Interim PSMA PET/CT for response evaluation during LuPSMA treatment in mCRPC (INTERIM PET): An explorative, multicenter study.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5066-5066
Author(s):  
Andrei Gafita ◽  
Isabel Rauscher ◽  
Manuel Weber ◽  
Boris A. Hadaschik ◽  
Hui Wang ◽  
...  

5066 Background: The aim of this analysis was to evaluate the prognostic value of interim PSMA PET/CT in men with metastatic castration-resistant prostate cancer (mCRPC) treated with 177Lu-PSMA and to develop a novel framework for Response Evaluation Criteria In PSMA-imaging (RECIP). Methods: This was an explorative, multicenter, retrospective study; 124 men with mCRPC who underwent 177Lu-PSMA treatment and received PSMA-PET/CT at baseline (bPET) and at interim after two cycles of treatment (iPET) met the eligibility criteria and were included in this analysis. The primary endpoint was overall survival (OS). Pairs of bPET and iPET were interpreted by three independent readers for appearance of new lesions. Whole-body tumor lesions were segmented using qPSMA software and total PSMA-positive tumor volume (PSMA-VOL) was obtained. Changes in PSMA-VOL on iPET relative to bPET were calculated. After being tested separately for associations with OS, appearance of new lesions and changes in PSMA-VOL were combined to develop RECIP. Results: The median OS was 13.5 months (95%CI, 11.6-15.4). Appearance of at least one new lesion on iPET was observed in 73 (59%) patients and was associated with poor OS (hazard ratio [HR] 2.23; 95%CI, 1.51-3.28; P <.001). Based on the current data, RECIP were defined as: partial response (PSMA-PR) as a decline ≥20% in PSMA-VOL and no appearance of new lesions; progressive disease (PSMA-PD) as an increase ≥20% in PSMA-VOL and appearance of new lesions; stable disease (PSMA-SD) was defined as any condition but not PSMA-PR or PSMA-PD. The OS of men with PSMA-PD (n = 41) was significantly worse compared to men with PSMA-SD (n = 47; HR 2.52; 95%CI, 1.61–3.93; P <.001) and PSMA-PR (n = 36; HR 4.16; 95%CI, 2.54–6.78; P <.001). PSMA-SD was associated with significantly worse OS compared to PSMA-PR (HR 1.65; 95%CI, 1.02–2.65; P =.039). The time dependent C-index of associations with OS for response according to RECIP was 0.68 (95%CI, 0.63-0.72). Conclusions: Interim staging using PSMA-PET/CT and response classification by RECIP is prognostic for survival of men with mCRPC treated with 177Lu-PSMA. Validation of these findings in clinical trials is warranted.

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. TPS332-TPS332 ◽  
Author(s):  
Michael Hofman ◽  
Louise Emmett ◽  
John A Violet ◽  
Nicola Jane Lawrence ◽  
Scott Williams ◽  
...  

TPS332 Background: Lutetium-177 [177Lu]-PSMA-617 is a novel radiolabelled small molecule that binds with high affinity to prostate-specific membrane antigen (PSMA), which is commonly overexpressed in prostate cancer. This treatment has demonstrated promising activity and tolerability in men progressing after multiple lines of chemotherapy and endocrine therapy. This trial will determine the activity and safety of 177Lu-PSMA-617 compared to cabazitaxel chemotherapy in men with progressive metastatic castrate resistant prostate cancer. Methods: TheraP is an open-label, randomised, two-arm, multi-centre, phase 2 trial comparing the activity and safety of experimental treatment with [177Lu]-PSMA-617 versus standard 2nd line chemotherapy with cabazitaxel. Key eligibility criteria include prior chemotherapy with docetaxel; rising serum PSA; sufficient PSMA avidity according to central reviewed of imaging with PSMA PET/CT and FDG PET/CT; no discordance between FDG PET and PSMA PET. The trial will include 200 participants randomised in a 1:1 ratio to either [177Lu]-PSMA-617 intravenously every 6 weeks, 8.5 GBq for cycle 1, decreasing by 0.5 GBq with each subsequent cycle, up to maximum 6 cycles (experimental group); or, chemotherapy with cabazitaxel (20 mg/m2) intravenously every 3 weeks, for 10 cycles (standard group). In the event of an exceptional response to [177Lu]-PSMA-617, according to centrally-reviewed, post-therapy SPECT imaging, treatment is suspended but can recommence subsequently on progression. The primary endpoint is a 50% or greater reduction from baseline in serum PSA. Secondary endpoints include overall survival, progression-free survival (PFS), PSA-PFS, pain-PFS, radiographic-PFS, health-related quality of life, pain response, and adverse events. The outcomes of patients excluded because of discordant disease on FDG PET and PSMA PET will be reported as a tertiary objective. The study has accrued 79 of 200 planned participants from 29 January 2018 to 23 October 2018. Clinical trial information: NCT03392428.


