68Ga-PSMA expression changes on PET/CT for response assessment during taxane-based chemotherapy in metastatic prostate cancer patients.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 35-35
Author(s):  
Qaid Shagera ◽  
Carlos Artigas ◽  
Patrick Flamen
Keyword(s):  
Prostate Cancer ◽  
Metastatic Prostate Cancer ◽  
Response Assessment ◽  
Biological Data ◽  
Psma Pet ◽  
Pet Ct ◽  
Psa Response ◽  
The Mean ◽  
Mean Time ◽  
Psma Expression

35 Background: Imaging-based response to systemic therapies in metastatic prostate cancer is still challenging. The aim of this study was to retrospectively investigate the association between Prostate-Specific Membrane Antigen (PSMA) expression changes on 68Ga PSMA PET/CT and the response to treatment following the start of taxane-based chemotherapies (docetaxel or cabazitaxel) in both metastatic hormonosensitive (mHSPC) and castration-resistant prostate cancer (mCRPC) patients. Methods: We retrospectively reviewed all 68Ga-PSMA-11 PET/CT scans performed at our institution from November 2014 to June 2020. We included mHSPC and mCRPC patients with a baseline 68Ga-PSMA PET/CT performed < 2 months before, and a second 68Ga-PSMA PET/CT performed < 3 months after docetaxel or cabazitaxel (with no modification in therapy between scans). The biological data was used to distinguish PSA-non-responders (increasing PSA or decreasing PSA by < 50% from pretherapy level) and PSA-responders (decreasing PSA > 50% following the start of therapy or the peak thereafter). The PSMA PET/CT response was assessed visually by two independent nuclear medicine physicians blinded to clinical data and patient outcomes. Patients were classified as PSMA-non-responders (≥1 new PSMA-expressing metastases, majority of PSMA-expressing metastases increasing in intensity, or stable PSMA-expression of the disease) or PSMA-responders (complete disappearance of pathologic PSMA uptake, or majority of PSMA-expressing metastases decreasing in intensity). Majority of lesions was defined as > 50% of registered lesions. Descriptive statistics and measures of associations (two-sided Fisher’s exact test and Phi coefficient) were calculated. Results: A total of 37 patients were included (8 mHSPC and 29 mCRPC), 21 patients under docetaxel and 16 cabazitaxel. All patients received at least 3 cycles [median 6 (range 3-10)]. The mean time (±standard deviation) between the first 68Ga-PSMA PET/CT and the start of therapy was 22±16 days. The mean time between the the last cycleand the second 68Ga-PSMA PET/CT was 36±27 days. PSA-response and PSMA-response were concordant in 95% of cases with 18 patients PSA/PSMA-non-responders and 17 PSA/PSMA-responders (Phi = 0.90, p = 0.0001). Two discordant patients presented with PSMA-response but PSA-non-response. No isolated PSMA flare was observed, as PSA-response was always associated with a decrease in PSMA-expression on the second PET/CT. Conclusions: This retrospective study suggests PSMA expression changes on PET/CT at least after 3 cycles of chemotherapy (docetaxel or cabazitaxel) are strongly associated with PSA response. No flare phenomenon was found at this evaluation. Prospective studies are needed to better define the potential role of PSMA-PET/CT in response assessment.

68Ga-PSMA PET/CT for response assessment and outcome prediction in metastatic prostate cancer patients treated with taxane-based chemotherapy

2021 ◽  
pp. jnumed.121.263006
Author(s):  
Qaid Ahmed Shagera ◽  
Carlos Artigas ◽  
Ioannis Karfis ◽  
Gabriela Critchi ◽  
Nieves Martinez Chanza ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Patients ◽  
Metastatic Prostate Cancer ◽  
Outcome Prediction ◽  
Response Assessment ◽  
Psma Pet ◽  
Pet Ct

Local ablative radiotherapy: A means to revert low volume castration-resistant prostate cancer into a hormone-sensitive status?

