How to Report PSMA PET - Beyond the Abstract

Optimal management of patients with prostate cancer (PCa) poses a significant challenge for global healthcare systems. PSMA-PET/CT is endorsed by multiple guidelines for diverse prostate cancer indications. However, the need for unified reporting methods to convey PSMA-PET/CT results to referring physicians and facilitate treatment decisions across different disease stages is paramount.

This review aims to serve as a valuable resource for nuclear medicine practitioners in PSMA-PET/CT reporting.

The review discusses the Prostate-Specific Membrane Antigen (PSMA) molecule and the impact of the different peptides on the biodistribution and diagnostic findings on PSMA-PET. It highlights specificity and positive predictive value as key diagnostic strengths of PSMA-PET, and the value of including preclinical risk in assigning significance of scan findings in report conclusions.1

The review gives an overview of the evidence for PSMA-PET in both PCa staging and biochemical recurrence (BCR). Most guidelines recommend PSMA-PET for staging intermediate- and high-risk patients being considered for definitive therapy and in BCR if PSA > 0.2-0.5 ng/mL.2,3 PSMA-PET is a cornerstone for assessment of patient eligibility for PSMA radioligand therapy (RLT). The review discusses the different criteria utilised to define eligibility and highlighted the role of whole body SUVmean as a positive predictor for patients’ outcomes with 177Lu-PSMA therapy. It also discusses the growing body of literature on the qualitative and quantitative criteria of post-therapy PSMA-PET and 177Lu-PSMA-SPECT in assessment of response to 177Lu-PSMA.

Standardized and synoptic reporting are also explained, particularly published frameworks for detailing PSMA-PET findings, with a specific focus on PROMISE version 2, PRIMARY, PSMA_RADS, and E-PSMA. An illustrative example of PSMA-PET in staging a patient with metastatic prostate cancer is provided with the synoptic report example incorporating the previous criteria (Figure 1 and 2).


Figure 1. PSMA-PET/CT for initial staging of a 75-year-old man with metastatic prostate cancer. MIP (A), axial images (a- d) showing bilateral prostate lesions, right internal iliac and left common iliac nodal lesions and right ischial lytic lesion, respectively. Synoptic report is provided in Fig. 2.


Figure 2. Example of a synoptic report for the staging PSMA-PET/CT provided in Fig. 1.

Pitfalls in PSMA PET reporting are discussed with examples including recognizing benign PSMA-PET findings and refining acquisition protocols to bolster image diagnostic quality.

Written by: Mina Swiha MD, PhD1,2, Narjess Ayati MD1,3,4, Daniela Oprea Lager MD, PhD5, Francesco Ceci MD, PhD6,7, Louise Emmett MBChB, MD1,3,4

  1. Department of Theranostics and Nuclear Medicine, St Vincent’s Hospital, Sydney, Australia
  2. Nuclear Medicine Division, Department of Medical Imaging, University of Western Ontario, London, Canada
  3. St Vincent’s Clinical School, University of New South Wales, Sydney, Australia
  4. Garvan Institute of Medical Research, Sydney, Australia
  5. Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, VU University. Medical Center, Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
  6. Division of Nuclear Medicine, IEO European Institute of Oncology IRCCS, Milan, Italy
  7. Department of Oncology and Hemato-Oncology, University of Milan, Italy

References:

  1. Yaxley JW, Raveenthiran S, Nouhaud FX, et al: Risk of metastatic disease on 68 gallium-prostate-specific membrane antigen positron emission tomography/computed tomography scan for primary staging of 1253 men at the diagnosis of prostate cancer [published correction appears in BJU Int. 2020 Mar;125(3):476]. BJU Int 124(3):401-407, 2019.
  2. Hofman MS, Lawrentschuk N, Francis RJ, et al: Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent surgery or radiotherapy (proPSMA): a prospective, randomised, multicentre study. Lancet 395(10231):1208-1216, 2020.
  3. Gillessen S, Bossi A, Davis ID, et al: Management of Patients with Advanced Prostate Cancer. Part I: Intermediate-/High-risk and Locally Advanced Disease, Biochemical Relapse, and Side Effects of Hormonal Treatment: Report of the Advanced Prostate Cancer Consensus Conference 2022. Eur Urol 83(3):267-293, 2023.
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