2021 ◽  
Vol 60 (06) ◽  
pp. 417-424
Author(s):  
Lara Franziska Stolzenbach ◽  
Florian Löcherbach ◽  
Tobias Maurer ◽  
Christoph Berliner ◽  
Katharina Wargenau ◽  
...  

Abstract Aim Few small-scaled studies performed systematic analysis of the benefits of extending prostate specific membrane antigen positron-emission tomography/ computed tomography (68Ga-PSMA I&T PET/CT) to the lower extremities in prostate cancer (PCa) patients. We hypothesized that 68Ga-PSMA I&T PET/CT positive lesions are rare in lower extremities of prostate cancer (PCa) patients, the clinical implication is negligible and may therefore be omitted. Methods We retrospectively analyzed 1,068 PCa patients who received 68Ga-PSMA I&T PET/CT in a single institution (2016–2018). Of those, 285 (26.7%) were newly diagnosed, 529 (49.5%) had biochemical recurrence (BCR) and 254 (23.8%) were castration-resistant prostate cancer (CRPC) patients. Results Of 1,068 68Ga-PSMA I&T PET/CTs, positive lesions in the lower extremities were identified in 6.9% patients (n=74). Positive lesions in the lower extremities were most common in CRPC patients (19.7%; n=50), followed by newly diagnosed (3.2%; n=9) and BCR (2.8%; n=15) PCa patients. Only 3 patients presented with exclusive lesions in the lower extremities, respectively 0.8% (n=2) in CRPC and 0.4% (n=1) in newly diagnosed PCa. Both CRPC (94.1%, n=47) and BCR (80.0%, n=12) patients with PSMA-positive lesions predominantly received systemic therapy. Conclusion Identification of lower extremities lesions with PSMA PET/CT is uncommon and exclusive lesions are rare. PSMA PET/CT findings of the lower extremities did not change therapy management. Thus, scanning of the lower extremities can be omitted in standard protocols.


2019 ◽  
Vol 58 (06) ◽  
pp. 443-450
Author(s):  
Kerstin Michalski ◽  
Michael Mix ◽  
Philipp T. Meyer ◽  
Juri Ruf

Abstract Aim In patients with metastasized castration-resistant prostate cancer a reliable imaging-based therapy response assessment in addition to PSA kinetics is desirable. Recently, measurements of whole-body tumour burden by [68Ga]PSMA-11 PET/CT have been reported for response assessment in oligometastasic patients. The present study investigated the association of PSMA PET derived parameters and serum PSA level before and after [177Lu]PSMA-617 radioligand therapy (RLT). Methods This retrospective study assessed whole-body PSMA tumour volume (PSMA-TV) in 10 patients with multifocal to diffuse metastases before and after 2 cycles of RLT using volume of interest (VOI) analysis. A standardized uptake value (SUV) threshold-based approach was used to semi-automatically delineate all voxels with a SUV ≥ 2.0 g/ml using the software ROVER® (ABX Radeberg, Germany). Voxels with physiological tracer uptake (e. g. kidneys) were excluded manually. Correlations between PSMA-TV and serum PSA level before and after two cycles of RLT as well as changes thereof (ΔPSMA-TV and ΔPSA, respectively) were calculated. Results Changes of ΔPSMA-TV and ΔPSA were concordant in 7 of 10 patients. Whereas a good correlation was found between PSMA-TV and PSA before RLT (ρ = 0.81, p = 0.0049), this correlation was attenuated after RLT (ρ = 0.64, p = 0.0479). Consequently, no association was found between ΔPSMA-TV and ΔPSA (ρ = 0.39, p = 0.26). Conclusion The attenuation of the correlation of PSA and PSMA-TV after RLT suggests that in patients with advanced disease the comparison of imaging based parameters such as PSMA-TV and PSA level might be useful for an adequate monitoring of treatment response.


