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Prostate cancer is the second most common cancer in men. Its diagnosis and management are still challenging as both PSA levels and imaging have had their limitations. Prostate specific membrane antigen (PSMA) is aprostate specific cell surface protein and has been emerging as a novel target for PET imaging of prostate cancer. 68Ga PSMA PET-CT imaging have been shown as a better imaging technology in primary prostate cancer and at the same time detecting lymph node and bone metastases even in low PSA levels. Moreover, its counterpart 177 Lu PSMA has a great prospectto be used for the treatment of castration resistantprostate cancer. Bangladesh J. Nuclear Med. 22(1): 53-57, Jan 2019

The aim of the study was to retrospectively evaluate the recurrence detection rate of Gallium-68-prostate-specific membrane antigen [(68Ga)PSMA] imaging and therapy (IT by contrast, bicalutamide and MAB were not found as significant factors. In the present study, (68Ga)PSMA I&T was found to be quite successful in determining lesions in the biochemical recurrence, which is consistent with the findings of other I&T studies and studies conducted with different PSMA ligands. Thus, it can be considered that the use of (68Ga)PSMA I&T will become increasingly common.

To determine the impact of Gallium-68-labled prostate-specific membrane antigen positron-emission tomography/computed tomography ([68Ga]PSMA PET/CT) on radiotherapy planning for primary disease, biochemical cancer relapse, and advanced disease of prostate cancer. A total of 106 patients with prostate cancer scheduled for radiation therapy underwent 120 [68Ga]PSMA PET/CT scans prior to radiotherapy treatment. In 20 cases, patients underwent [68Ga]PSMA PET/CT for primary therapy (PT), 75 cases were referred for biochemical relapse after surgery (RL), and 25 cases were intended for palliative treatment of localized metastases (MD). We retrospectively compared the impact of [68Ga]PSMA PET/CT on lesion detection and treatment decision to CT alone. [68Ga]PSMA PET/CT revealed a total of 271 positive lesions, whereas CT detected 86 lesions (32%). Overall, the radiotherapy regime was changed in 55 of 120 cases (46%) based on the higher detection rate of [68Ga]PSMA PET/CT: in 15% of cases with PT, in 43% of cases with RL, and in 44% of cases with MD. [68Ga]PSMA PET/CT is superior to CT alone for lesion detection in prostate cancer, thereby significantly impacting on radiotherapy planning for primary disease, biochemical cancer relapse, and advanced disease of prostate cancer.

A 67-year-old male patient had undergone total gastrectomy and Roux-en-Y eso-jejunostomy 3 years ago for the treatment of tubular adenocarcinoma located at the corpus of the stomach. The patient was diagnosed with Gleason score 8 (4+4) metastatic prostate cancer during the follow-up period and received hormone therapy. Owing to his elevated prostate-specific antigen levels (77 ng/mL), his clinician referred him gallium-68 (68Ga) prostate-specific membrane antigen 11 (PSMA) positron emission tomography/computed tomography (PET/CT) for restaging. PET/CT showed multiple 68Ga PSMA receptor-positive skeletal lesions and linear PSMA activity at the eso-jejunostomy junction. He was then referred to undergo 18fluorine-fluorodeoxyglucose (18F-FDG) PET/CT to screen for gastric carcinoma recurrence. PET/CT images demonstrated no 18F-FDG avid lesion. However, endoscopy and biopsy performed with samples from the eso-jejunostomy junction revealed superficial benign squamous epithelial fragments.

To investigate the superiority or contribution of 5th minute pelvic and 2nd hour whole body Gallium68-prostate-specific membrane antigen—HBED-CC [(68Ga)PSMA 11] Positron Emission Tomography/Computed Tomography (PET/CT) images to 1st hour imaging in patients with prostate cancer (PCa). A total of 63 patients diagnosed with PCa who underwent (68Ga)PSMA 11 PET/CT between April 2019 and June 2019 and who had 5th minute and 1st and 2nd hour images were included in the study. Early (5th minute) pelvic region and 1st and 2nd hour full body images were obtained from all patients. The regions of interest (ROI) were drawn from the background tissues and the physiological uptake sites in a way to include the same lesions from primary and metastatic lesions in all three imagings, and SUVmax values, and tumor-background ratio (TBR) were calculated. The mean age of the patients was 69.81 ± 8.78 (min/max: 51/91) years. In the 5th minute images, prostate gland and bed were easier to evaluate, because of low bladder activity. However, lymph node evaluation was more difficult due to high vascular activity. In the prostate gland, lymph nodes and bone metastases, both SUVmax values and TBR rates increased with time from the 5th minute (p

