1/ The #ProPSMA study was recently published in @TheLancet . My first tweetorial follows...

Read the full text at https://authors.elsevier.com/a/1atNZV-4XAjqh 

@Movember @PCFA @gu_onc @declangmurphy @lawrentschuk @SNM_MI @ANZUPtrials

2/ Relapse in men with high-risk prostate cancer (PCa) after surgery or radiotherapy is common.

In part, this relates to failure of current imaging to detect disease spread.

We hypothesised that PSMA PET would dimprove accuracy and can replace current use of CT & bone scan.

3/ PSMA PET/CT is a new scan for imaging PCa. A radiolabelled small molecule binding to prostate specific membrane antigen (PSMA) is given iv. It is taken up into PCa cells. PET scanning then enables 3D whole body specific tumour imaging.

4/ The #proPSMA study brought together enthusiastic nuclear medicine, urology, radiation oncology and clinical trials investigators at 10 sites around Australia. This was an academic trial with no commercial entity involved.

5/ 302 men with high-risk prostate cancer were randomised to standard imaging (CT + bone scan with SPECT/CT) or PSMA PET/CT. High-risk disease was defined by:
Gleason grade group 3-5
PSA ≥ 20
Clinical T stage ≥ 3

Men with <3 distant metastases, crossed over to the other arm.

6/ The “ground truth” is always difficult to define.

Most think it is histopathology but it isn’t possible to biopsy all sites, and biopsy subject to sampling error.

We used pathology, changes in imaging and biochemistry, up to 6 months post randomisation to define "truth"

7/ Main finding: PSMA PET/CT was 27% more accurate than conventional imaging (92% vs 65%).

This was also true for nodal and distant metastatic subgroups.

And for a sensitivity analysis if equivocal lesions were considered +ve.

8/ Here is the distribution of PSMA PET/CT findings.

Lot's of other intesting in the Supplementary Appendix, available online!

9/ Secondary endpoints showed higher management change with PSMA PET, less equivocal studies, lower radiation exposure and high reporter agreement for PSMA PET.

All important outcome measures for patients.

10/ We conclude that PSMA PET/CT imaging is a suitable replacement for current standard-of-care CT and bone scan. This infographic summarises the study.

11/ Want to learn more, dive deeper? Join our @PCF_Science Global Journal Club

15 Apr 1PM PT | 4PM ET | 9PM London | 10PM Berlin | 16 Apr 6AM Melbourne

Register http://bit.ly/propsma-webinar 

Gratitude to @MovemberAUS @PCFA for funding
ARTnet @ANZUPtrials Patients & Investigators