Baseline 18F-Fluorocholine PET/CT and bone scan in the outcome prediction of patients treated with radium 223 dichloride

To establish the utility of baseline 18F-Fluorocholine (FCH) PET/CT and bone scintigraphy (BS) in the outcome prediction of patients with castration-resistant prostate cancer and bone metastases (CRPC-BM) treated with 223Ra.

Prospective, multicenter and non-randomized study (ChoPET-Rad study). FCH PET/CT and BS were performed before the initiation of 223Ra (basal FCH PET/CT and BS). Bone disease was classified attending the number of lesions in baseline BS and PET/CT. FCH PET/CT was semiquantitatively evaluated. Gleason score, baseline levels of prostate-specific antigen (PSA), alkaline phosphatase and lactate dehydrogenase were determined. Progression-free survival (PFS) and overall survival (OS) since the onset of 223Ra treatment was calculated. PFS was defined by PSA rising. Relations between clinical and imaging variables with PFS and OS were evaluated by Pearson, Mann-Whitney tests and Kapplan-Meier analysis. Univariate and multivariate Cox regression analysis was performed.

Forty patients were evaluated. The median PFS and OS were of 3.0 ± 2.3 and 23.0 ± 4.2 months, respectively. 33 patients progressed and 13 died during the follow-up. The extension of the bone disease by FCH PET/CT (p = 0.011, χ2 = 10.63), BS (p = 0.044, χ2 = 8.04), SUVmax (p = 0.012) and average SUVmax (p = 0.014) were related to OS. No significant association was found for the PFS. ROC analysis revealed significant association of SUVmax, average SUVmax and basal PSA with OS. Only therapeutic failure was associated with OS in the multivariate analysis (HR = 3.6, p = 0.04).

FCH PET/CT and BS had prognostic aim in the prediction of OS. None clinical or imaging variable was able to predict the PFS, probably due to the high rate of progressive disease.

Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico. 2018 Jul 13 [Epub ahead of print]

A M García Vicente, B González García, M Amo-Salas, I García Carbonero, J Cassinello Espinosa, J L Gómez-Aldaraví Gutierrez, L Suarez Hinojosa, Á Soriano Castrejón

Nuclear Medicine Department, University General Hospital, C/Obispo Rafael Torija s/n, 13005, Ciudad Real, Spain. ., Nuclear Medicine Department, University General Hospital, C/Obispo Rafael Torija s/n, 13005, Ciudad Real, Spain., Departamento de Matemáticas, Universidad de Castilla La Mancha, Ciudad Real, Spain., S. Oncología Médica, Complejo Hospitalario de Toledo, Toledo, Spain., S. Oncología Médica, Hospital Universitario de Guadalajara, Guadalajara, Spain., S. Oncología Médica, Hospital Universitario de Albacete, Albacete, Spain., S. Oncología Médica, H. Manzanares, Ciudad Real, Spain.