Impact of 68Ga-PSMA PET/CT in the treatment of prostate cancer: Initial experience in Spain.

AIM: To evaluate whether positron-emission tomography/computed tomography with 68Ga-PSMA (68Ga-PSMA PET/CT) influences the therapeutic management of patients with primary or recurrent prostate cancer (PCa). BACKGROUND: Although 68Ga-PSMA PET/CT is one of the best options for staging or restaging patients with PCa, its availability is still very limited in Spain. The present study reports the results of the first group of patients in Spain who underwent 68Ga-PSMA PET/CT imaging. MATERIALS AND METHODS: All patients (n = 27) with a histological diagnosis of PCa who underwent 68Ga-PSMA PET/CT prior to the definitive treatment decision at the only centre with this technology in Spain during 2017-2018 were included. Two nuclear medicine physicians and a radiologist reviewed the imaging studies. The clinical impact was assessed from a theoretical perspective, based on the treatment that would have been applied if no data from the 68Ga-PSMA PET/CT were available. RESULTS: Most patients (n = 26; 96%) had persistent disease or biochemical recurrence after radical prostatectomy, radiotherapy, or combined treatment. One patient underwent 68Ga-PSMA PET/CT imaging to stage high-risk PCa. Overall, 68Ga-PSMA PET/CT was positive in 19 patients (70.4%). In 68.75% of these patients, none of the other imaging tests-MRI, CT, or bone scans-performed prior to the 68Ga-PSMA PET/CT were able to detect the presence of cancerous lesions. Overall, the findings of the 68Ga-PSMA PET/CT led to a modification of the therapeutic approach in 62.96% of the patients in the study. CONCLUSIONS: 68Ga-PSMA PET/CT alters the therapeutic approach in a substantial proportion of patients with PCa.

Ability of final PET/CT to predict response to first-line treatment in real patients with classical Hodgkin lymphoma.

Up to 25% of patients with classical Hodgkin lymphoma (cHL) and a negative interim PET/CT will progress. Unfortunately, there are few published studies on the predictive value of PET/CT performed after finishing treatment. The objective of our study was to assess the role of the final PET/CT (fPET/CT) in predicting progression in a retrospective series of patients treated in the last 10 years with a homogeneous protocol (ABVD + / - radiotherapy). We reviewed a cohort of 227 patients with newly diagnosed cHL. fPET/CT was performed on 212 patients (93%). In patients with a positive fPET, progression-free survival at 60 months was 17% (94% if fPET was negative, p = 0.000). The positive and negative predictive values for the fPET were 76% and 94%, respectively (Fisher's exact test, p = 0.000). In the subgroup of patients with advanced-stage cHL, progression-free survival at 60 months was 91% with negative fPET and 0% with positive fPET (p = 0.000). However, fPET was negative in 19 of the 29 patients with a positive interim PET/CT (only 2 showed progression). In conclusion, fPET is a useful tool to predict treatment failure in patients with newly diagnosed cHL, especially advanced-stage disease.