The two most recently approved molecular imaging agents in the United states, namely F-18 fluciclovine and Ga-68 DOTATATE, were primarily studied in single center, investigator-sponsored trials.  Investigators at these institutions developed a reading methodology, learning through experience how to identify true positive and false positive lesions, incidental findings and normal physiologic uptake.  While this information is shared within an institution, this knowledge is rarely extended outside the institution.  Developing a consensus among readers experienced in image interpretation is a key step in developing agent-specific training for new readers. The Clinical Trials Network (CTN) has done this for fluciclovine and DOTATATE, with DOTATOC and PSMA in development.

It is accepted that consistent and accurate inter- and intra-reader evaluations of research PET images are crucial to the success of a clinical trial.  Further, disappointing results with a new imaging agent because of poor patient selection, unoptimized dosing, scanning or reconstruction, will hamper the adoption of the agent.  CTN has developed radiopharmaceutical-specific online accessible educational modules consisting of imaging agent information, and carefully selected image training sets with common biodistributions, false-positive and false-negative findings, and a post-training self-assessment test that have been demonstrated to be an effective means of training agent-naïve physicians.  The methodology was tested by having experienced nuclear medicine physicians self-administer the slide-based training interpreting 10 test cases.  For Fluciclovine, all readers correctly identified the presence or absence of suspicious lesions in 90% or more of 30 regions (prostate, lymph nodes, and bone) across the 10 patients. Similar results were achieved with the Ga-68 DOTATATE module.

Prospectively, reader training is being developed for Ga-68 PSMA and DOTATOC trials ongoing in the US to ensure that all study investigators and blinded readers interpret the images consistently and accurately.  These efforts are viewed positively by regulators.