2020 ◽  
Vol 13 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Angelo Castello ◽  
Egesta Lopci

Background: Immune checkpoint inhibitors (ICI) have achieved astonishing results and improved overall survival (OS) in several types of malignancies, including advanced melanoma. However, due to a peculiar type of anti-cancer activity provided by these drugs, the response patterns during ICI treatment are completely different from that with “old” chemotherapeutic agents. Objective: To provide an overview of the available literature and potentials of 18F-FDG PET/CT in advanced melanoma during the course of therapy with ICI in the context of treatment response evaluation. Methods: Morphologic criteria, expressed by Response Evaluation Criteria in Solid Tumors (RECIST), immune-related response criteria (irRC), irRECIST, and, more recently, immune-RECIST (iRECIST), along with response criteria based on the metabolic parameters with 18F-Fluorodeoxyglucose (18FFDG), have been explored. Results: To overcome the limits of traditional response criteria, new metabolic response criteria have been introduced on time and are being continuously updated, such as the PET/CT Criteria for the early prediction of Response to Immune checkpoint inhibitor Therapy (PECRIT), the PET Response Evaluation Criteria for Immunotherapy (PERCIMT), and “immunotherapy-modified” PET Response Criteria in Solid Tumors (imPERCIST). The introduction of new PET radiotracers, based on monoclonal antibodies combined with radioactive elements (“immune-PET”), are of great interest. Conclusion: Although the role of 18F-FDG PET/CT in malignant melanoma has been widely validated for detecting distant metastases and recurrences, evidences in course of ICI are still scarce and larger multicenter clinical trials are needed.


Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5564
Author(s):  
Adriana Faiella ◽  
Rosa Sciuto ◽  
Diana Giannarelli ◽  
Marta Bottero ◽  
Alessia Farneti ◽  
...  

Background: We aimed assess the detection rate (DR) of positron emission tomography/computed tomography with two novel tracers in patients referred for salvage radiotherapy (sRT) with a presumed local recurrence at multiparametric magnetic resonance (mpMR) after radical prostatectomy (RP). Methods: The present prospective study was conducted at a single institution between August 2017 and June 2020. Eligibility criteria were undetectable PSA after RP; subsequent biochemical recurrence (two consecutive PSA rises to 0.2 ng/mL or greater); a presumed local failure at mpMR; no distant metastases at 18F-fluorocholine PET/CT (CH/PET); no previous history of androgen deprivation therapy. Patients were offered both 64CuCl2 PET/CT (CU/PET) and 64Cu-PSMA PET/CT (PSMA/PET) before sRT. After image co-registration, PET findings were compared to mpMR ones in terms of DR and independent predictors of DR investigated at logistic regression. Results: A total of 62 patients with 72 nodules at mpMR were accrued. Compared to mpMR (DR = 100%, 95%CI: 94.9–100%), DRs were 47.2% (95%CI: 36.1–58.6%) and 54.4% (95%CI: 42.7–65.7%) for CU/PET and PSMA/PET, respectively (p < 0.001 for both). Both experimental PET/CT performed particularly poorly at PSA levels consistent with early sRT. Conclusions: The two novel radiotracers are inferior to mpMR in restaging the prostatic fossa for sRT planning purposes, particularly in the context of early salvage radiotherapy.


