The maximum standardized uptake value in patients with recurrent or persistent prostate cancer after radical prostatectomy and PSMA-PET-guided salvage radiotherapy—a multicenter retrospective analysis

Abstract

Purpose This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET) prior to salvage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort. Methods Patients who underwent 68 Ga-PSMA11-PET prior to sRT were enrolled in four high-volume centers in this retrospective multicenter study. Only patients with PET-positive local recurrence (LR) and/or nodal recurrence (NR) within the pelvis were included. Patients were treated with intensity-modulated-sRT to the prostatic fossa and elective lymphatics in case of nodal disease. Dose escalation was delivered to PET-positive LR and NR. Androgen deprivation therapy was administered at the discretion of the treating physician. LR and NR were manually delineated and SUVmax was extracted for LR and NR. Cox-regression was performed to analyze the impact of clinical parameters and the SUVmax-derived values on BRFS. Results Two hundred thirty-five patients with a median follow-up (FU) of 24 months were included in the final cohort. Two-year and 4-year BRFS for all patients were 68% and 56%. The presence of LR was associated with favorable BRFS (p = 0.016). Presence of NR was associated with unfavorable BRFS (p = 0.007). While there was a trend for SUVmax values ≥ median (p = 0.071), SUVmax values ≥ 75% quartile in LR were significantly associated with unfavorable BRFS (p = 0.022, HR: 2.1, 95%CI 1.1–4.6). SUVmax value in NR was not significantly associated with BRFS. SUVmax in LR stayed significant in multivariate analysis (p = 0.030). Sensitivity analysis with patients for who had a FU of > 12 months (n = 197) confirmed these results. Conclusion The non-invasive biomarker SUVmax can prognosticate outcome in patients undergoing sRT and recurrence confined to the prostatic fossa in PSMA-PET. Its addition might contribute to improve risk stratification of patients with recurrent PCa and to guide personalized treatment decisions in terms of treatment intensification or de-intensification. This article is part of the Topical Collection on Oncology—Genitourinary.

Gene’s expression underpinning the divergent predictive value of [18F]F-fluorodeoxyglucose and prostate-specific membrane antigen positron emission tomography in primary prostate cancer: a bioinformatic and experimental study

“…This concept is corroborated by the specificity of the radioactive signal documented by the strict adherence of tracer uptake kinetics with the ligand-receptor model. Thus, in clinical studies assessing the prognostic value of PSMA PET imaging in early-stage PCa [ 10 – 13 , 15 , 47 ], the most common metrics adopted to quantify the PSMA-targeting tracer accumulation at PET imaging (i.e., SUV) may be influenced by several variables beyond FOLH1 expression, including PSMA-expressing cellular density or tumour burden. Based on our results, it can be hypothesized that the prognostic power of PSMA PET in this clinical setting might predominantly reflect these tumour characteristics rather than identifying a specific feature of PCa biological aggressiveness.…”

“…Several studies have already reported a direct correlation between the degree of PSMA tracer uptake and histopathological features of disease severity, including the Gleason Score [ 9 – 12 ]. Coherently, the higher the PSMA tracer uptake by the primary tumour, the lower the long-term clinical outcome [ 13 ]. However, the PSMA PET prognostic penetrance is challenged by the acknowledged limitation of PET imaging that underestimates tracer concentration in small tumours and by the notion that 5–10% of clinically relevant PCa do not express this protein [ 14 , 15 ].…”

PSMA-PET/CT-guided salvage radiotherapy in recurrent or persistent prostate cancer and PSA < 0.2 ng/ml

“…Future studies with more patients and longer followup should assess this question. In addition, a study by Spohn et al proposed that the SUVmax value with the local recurrent disease on PSMA-PET/CT images might be a predictive factor for BRFS after sRT [15].…”

Combined forced diuresis and late acquisition on [68Ga]Ga-PSMA-11 PET/CT for biochemical recurrent prostate cancer: a clinical practice-oriented study

“…These cutoffs were not externally validated, and it is generally challenging to translate SUV-derived cutoffs in the clinical setting [ 39 ]. Nevertheless, former studies tentatively explored the discriminative potential of SUV-derived cutoffs in [ 68 Ga]Ga-PSMA-11 PET/CT, even in multicentric settings [ 40 ]. Moreover, ΔSUVmax minimizes the effects of many confounding factors representing the difference between late- and early-phase imaging in the same patient.…”