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 188-188
Author(s):  
Tobias Hölscher ◽  
Fabian Lohaus ◽  
Klaus Zoephel ◽  
Manfred Wirth ◽  
Michael Baumann ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Stereotactic Ablative Radiotherapy ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Psma Pet ◽  
Psa Response ◽  
Psa Nadir ◽  
The Mean ◽  
Low Volume ◽  
Mean Time

188 Background: (Stereotactic) Ablative radiotherapy (aRT) in patients with oligometastatic prostate cancer is safe, achieves high local control rates and its clinical benefit is currently being addressed in clinical trials. However, the selection of patients benefitting most from aRT remains unclear. Moreover, the highly specific and sensitive multimodality functional imaging modality, 68Ga-PSMA-PET-CT/-MR, is widely available. Therefore, we retrospectively evaluated the efficacy of PSMA-PET guided local aRT in low volume oligometastatic castration resistant prostate cancer (CRPC) patients. Methods: Fifteen patients with metachronous oligometastatic CRPC as diagnosed on PSMA-PET were treated with local aRT. Nine patients were treated with a conventionally fractionated regime (25 x 2 Gy) and six with stereotactic hypofractionated RT (3 x 10 Gy), while in all androgen deprivation was continued. The time to PSA-progression, i.e. PSA-nadir + 2 ng/ml (PSA+2) was estimated with the Kaplan-Meier method and compared to an individually estimated time to PSA+2 according to the individually calculated pre-RT PSA doubling time (PSA-DT). Results: At staging PSMA-PET, the median PSA was 3.4 ng/ml (range 1.3 -14.5) and the median PSA-DT was 3.2 months (range 0.6 - 15.3). In four patients no PSA-response after aRT was observed. The responding eleven patients (73%) had a mean decrease in PSA-level of 80% from baseline. The mean time to PSA-nadir was 10.7 months (range 4.5 - 11.5). The mean time to PSA+2 or last follow-up was 15.6 months [95%CI: 9.7 - 21.4] compared to 3.3 months [95%CI: 1.5 - 5.1] estimated PSA-DT without local aRT (p < 0.001). Conclusions: A relevant subset of patients with 68Ga PSMA-PET-detected oligometastatic low volume CRPC had a meaningful PSA-response with aRT. They were reverted into an earlier stage of their disease again. A prospective clinical trial on this clinically highly relevant question is being prepared.

18: PSMA-PET-Based Response Assessment of Metastatic Prostate Cancer Response to Radiotherapy: A Case Series

2021 ◽  
Vol 163 ◽  
pp. S11
Author(s):  
Aruz Mesci ◽  
Mohammad Gouran-Savadkoohi ◽  
Jeffrey Greenspoon ◽  
Anil Kapoor ◽  
Himanshu Lukka ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Metastatic Prostate Cancer ◽  
Case Series ◽  
Response Assessment ◽  
Psma Pet

Characterization of PSMA and 18F-fluciclovine transporter gene expression in localized prostate cancer.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 295-295
Author(s):  
Carissa Chu ◽  
Mohammed Alshalalfa ◽  
Martin Sjöström ◽  
Shuang Zhao ◽  
Annika Herlemann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Clinical Outcomes ◽  
Molecular Subtypes ◽  
Localized Prostate Cancer ◽  
Transporter Gene ◽  
Psma Pet ◽  
Pet Ct ◽  
Genomic Risk ◽  
Psma Expression

