Evaluating 18F-Flotufolastat in Black Patients With Prostate Cancer Recurrence

Black patients are often under-represented in oncology clinical trials, despite facing a disproportionate risk of prostate cancer.

A post hoc analysis of the SPOTLIGHT study conducted by Soroush Rais-Bahrami, MD, and colleagues published in Advances in Radiation Oncology sought to determine the diagnostic performance of the novel diagnostic positron emission tomography (PET) radiopharmaceutical ¹⁸F-flotufolastat in Black patients.

The SPOTLIGHT trial evaluated ¹⁸F-flotufolastat in patients with recurrent prostate cancer. Participants received PET/computed tomography within 50 to 70 minutes following intravenous administration of ¹⁸F-flotufolastat 296MBq. Images were analyzed by blinded readers, and the standard-of-truth (SoT) was estimated with histopathology or correlative imaging.

Dr. Rais-Bahrami and colleagues noted that in the SPOTLIGHT study, the proportion of Black patients was higher than most oncology trials and representative of the US population.

Of the 61 (17%) Black patients, the patient-level detection rate (DR) was 93%, an increase from 67% at prostate-specific antigen (PSA) <0.5 ng/mL to 100% at PSA ≥10 ng/mL. In other patients, the patient-level DR was slightly lower (87%).

Following stratification by prior treatment in postprostatectomy patients, DR was similar across ethnic groups. However, in patients with intact prostates, Black patients reported increased prostate DR over non-Black patients.

SoT verification completed with conventional imaging reported a verified DR (VDR) of 64% and a positive predictive value (PPV) of 68% in Black patients, compared with 55% and 64%, respectively, in other patients.

“¹⁸F-flotufolastat DRs were marginally higher in [Black patients] than all other patients enrolled in SPOTLIGHT,” researchers wrote. “High VDR and PPV were also achieved in [Black] patients from across all participating centers, indicating the broad applicability of newly [US Food and Drug Administration]-approved ¹⁸F-flotufolastat to the US population as a whole.”