gleason score ≥9) prostate cancer (PCa), and no definitive distant metastases based on standard imaging.

Methods

At our tertial referral center, PSMA PET/CT became standard of care from August 2018 for primary staging of prostate cancer given the following criteria: (1) no prior treatment for prostate cancer, (2) ISUP grade 5, (3) no definitive metastases on standard imaging (contrast enhanced CT and bone scintigraphy), and (4) deemed suitable for treatment with curative intent based on comorbidity and life expectancy. We present the preliminary results of first six months recruitment with 12 months of follow-up.

Results

Forty-eight patients (mean age 69 years, median PSA 13.0 ng/mL, 20 patients with locally advanced PCa) were included. CT was positive in pelvic lymph nodes in two patients, bone scintigraphy was equivocal in three patients. PSMA PET/CT showed pathological uptake outside the prostatic bed in 22 patients (46%) of which 13 patients (27%) showed lesions confined to regional lymph nodes, and nine patients (19%) showed nonregional lymph node metastases and/or bone metastases. PSMA PET/CT changed the treatment strategy from curatively intended treatment to palliative treatment in 18 patients (38%)

Conclusion

PMSA PET/CT revealed pathological uptake in a large proportion of high-risk patients at primary staging among patients with no definite metastases on standard imaging leading to change of patient management in 38% of the patients.

Keywords:

• 68Ga-PSMA PET/CT
• prostate cancer
• primary staging
• change of patient management

Acknowledgements

Anja M Laursen and Niels Harving, Department of Urology, Aalborg University Hospital and Mette Moe, Department of Oncology, Aalborg University Hospital are thanked for their clinical contribution to the present paper.

Author contributions

HD Zacho participated in designing the study, data collection, analysis and writing first draft of the manuscript. S Nalliah participated in data collection, analysis and critical revision of the manuscript. A Petersen participated in data collection and critical revision of the manuscript and LJ Petersen participated in design of the study, analysis, and critical revision of the manuscript. All authors approved of the final version of the manuscript prior to submission.

Disclosure statement

No potential conflict of interest was reported by the author(s).