Comparison between pelvic PSMA-PET/MR and whole-body PSMA-PET/CT for the initial evaluation of prostate cancer: a proof of concept study

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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Evaluation of whole-body tumor burden with 68Ga-PSMA PET/CT in the biochemical recurrence of prostate cancer

Annals of Nuclear Medicine ◽

10.1007/s12149-019-01342-z ◽

2019 ◽

Vol 33 (5) ◽

pp. 344-350 ◽

Cited By ~ 4

Author(s):

A. E. T. Brito ◽

F. A. Mourato ◽

R. P. M. de Oliveira ◽

A. L. G. Leal ◽

P. J. A. Filho ◽

...

Keyword(s):

Prostate Cancer ◽

Biochemical Recurrence ◽

Tumor Burden ◽

Whole Body ◽

Psma Pet ◽

Pet Ct

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Correlations between whole body volumetric parameters of 68Ga-PSMA PET/CT and biochemical-histopathological parameters in castration-naive and resistant prostate cancer patients

Annals of Nuclear Medicine ◽

10.1007/s12149-021-01594-8 ◽

2021 ◽

Vol 35 (5) ◽

pp. 540-548

Author(s):

Özgen Ahmet Yildirim ◽

Cihan Gündoğan ◽

Canan Can ◽

Kerem poyraz ◽

Erkan Erdur ◽

...

Keyword(s):

Prostate Cancer ◽

Cancer Patients ◽

Whole Body ◽

Psma Pet ◽

Pet Ct

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Intraindividual Comparison of18F-PSMA-1007 PET/CT, Multiparametric MRI, and Radical Prostatectomy Specimens in Patients with Primary Prostate Cancer: A Retrospective, Proof-of-Concept Study

Journal of Nuclear Medicine ◽

10.2967/jnumed.116.189233 ◽

2017 ◽

Vol 58 (11) ◽

pp. 1805-1810 ◽

Cited By ~ 33

Author(s):

Claudia Kesch ◽

Maria Vinsensia ◽

Jan P. Radtke ◽

Heinz P. Schlemmer ◽

Martina Heller ◽

...

Keyword(s):

Prostate Cancer ◽

Radical Prostatectomy ◽

Multiparametric Mri ◽

Proof Of Concept ◽

Concept Study ◽

Intraindividual Comparison ◽

Primary Prostate Cancer ◽

Pet Ct

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Radiomics for detecting prostate cancer bone metastases invisible in CT: a proof-of-concept study

European Radiology ◽

10.1007/s00330-021-08245-6 ◽

2021 ◽

Author(s):

Ricarda Hinzpeter ◽

Livia Baumann ◽

Roman Guggenberger ◽

Martin Huellner ◽

Hatem Alkadhi ◽

...

Keyword(s):

Prostate Cancer ◽

Bone Metastases ◽

Classification Accuracy ◽

Reduction Process ◽

Training Dataset ◽

Pelvic Bone ◽

Body Region ◽

Proof Of Concept ◽

Concept Study ◽

Psma Pet

Abstract Objectives To investigate, in patients with metastatic prostate cancer, whether radiomics of computed tomography (CT) image data enables the differentiation of bone metastases not visible on CT from unaffected bone using 68 Ga-PSMA PET imaging as reference standard. Methods In this IRB-approved retrospective study, 67 patients (mean age 71 ± 7 years; range: 55–84 years) showing a total of 205 68 Ga-PSMA-positive prostate cancer bone metastases in the thoraco-lumbar spine and pelvic bone being invisible in CT were included. Metastases and 86 68 Ga-PSMA-negative bone volumes in the same body region were segmented and further post-processed. Intra- and inter-reader reproducibility was assessed, with ICCs < 0.90 being considered non-reproducible. To account for imbalances in the dataset, data augmentation was performed to achieve improved class balance and to avoid model overfitting. The dataset was split into training, test, and validation set. After a multi-step dimension reduction process and feature selection process, the 11 most important and independent features were selected for statistical analyses. Results A gradient-boosted tree was trained on the selected 11 radiomic features in order to classify patients’ bones into bone metastasis and normal bone using the training dataset. This trained model achieved a classification accuracy of 0.85 (95% confidence interval [CI]: 0.76–0.92, p < .001) with 78% sensitivity and 93% specificity. The tuned model was applied on the original, non-augmented dataset resulting in a classification accuracy of 0.90 (95% CI: 0.82–0.98) with 91% sensitivity and 88% specificity. Conclusion Our proof-of-concept study indicates that radiomics may accurately differentiate unaffected bone from metastatic bone, being invisible by the human eye on CT. Key Points • This proof-of-concept study showed that radiomics applied on CT images may accurately differentiate between bone metastases and metastatic-free bone in patients with prostate cancer. • Future promising applications include automatic bone segmentation, followed by a radiomics classifier, allowing for a screening-like approach in the detection of bone metastases.