295 Background: While 18F-fluciclovine PET/CT is approved in the US and recommended by the NCCN, prostate-specific membrane antigen (PSMA) PET/CT is more common in Europe/Australia and recommended by the EAU. Less is known about the biology of lesions detected by either modality. 18F-fluciclovine PET relies on radiotracer uptake by amino acid transporters LAT1-4 and ASCT1-2. PSMA PET is dependent on surface expression of PSMA. We compared relative expression of PSMA and fluciclovine transporter genes in radical prostatectomy (RP) samples to determine their distribution across subtypes and correlation with outcomes. Methods: Gene expression data of 19,102 RP samples were analyzed using the Affymetrix Human Exon 1.0 ST microarray. 1,135 patients had long term follow up. Associations between expression of PSMA and fluciclovine transporter genes (LAT1-4 and ASCT1-2) and pathologic variables, molecular subtypes, and clinical outcomes were conducted. Results: All fluciclovine transporter genes (LAT 1-4, ASCT1-2) were expressed at lower levels than PSMA (p <0.0001). PSMA expression was positively correlated with genomic risk score and pathologic Gleason score (p<0.0001), but LAT2-3 and ASCT2 were inversely correlated with genomic risk in primary tumors (p<0.0001) and less expressed in GS 9-10 tumors (p<0.0001). PSMA expression was associated with worse metastasis-free survival (MFS) (HR 1.45, p=0.001) and lymph node involvement (HR 2.14, p<0.0001). Expression of LAT2, LAT3, ASCT2 expression was associated with better MFS (HR 0.85, 0.63, 0.74, p<0.0001-0.04). After multivariable adjustment, PSMA expression remained independently prognostic of poorer MFS (HR 1.3, p=0.028). Luminal B subtype was notable for PSMA overexpression; Luminal A was enriched in ASCT2 and LAT2 (p<0.0001). PSMA expression did not correlate with ERG fusion prostate cancers, but LAT2, ASCT1, and ASCT2 were overexpressed in ERG fusion negative tumors (p<0.0001). Conclusions: PSMA expression is associated with more aggressive disease and poorer clinical outcomes than fluciclovine transporter genes in localized prostate cancer. Molecular subtypes of prostate cancer vary in PSMA and fluciclovine transporter gene expression.

scholarly journals Immunohistochemical Validation of PSMA Expression Measured by 68Ga-PSMA PET/CT in Primary Prostate Cancer

2017 ◽  
Vol 59 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Nadine Woythal ◽  
Ruza Arsenic ◽  
Carsten Kempkensteffen ◽  
Kurt Miller ◽  
Jan-Carlo Janssen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Primary Prostate Cancer ◽  
Psma Pet ◽  
Pet Ct ◽  
Psma Expression

scholarly journals Prior PSMA PET-CT Imaging and Hounsfield Unit Impact on Tumor Yield and Success of Molecular Analyses from Bone Biopsies in Metastatic Prostate Cancer

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3756
Author(s):  
Minke Smits ◽  
Kamer Ekici ◽  
Samhita Pamidimarri Naga ◽  
Inge M. van Oort ◽  
Michiel J. P. Sedelaar ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Molecular Characterization ◽  
Metastatic Prostate Cancer ◽  
Ct Imaging ◽  
Ct Guidance ◽  
Prediction Tool ◽  
Psma Pet ◽  
Pet Ct ◽  
Bone Biopsies ◽  
Tumor Yield

Developing and optimizing targeted therapies in metastatic castration-resistant prostate cancer (mCRPC) necessitates molecular characterization. Obtaining sufficient tumor material for molecular characterization has been challenging. We aimed to identify clinical and imaging variables of imaging-guided bone biopsies in metastatic prostate cancer patients that associate with tumor yield and success in obtaining molecular results, and to design a predictive model: Clinical and imaging data were collected retrospectively from patients with prostate cancer who underwent a bone biopsy for histological and molecular characterization. Clinical characteristics, imaging modalities and imaging variables, were associated with successful biopsy results. In our study, we included a total of 110 bone biopsies. Histological conformation was possible in 84 of all biopsies, of which, in 73 of the 84, successful molecular characterization was performed. Prior use of PSMA PET-CT resulted in higher success rates in histological and molecular successful biopsies compared to CT or MRI. Evaluation of spine biopsies showed more often successful results compared to other locations for both histological and molecular biopsies (p = 0.027 and p = 0.012, respectively). Low Hounsfield units (HUs) and deviation (Dev), taken at CT-guidance, were associated with histological successful biopsies (p = 0.025 and p = 0.023, respectively) and with molecular successful biopsies (p = 0.010 and p = 0.006, respectively). A prediction tool combining low HUs and low Dev resulted in significantly more successful biopsies, histological and molecular (p = 0.023 and p = 0.007, respectively). Based on these results, we concluded that site selection for metastatic tissue biopsies with prior PSMA PET-CT imaging improves the chance of a successful biopsy. Further optimization can be achieved at CT-guidance, by selection of low HU and low Dev lesions. A prediction tool is provided to increase the success rate of bone biopsies in mCRPC patients, which can easily be implemented in daily practice.

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