Interobserver agreement for the standardized reporting system PSMA-RADS 1.0 on18F-DCFPYL PET/CT imaging

Rudolf A. Werner, Ralph A. Bundschuh, Lena Bundschuh, Mehrbod S. Javadi, Jeffrey P. Leal, Takahiro Higuchi, Kenneth J. Pienta, Andreas K. Buck, Martin G. Pomper, Michael A. Gorin, Constantin Lapa, Steven P. Rowe

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


Recently, the standardized reporting and data system for prostate-specific membrane antigen (PSMA)–targeted PET imaging studies, termed PSMA-RADS version 1.0, was introduced. We aimed to determine the interobserver agreement for applying PSMA-RADS to imaging interpretation of18F-DCFPyL (2-(3-{1-carboxy-5-[(6-18F-flu-oro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid) PET examinations in a prospective setting mimicking the typical clinical workflow at a prostate cancer referral center. Methods: Four readers (2 experienced readers (ERs, .3 y of PSMA-targeted PET interpretation experience) and 2 inexperienced readers (IRs,,1 y of experience)), who had all read the initial publication on PSMA-RADS 1.0, assessed 5018F-DCFPyL PET/CT studies independently. Per scan, a maximum of 5 target lesions was selected by the observers, and a PSMA-RADS score for every target lesion was recorded. No specific preexisting conditions were placed on the selection of the target lesions, although PSMA-RADS 1.0 suggests that readers focus on the most avid or largest lesions. An overall scan impression based on PSMA-RADS was indicated, and interobserver agreement rates on a target lesion–based, on an organ-based, and on an overall PSMA-RADS score–based level were computed. Results: The number of target lesions identified by each observer was as follows: ER 1, 123; ER 2, 134; IR 1, 123; and IR 2, 120. Among those selected target lesions, 125 were chosen by at least 2 individual observers (all 4 readers selected the same target lesion in 58 of 125 [46.4%] instances, 3 readers in 40 of 125 [32%], and 2 observers in 27 of 125 [21.6%]). The interobserver agreement for PSMA-RADS scoring among identical target lesions was good (intraclass correlation coefficient [ICC] for 4, 3, and 2 identical target lesions, $0.60, respectively). For lymph nodes, an excellent interobserver agreement was derived (ICC, 0.79). The interobserver agreement for an overall scan impression based on PSMA-RADS was also excellent (ICC, 0.84), with a significant difference for ER (ICC, 0.97) vs. IR (ICC, 0.74) (P 5 0.005). Conclusion: PSMA-RADS demonstrated a high concordance rate in this study, even among readers with different levels of experience. This finding suggests that PSMA-RADS can be effectively used for communication with clinicians and can be implemented in the collection of data for large prospective trials.

Original languageEnglish
Pages (from-to)1857-1864
Number of pages8
JournalJournal of Nuclear Medicine
Issue number12
Publication statusPublished - Dec 1 2018
Externally publishedYes


  • F-DCFPyL
  • Interobserver
  • Interreader
  • PSMA
  • Prostate cancer

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Interobserver agreement for the standardized reporting system PSMA-RADS 1.0 on18F-DCFPYL PET/CT imaging'. Together they form a unique fingerprint.

Cite this