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Clinical impact of whole-body 68Ga-PSMA I&T PET/CT: lesion frequency and added benefit in lower extremities

Nuklearmedizin ◽

10.1055/a-1542-6064 ◽

2021 ◽

Vol 60 (06) ◽

pp. 417-424

Author(s):

Lara Franziska Stolzenbach ◽

Florian Löcherbach ◽

Tobias Maurer ◽

Christoph Berliner ◽

Katharina Wargenau ◽

...

Keyword(s):

Prostate Cancer ◽

Lower Extremities ◽

Whole Body ◽

Newly Diagnosed ◽

Castration Resistant Prostate Cancer ◽

Systematic Analysis ◽

Castration Resistant ◽

Positron Emission ◽

Psma Pet ◽

Pet Ct

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.

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Validation of Postoperative Angiofibroma Radionuclide Imaging Study (PARIS) Protocol Using PSMA PET/CT—A Proof of Concept Study

Clinical Nuclear Medicine ◽

10.1097/rlu.0000000000003516 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Alok Thakar ◽

Pirabu Sakthivel ◽

Sreedharan Thankarajan Arunraj ◽

Ashu Seith Bhalla ◽

Arun Prashanth ◽

...

Keyword(s):

Radionuclide Imaging ◽

Imaging Study ◽

Proof Of Concept ◽

Concept Study ◽

Psma Pet ◽

Pet Ct

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18F-DCFPyL PSMA PET imaging compared to conventional imaging in the detection of pelvic nodal metastases in patients with locally advanced or oligometastatic prostate cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.6_suppl.36 ◽

2021 ◽

Vol 39 (6_suppl) ◽

pp. 36-36

Author(s):

Ashanda Rosetta Patrice Esdaille ◽

Edward Lawrence ◽

Christos Kyriakopoulos ◽

Brian Johnson ◽

Alejandro Roldán-Alzate ◽

...

Keyword(s):

Prostate Cancer ◽

Lymph Node ◽

Pet Imaging ◽

Locally Advanced ◽

Whole Body ◽

Conventional Imaging ◽

Psma Pet ◽

Pet Ct ◽

Oligometastatic Prostate Cancer ◽

The Mean

36 Background: Interest has arisen in the use of prostate specific membrane antigen (PSMA) PET/CT imaging to detect prostate cancer at metastatic sites using different tracers. Here, we examined the ability of 18F-DCFPyL (DCFPyL) PSMA-based PET imaging to detect nodal disease in comparison to conventional imaging in a cohort of men with locally advanced or oligometastatic prostate cancer (PC). Methods: UW17009 is an IRB-approved open-label, single-arm trial that enrolled 26 patients with newly diagnosed advanced PC. Patients received androgen deprivation therapy and docetaxel for 3 months followed by radical prostatectomy (RP) and pelvic lymph node dissection (PLND). Exploratory interventions include PSMA PET/CT and MRI imaging as a method for determining treatment response and heterogeneity in primary PC and metastatic lesions performed before and after chemohormonal therapy. Prior to randomization, patients received DCFPyL PET/CT and PET/MR imaging as well as CTs and Bone Scans. A mean dose of 7.86 mCi DCFPyL was administered. Whole-body PET/CT images were acquired starting at approximately 60 minutes after radiotracer injection followed by dedicated pelvic PET/MR and whole-body PET/MR. PET imaging findings were compared to conventional dedicated CT imaging and were correlated to the results of final pathologic examination of each pelvic nodal dissection. Results: 26 patients underwent conventional and exploratory imaging with subsequent neoadjuvant treatment, RP and PLND. The mean diagnostic PSA was 32.1 ng/dl and 88.5% had Gleason 9 PCa. Using conventional imaging, pelvic nodal disease was identified in 6/26 patients. Pelvic lymph node uptake was identified in 12/26 patients using DCFPyL-based PSMA PET. Initial correlation of the pathologic specimens with pretreatment PSMA PET imaging revealed pelvic nodal metastatic PC in 10/12(83%) patients. On a per-lymph node packet basis (6 per patient), there were 156 evaluable regions, including 65 from patients with positive nodes. PSMA detected 14 packets that were positive for PC and 102 packets that were negative on imaging and final pathology. PC was missed in 5 packets. The mean tumor size in the missed nodes was 2.3 mm(range 1-4 mm). Calculated sensitivity was 73.7%(95% CI [48.8, 90.8]), 85.7 % specificity(95% CI[78.1, 91.4]), and 95.3 % negative predictive value(95% CI[90.5, 97.7]). Conclusions: In comparison to conventional imaging, in this cohort, DCFPyL PSMA-based PET imaging identified nodal positive disease at twice the rate and when evaluating on a per-packet basis, there was high negative predictive value. Ongoing analysis of post-chemohormonal therapy PET imaging may provide more information regarding tumor response in this cohort.

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