Effects of continuous androgen deprivation therapy on tracer uptake in primary prostate cancer in PSMA PET/CT

SummaryAim: To assess whether clinical prostate cancer (PCA) related factors and therapy status can predict the degree of tracer uptake on [68Ga]PSMA-HBED-CC PET/CT.Materials & methods: We retrospectively studied 124 patients with recurrent an/or metastatic PCA who underwent [68Ga]PSMAHBED-CC PET/CT. The maximum standardized uptake value (SUVmax) was determined in the prostate bed as well as in three size categories (≤ 5 mm, > 5–15 mm, > 15 mm) in pelvic lymph node, extrapelvic lymph node, bone and visceral metastases.Results: Significant positive correlations between lesion size and SUVmax were found in pelvic lymph node metastases > 5 -≤15 mm (Spearmans rho = 0.502, p = 0.002) as well as in extrapelvic lymph node metastases5 mm (rho = 0.314, p = 0.033) and > 5 ≤-15 mm (rho = 0.614, p < 0.001). SUVmax tended to be higher in the largest diameter category in each anatomic station than in the middle and lower categories. We were unable to find evidence for a relationship between SUVmax and PSA, PSAdt, Gleason score, androgen deprivation therapy, radiation therapy or chemotherapy status.Conclusion: Measured tracer uptake in [68Ga]PSMA-HBED-CC PET/CT in patients with recurrent/metastasized prostate cancer is significantly influenced by lesion size as a result of partial volume effects in the very small lesions. Clinical indicators of aggressive prostate cancer behaviour such as PSA levels, PSA doubling time or the Gleason score of the primary tumour, as well as the androgen deprivation therapy, radiation therapy or chemotherapy status are not related to measured tracer uptake.

Download Full-text

The effect of androgen deprivation therapy on 68GA-PSMA-tracer uptake in nonmetastatic prostate cancer patients.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.6_suppl.22 ◽

2020 ◽

Vol 38 (6_suppl) ◽

pp. 22-22

Author(s):

Onal Cem ◽

Ozan Cem Guler ◽

Nese Torun ◽

Mehmet Reyhan ◽

Ali Fuat Yapar

Keyword(s):

Prostate Cancer ◽

Cancer Patients ◽

Tracer Uptake ◽

Androgen Deprivation ◽

Post Treatment ◽

Ct Scans ◽

Baseline Serum ◽

Psma Pet ◽

Pet Ct ◽

Psa Response

22 Background: To evaluate the effect of neoadjuvant androgen deprivation treatment (ADT) on prostate specific membrane antigen (PSMA) tracer uptake demonstrated in 68Ga-PSMA-positron emission tomography (PET/CT) in non-metastatic hormone-naïve prostate cancer patients. Methods: The clinical data of 108 prostate cancer patients who received neoadjuvant ADT were retrospectively analyzed. All patients had a baseline 68Ga-PSMA-PET/CT scan and a second scan was delivered median of 2.9 months after initiation of ADT. Patients with clinical and radiological evidence of distant metastasis were excluded from the study. The maximum standardized uptake value (SUVmax) of primary tumor (SUVp) and metastatic lymph nodes (SUVln) as well as PSA response were assessed between pre- and post-ADT 68Ga-PSMA-PET/CT scans. Results: The median SUVp and SUVln were 14.0 (range, 4.9 – 78.4) and 13.2 (range, 3.6 – 64.5), respectively. There was a significant moderate correlation between baseline serum PSA and SUVp (Spearman = 0.513, p<0.001). There were significant decreases in post-treatment serum PSA, SUVp, and SUVp. A decrease in SUVp was seen in 91 patients (84%) with a median value of 66% (range, 5% – 100%), while 17 patients (16%) had no change in or an increase in PSMA tracer uptake with a median value of 24% (range, 0% – 198%). Patients with Gleason score (GS) of 7 had significantly higher metabolic response rates compared to other patients. The disease progression was significantly higher only in patients with GS > 7 disease compared to GS 7 disease. The PSA response to ADT was lowest in patients with ISUP high-grade tumors. A total of 16 patients (15%) had progressive disease, and in 9 patients (8%), radiotherapy decisions were modified according to post-treatment 68Ga-PSMA-PET/CT scans. Conclusions: The current study includes the largest number of patients analyzed to date and demonstrates that ADT causes a significant decrease in serum PSA values and SUVp and SUVln. The authors demonstrate that 68Ga-PSMA-PET/CT may be used as a quantitative imaging modality after neoadjuvant ADT in hormone-naïve non-metastatic PC patients.

