A study supported by Blue Earth Diagnostics showed that physicians can be trained to successfully interpret Axumin PET scan images of patients with suspected recurrence of prostate cancer.
Axumin is the first F-18 PET imaging agent approved for use in men with suspected recurrent prostate cancer, based on increased blood levels of PSA following treatment.
The Phase 3 study (NCT02680041) was designed to train readers without any experience in reading Axumin PET/CT images to interpret images from patients with recurrent prostate cancer with acceptable diagnostic performance and reproducibility.
It next assessed the ability of readers to accurately interpret Axumin images and compared it to reader concordance in other data, such as biopsies and clinical follow-up. The study included 121 images from 110 patients.
Readers were trained to conduct image analysis at several levels, including lesion, prostate region, images from other regions (bone or soft tissue metastases, for instance), and patient. The study also analyzed whether the training protocol would help different readers reach the same results.
The study found the overall ability of the readers to classify Axumin uptake as malignant had a Positive Predictive Value (PPV) of 71 percent (98/139) when looking at lesion images, 73 percent (53/73) for prostate region images, 92 percent (24/26) for images of other regions, and 79 percent (68/86) at patient level.
Overall sensitivity was 92 percent (68/74) at the patient level, 91 percent (53/58) for the prostate region, 86 percent (24/28) for other regions, and 64 percent at the lesion level, it found. Also, the three different readers showed comparable accuracy during the interpretation of Axumin images.
Together, these results showed that a standardized protocol for the interpretation of Axumin images helps readers achieve acceptable diagnostic performance and reproducibility when staging recurrent prostate cancer.
“Commonly used imaging techniques for the identification of suspected recurrent prostate cancer are limited in the information they provide, leaving physicians with difficult medical challenges in defining appropriate care for their patients,” Dr. Lale Kostakoglu, the study’s author, said in a news release. “This study demonstrated that Axumin reader training enabled overall consistent image interpretation at the patient level and for regional sites of recurrence. In my experience, PET/CT imaging with Axumin effectively detects and localizes recurrent disease, which can help guide my patient management decisions.”