Preliminary results on response assessment using 68Ga-HBED-CC-PSMA PET/CT in patients with metastatic prostate cancer undergoing docetaxel chemotherapy

Abstract

Our preliminary results suggest that Ga-PSMA PET might be a promising method for treatment response assessment in mCSPC and mCRPC. The data indicate that for different metastatic sites, the performance ofGa-PSMA PET in response assessment might be superior to that of the conventional CT approach and could help differentiate between progressive disease and treatment response. Because of the limited number of patients, the differences revealed in our study were not statistically significant. Thus larger and prospective studies are clearly needed and warranted to confirm the value of Ga-PSMA PET as an imaging biomarker for response assessment.

Response assessment using [68Ga]Ga‐PSMA ligand PET in patients undergoing systemic therapy for metastatic castration‐resistant prostate cancer

“…3,4 In this regard, PSMA 11-PET/CT (MRI), which combines morphological with functional imaging, has shown promising results concerning response assessment in two recently published studies. 12,13 This is in agreement with preclinical studies, which have demonstrated that PSMA uptake in the tumor reliably reflects the number of living tumor cells. 16 Another study evaluating the role of PSMA dynamics in men undergoing treatment for advanced PC showed that the PSMA expression in circulating tumor cells shows promising results as a dynamic marker for therapy response.…”

“…The PET parameters SUVmean and PSMA TTV have been used and investigated for response assessment in this setting in studies before. 12,13 To the best of our knowledge, this is the first study additionally providing response data for the PET parameters SUVmax, SUVpeak, and TTV in a cohort treated with systemic therapies other than radioligand therapy. Within our whole cohort of 67 systemic therapies for mCRPC patients, we could show that all the observed PSMA 11-PET parameter, as well as RECIST criteria, showed significant associations with BR (dTTV P = .003, dSUVmean P = .003, dSUVmax P = .011, dSUVpeak P < 0,001, which is another argument for using hybrid imaging techniques combining morphological and functional imaging information.…”

“…Changes in PSA levels served as a measure of biochemical response (BR). 12,13 Biochemical complete response (CR) was defined as a PSA level of 0 ng/mL after systemic therapy, partial response (PR) as a decrease of serum PSA ≥50% from the baseline level and progressive disease (PD) as an increase of serum PSA by ≥25%. A change in PSA after therapy between −49% and +24% was defined as stable disease (SD).…”

Early Experience of Rechallenge 177Lu-PSMA Radioligand Therapy After an Initial Good Response in Patients with Advanced Prostate Cancer

“…However, 177 Lu-PSMA RLT has been introduced only recently and the number of patients with an excellent response is limited. Second, because of the lack of an established system to evaluate response on PSMA PET, we adopted PERCIST 1.0, as previously described (8). The validation of PERCIST for non-18 F-FDG application is still under discussion.…”

“…Biochemical response was defined as a PSA decline of at least 30%, 50%, and 90% during initial and rechallenge treatment. For radiographic response, 68 Ga-PSMA-11 PET/CT findings were assessed as described recently (8). Clinical response was assessed by Eastern Cooperative Oncology Group performance status and changes in bone pain from the Brief Pain Inventory.…”