RESUMO
AIM: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.
Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/radioterapia , Neoplasias de Próstata Resistentes à Castração/diagnóstico por imagem , Neoplasias de Próstata Resistentes à Castração/radioterapia , Rádio (Elemento)/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/secundário , Colina/análogos & derivados , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais , Neoplasias de Próstata Resistentes à Castração/secundário , Radioisótopos/uso terapêutico , CintilografiaRESUMO
PURPOSE: To assess the diagnostic impact of 18F-FDG-PET/CT in patients suspected of paraneoplastic neurological syndrome (PNS) based on our own pre-test risk classification (PRC). METHODS: A multicenter retrospective longitudinal study was conducted from 2006 to 2014. We designed a seven-point scoring system using the clinical syndrome characteristics [classical (CS) and non-classical syndromes (NCS)] and its location (central, peripheral, in the neuromuscular junction or combined), onconeural antibodies and tumor markers. Patients were classified as low (score 0-2), intermediate (3-4) and high (5-7) pre-test risk of PNS. FDG-PET/CT was classified as negative or positive. Final diagnosis according Graus' criteria (definite, possible or no PNS) was established. Relations between clinical and metabolic variables with the final diagnosis were studied. RESULTS: 73 patients were included, with a follow-up time of 33 months. Eleven (15 %) patients were finally diagnosed with neoplasm (8 invasive cancers). Ultimately, 13 (18 %) and 24 (33 %) subjects were diagnosed as definite or possible PNS. All the patients with final diagnosis of neoplasm had a CS (p = 0.005). PET/CT was helpful to diagnose 6/8 (75 %) invasive cancers. PET/CT findings were associated with the final diagnosis of neoplasm (p = 0.003) and the diagnosis of PNS attending to Graus' criteria (p = 0.019). PRC showed significant association with the final diagnosis of neoplasm and PET/CT results. A majority of patients (10/11) diagnosed of neoplasm had intermediate/high-risk. CONCLUSIONS: Our PRC seems to be a valid tool to select candidates for PET/CT imaging in this setting. PET/CT detected malignancy in a significant proportion of patients with invasive cancer.