Phase 2 trial of PSMA PET CT versus planar bone scan and CT in prostate cancer patients progressing while on androgen deprivation therapy

• Published in: Scientific reports Vol. 14; no. 1; pp. 24411 - 8
• Main Authors: Nikitas, John, Gafita, Andrei, Benz, Matthias R., Djaïleb, Loïc, Farolfi, Andrea, Hotta, Masatoshi, Sonni, Ida, Alano, Rejah, Rettig, Matthew, Shen, John, Armstrong, Wesley, Grogan, Tristan, Liu, Sandy, Czernin, Johannes, Calais, Jeremie
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.10.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/67/1344; 631/67/589/466; 692/308/2779/109; 692/4028/67/2321; 692/700/1421/1771; 692/700/1421/2109; 692/700/1421/2770; Aged; Aged, 80 and over; Androgen Antagonists - therapeutic use; Androgen deprivation therapy; Androgens; Antigens; Antigens, Surface - metabolism; Biochemical recurrence; Bone and Bones - diagnostic imaging; Bone and Bones - drug effects; Bone and Bones - metabolism; Bone and Bones - pathology; Bone cancer; Bone imaging; Bone lesions; Bone metastases; Bone Neoplasms - diagnostic imaging; Bone Neoplasms - drug therapy; Bone Neoplasms - secondary; Bone scan; Computed tomography; Disease Progression; Gallium Isotopes; Gallium Radioisotopes; Glutamate Carboxypeptidase II - metabolism; Humanities and Social Sciences; Humans; Lesions; Male; Metastases; Metastasis; Middle Aged; multidisciplinary; Patients; Positron emission tomography; Positron Emission Tomography Computed Tomography - methods; Prospective Studies; Prostate cancer; Prostate-specific antigen; Prostate-Specific Antigen - blood; Prostate-specific membrane antigen PET/CT; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - drug therapy; Prostatic Neoplasms - pathology; Radioactive tracers; Radiopharmaceuticals; Science; Science (multidisciplinary); Scintigraphy; Tomography; Tomography, X-Ray Computed - methods; Prostate-specific membrane antigen PET/CT; Androgen deprivation therapy; Biochemical recurrence; Bone metastases; Bone scan
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-75589-6

For prostate cancer patients who experience biochemical progression during androgen deprivation therapy (ADT), prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) has not been prospectively compared to planar bone scan plus CT. This was a single-arm, head-to-head, prospective phase II trial (NCT04928820) designed to enroll 102 men with prostate cancer who experienced biochemical progression (rising prostate-specific antigen [PSA] ≥ 1 ng/mL) during ADT. All patients received 68Ga-PSMA-11 PET/CT and 99mTc-MDP planar bone scans. Each scan was interpreted by three central independent readers. The primary endpoint was the per-patient bone metastasis detection rate of PSMA PET/CT versus planar bone scan and CT. Secondary endpoints compared the number of bone metastases detected per patient and the inter-reader agreement of each imaging modality. Twenty-two men were enrolled between July 2021 and June 2022. Due to slow accrual following approval of PSMA PET radiotracers in the U.S. and a lack of a statistical signal between the two imaging modalities on interim analysis, this trial was closed early on October 2022. Median PSA was 8.5 ng/mL (interquartile range: 1.6–77.6). There was 100% agreement between the two scans. Six patients (27%) had negative findings and 16 patients (73%) had positive findings on both scans. PSMA PET/CT and bone scan plus CT detected an equal number of bone lesions for 14 patients (64%), PSMA PET/CT detected more bone lesions for six patients (27%), and bone scan plus CT detected more bone lesions for two patients (9.1%) (p = 0.092). The inter-reader agreement rates of PSMA PET/CT and bone scan plus CT were 96% and 82%, respectively ( p  = 0.25). In men with biochemical progression during ADT, 68Ga-PSMA-11 PET/CT and 99mTc-MDP planar bone scan plus CT had identical bone metastasis detection rates. Bone scan plus CT can continue to serve as a cost-effective and readily accessible restaging modality in patients with biochemical progression. ClinicalTrials.gov NCT04928820. Registered 16/06/2021.