¹⁸F-PSMA1007 PET/CT in the context of biochemical recurrence of prostate cancer: An economical experience from a Latin American reference center.

47 Background: 25-30% of patients present with biochemical recurrence of prostatic adenocarcinoma (PCa) after primary tumor treatment. One of the options indicated for the study of recurrence is PET/CT PSMA. In our center we use the 18F-PSMA1007, which has a cost of approximately $1,342, while the alternative cost (68Ga-PSMA-11) is $2,422. The aim of this study is to evaluate the performance of 18F-PSMA-1007 PET/CT in patients with biochemical recurrence after definitive therapy. Methods: A cross-sectional study that included patients with a biochemical recurrence and who underwent 18F-PSMA1007 PET/CT in our center of reference between 2020-2022. Biochemical recurrence was defined as a PSA >0.1 ng/dL in prostatectomy and a value of nadir PSA + 2ng/ml in radiotherapy. Descriptive analysis was performed with frequencies for discrete variables, and central tendency and dispersion measures for continuous variables. Detection rates were evaluated according to primary tumor treatment and PSA values. To compare categorical variables, we use Chi-square and t-Test for continuous variables. This analysis was performed using SPSS statistical software. Results: A total of 154 patients were included, 84% (n=129) with radical prostatectomy and 16% (n=25) received management with radiotherapy. Of the first group, 75.2% had evidence of recurrence on 18F-PSMA-1007 PET/CT, while of the second group, 92% had evidence. The descriptive analysis is shown. A statistically significant difference was found in local recurrence and bone metastasis. In terms of metastases, 26,3% of post-surgical patients had bone metastasis and a higher percentage (52%) of those who underwent radiotherapy, with concomitant involvement of both the axial and appendicular skeleton in both groups. In the prostatectomy group, the detection rates for PSA levels <0.25, 0.25 - <0.5, 0.5-< 1, 1-2, 2 - < 5, 5 - <10, ≥10 were 12.5%, 48.3%, 79.2%, 84.2%, 96%,90% and 100% respectively. In the radiotherapy group, the detection rates for PSA levels 2 - <5, 5<10, ≥10 were 87,5%, 100% and 100%, respectively. Conclusions: 18F-PSMA-1007 PET/CT is an alternative option that offers similar detection ranges and is more economical than 68Ga-PSMA-11 in our population, allowing effective detection of biochemical PCa recurrence in central and remote locations, where fluorine is not consistently available. [Table: see text]