Download Full-text

Can 68 Ga-PSMA-11 PET/CT Predict Pathologic Response of Primary Prostate Cancer to Neoadjuvant Androgen Deprivation Therapy: A Pilot Study

The Journal of Urology ◽

10.1097/ju.0000000000001481 ◽

2020 ◽

Author(s):

Mengxia Chen ◽

Junlong Zhuang ◽

Yao Fu ◽

Suhan Guo ◽

Shiming Zang ◽

...

Keyword(s):

Prostate Cancer ◽

Pilot Study ◽

Androgen Deprivation Therapy ◽

Pathologic Response ◽

Androgen Deprivation ◽

Primary Prostate Cancer ◽

Pet Ct

Download Full-text

OC-0208: Comparison between 68Ga-PSMA-PET/CT and mpMRI for radiotherapy planning in primary prostate cancer

Radiotherapy and Oncology ◽

10.1016/s0167-8140(21)00232-2 ◽

2020 ◽

Vol 152 ◽

pp. S104

Author(s):

S. Spohn ◽

C. Jaegle ◽

A.S. Bettermann ◽

S. Kiefer ◽

C.A. Jilg ◽

...

Keyword(s):

Prostate Cancer ◽

Radiotherapy Planning ◽

Primary Prostate Cancer ◽

Psma Pet ◽

Pet Ct

Download Full-text

Prospective study on the effect of short-term androgen deprivation therapy on PSMA uptake evaluated with 68Ga-PSMA-11 PET/MRI in men with treatment-naïve prostate cancer

European Journal of Nuclear Medicine and Molecular Imaging ◽

10.1007/s00259-019-04635-7 ◽

2019 ◽

Vol 47 (3) ◽

pp. 665-673 ◽

Cited By ~ 5

Author(s):

Otto Ettala ◽

Simona Malaspina ◽

Terhi Tuokkola ◽

Pauliina Luoto ◽

Eliisa Löyttyniemi ◽

...

Keyword(s):

Prostate Cancer ◽

Bone Metastases ◽

Androgen Deprivation Therapy ◽

Time Course ◽

Specific Antigen ◽

Androgen Deprivation ◽

Short Term ◽

Psma Pet ◽

Treatment Naïve

Abstract Purpose Based on in vitro studies, it is known that androgen deprivation therapy (ADT) increases prostate-specific membrane antigen (PSMA) expression. Therefore, we hypothesised that ADT improves the performance of PSMA-PET imaging in primary staging of prostate cancer. The purpose of the study was to demonstrate the time course effect of ADT on PSMA uptake in different types of metastatic lesions evaluated with 68Ga-PSMA-11 PET/MRI. Methods Nine men with treatment-naïve prostate cancer were enrolled to a prospective, registered (NCT03313726) clinical trial. A 68Ga-PSMA-11 PET/MRI was performed once before and 3 times post-ADT (degarelix, Firmagon). Change of maximum standardised uptake values (SUVmax) in prostate, lymph nodes, bone metastases, and physiologically PSMA-avid organs were evaluated in a time frame of 1–8 weeks. Results All patients reached castration levels within 10 days, and 50% decrease in prostate-specific antigen (PSA) concentration was observed 14 days post-ADT. A heterogeneous increase in PSMA uptake was observed 3 to 4 weeks post-ADT. This phenomenon was definitively more evident in bone metastases: 13 (57%) of the metastasis, with a mean (range) SUVmax increase of 77% (8–238%). In one patient, already having bone metastases at baseline, three new bone metastases were observed post-ADT. Of lesions with reduced SUVmax, none disappeared. Conclusions Both in patient and region level, increase in PSMA uptake post-ADT is heterogenous and is seen most evidently in bone metastases. Preliminary results on a small cohort of patients suggest the clinical impact of ADT on improving the performance of 68Ga-PSMA PET in staging seems to be minor. However, the optimal imaging time point might be 3 to 4 weeks post-ADT. Since none of the metastases with decreasing SUVmax disappeared, it seems that short-term usage of ADT does not interfere with the interpretation of 68Ga-PSMA PET. Trial registration NCT03313726, registered 18 October 2017; EUDRA-CT, 2017-002345-29.

Download Full-text