2020 ◽  
Vol 13 (2) ◽  
pp. 94-98 ◽  
Author(s):  
Francesco Bertagna ◽  
Domenico Albano ◽  
Elisabetta Cerudelli ◽  
Maria Gazzilli ◽  
Raffaele Giubbini ◽  
...  

Background: Radiolabeled prostate-specific membrane antigen PSMA-based PET/CT or PET/MRI is a whole-body imaging technique currently performed for the detection of prostate cancer lesions. PSMA has been also demonstrated to be expressed by the neovasculature of many other solid tumors. Objective: The aim of this review is to evaluate the possible diagnostic role of radiolabeled PSMA PET/CT or PET/MRI in patients with gliomas and glioblastomas, by summarizing the available literature data. Methods: A comprehensive literature search of the PubMed/MEDLINE, Scopus, Embase and Cochrane library databases was conducted to find relevant published articles about the diagnostic performance of radiolabeled PSMA binding agents in PET/CT or PET/MRI imaging of patients with suspected gliomas or glioblastomas. Results: Seven case reports or case series and 3 studies enrolling more than 10 patients showed that gliomas and glioblastoma are PSMA-avid tumors. Conclusion: Radiolabeled PSMA imaging seems to be useful in analyzing glioma/glioblastoma. Further studies enrolling a wider population are needed to clarify the real clinical and diagnostic role of radiolabeled PSMA in this setting and its possible position in the diagnostic flow-chart.


2018 ◽  
Vol 29 (3) ◽  
pp. 1221-1230 ◽  
Author(s):  
Eva Dyrberg ◽  
Helle W. Hendel ◽  
Tri Hien Viet Huynh ◽  
Tobias Wirenfeldt Klausen ◽  
Vibeke B. Løgager ◽  
...  

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 144-144
Author(s):  
Martin Boegemann ◽  
Axel Semjonow ◽  
Hans-Joerg Breyholz ◽  
Andres Jan Schrader ◽  
Laura-Maria Krabbe ◽  
...  

144 Background: Recently developed 68Ga labeled prostate specific membrane antigen (PSMA) ligands were introduced as diagnostic tools to detect prostate cancer (PCa), PCa relapse and metastases with high accuracy. In this study we assessed the usability of preoperative PSMA-PET/CT information on congruency of spread of PCA compared with postoperative PCa-maps derived from radical prostatectomy (RPE) specimens. Methods: We referred 6 patients with biopsy proven high risk PCa to PSMA-PET/CT prior to RPE. Whole body PET/CT (Biograph mCT with 128 slice CT, Siemens) was performed 62±8 minutes after injection of 160±31 MBq [68Ga]-PSMA-HBED-CC (DKFZ-Ga-PSMA-11) as described by routine acquisition protocol. After RPE, prostate specimens were processed in the local pathology department. Topographical analysis of extension of PCa was reconstructed from representative slides on a schematic diagram resulting in a PCa-map of the prostate. After aligning the cutting planes of the PSMA-PET/CT to the PCa-map we defined 20 segments of the prostate and the seminal vesicles. We measured the maximum standard uptake value (SUV) of PSMA activity of the respective segments and compared the concordance of PSMA-positive and -negative areas with those of PCa and no PCa on the PCa-maps. We calculated sensitivity, specificity, positive and negative likelihood ratios (LR) taking available segments into account. Results: 106/112 segments were analyzed. 8 segments were excluded due to spillover of PSMA-activity in bladder urine. All but 3 segments with no PCa on the PCa-maps showed no uptake in PSMA-PET/CT (Specificity = 92%). The sensitivity of PSMA-PET/CT for showing PCa areas was equally 92%. The positive and negative LR for PSMA-PET/CT detecting or ruling out PCa was 11.5 and 0.09, respectively. Conclusions: This preliminary proof of concept study shows that prediction of later pathologic results in RPE-specimens could be estimated by preoperative PSMA-PET/CT. With optimized acquisition protocols it may be possible to improve our preliminary results. Perspectively PSMA-PET/CT may be helpful for identifying PCa suspicious lesions prior to prostate biopsy and support decision making prior to RPE or radiation therapy.


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