Background Magnetic resonance imaging (MRI) is the most important imaging modality in the diagnosis and follow-up of glial brain tumors. Objective The aim of our study is to determine the correlation between tumor grade, determined with postoperative pathological examination, and standard uptake value (SUV), a semi-quantitative parameter, in patients who underwent imaging 68Ga-PSMA with using PET/MR. Material-method Thirty-five out of 38 patients’ images whose pathology was consistent with glial tumor, 42 lesions from separate anatomic localizations or with higher activity uptake than the rest of the tumor were evaluated. SUV values measured on PET images and grade relationship were evaluated based on each lesion while mitosis, Ki-67 were evaluated for each patient. Results Grade, Ki-67, mitosis, necrosis and SUVmax/mean/peak were found statistically significant with moderate/high correlation. The parameter with the highest correlation coefficient was mitosis. (For SUVmax r = 0.64, p = 0). When Grade II and III were considered as the first group and IV as the second group, the cutoff values were found to be 2.3 for SUVmax, 0.21 for SUVmean and 0.63 for SUVpeak. In the diagnosis of HGG, PET’s sensitivity is higher than MRI but no statistically difference was found between specificities. Conclusion 68Ga PSMA PET imaging is found to be particularly useful in differentiating Grade IV glial tumors from other grades. This finding is thought to be important in the differentiation the relapse with postoperative tissue changes, which is an important problem in the follow-up.

A 63-year-old man, recently diagnosed with carcinoma of the prostate (Gleason's score 4+4), with serum prostate-specific antigen 189.2 ng/mL, underwent Ga PSMA PET/CT scan for pretreatment staging. The study revealed abnormal tracer uptake in the prostatic bed region, the pelvic, abdominal, and mediastinal lymph nodes and diffuse metastases to the bilateral lungs. The lung metastasis was proved to be metastatic adenocarcinoma from analysis of bronchoalveolar lavage.

Aim: To examine predictive markers for high detection rates of 68Ga PSMA-PET/CT in biochemical recurrence (BR) prostate cancer (PCa) patients with low PSA levels. Material and Method: This trial was planned as a retrospective single center study. Patients with BR prostat cancer were included. PSA levels of all patients were lower 2 μg/l. Results: Totally thirty-two men patients with BR PCa were included in this study. 18 (56.3%) patients underwent radical prostatectomy and 14 (43.7%) patients curative intense radiotherapy. The number of patients received adjuvant maximal androgen blokage (MAB) treatment was 15 (46.9%). Median PSA levels was calculated 1.03 μg/l 17 (53.1%) of patients had

Vasculitis is a multisystem disease characterized by inflammation with infiltration of leukocytes into the blood vessels. Giant cell arteritis (GCA) is the most common form of vasculitis that mostly affects medium- and large-sized arteries. 18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is increasingly used to diagnose inflammation of large arteries in GCA. Galium-68 prostate-specific membrane antigen (PSMA) PET/CT has a vital role in the assessment of patients with prostate cancer for recurrence and metastasis of the disease. Various benign and non-prostate malignant conditions may give rise to increased PSMA uptake. Herein, we demonstrate that PSMA uptake can be seen in GCA.

In this retrospective study, we compared the diagnostic value of 68Gallium prostate-specific membrane antigen positron emission tomography computed tomography ([68Ga]PSMA PET/CT) in primary staging of patients with high-risk prostate cancer (PCa), in comparison to CT, magnetic resonance imaging (MRI), and bone scans, and we explored its overall impact on patients’ management plan. Patients with pathological confirmation of PCa with high-risk disease were included in this study. Information on patient demographics, clinical and histopathological findings with Gleason score and initial prostate specific antigen PSA levels, and radiological findings for CT, MRI, bone scan, and [68Ga]PSMA PET/CT were retrieved. We stratified the concordance and discordance of each imaging modality on per-patient and per-lesion-site bases. Twenty-one patients with high-risk disease were included in this study. [68Ga]PSMA PET/CT revealed a significantly higher concordance rate (90 %) compared to the concordance rates of bone scan (75 %), MRI (73 %), and CT (60 %). [68Ga]PSMA PET/CT had a similar accuracy to MRI in detecting prostate lesions but a higher accuracy for suspicious pelvic lymph nodes (95.2 % vs. 80 %). It also superseded CT scan in detecting suspicious pelvic lymph nodes (95.2 % vs. 75 %) and extra-pelvic lymph nodes (100 % vs. 75 %), as well as bone lesions via bone scan (100 % vs. 62.5 %). [68Ga]PSMA PET/CT changed the management in 11 patients (52 %). [68Ga]PSMA PET/CT is an invaluable imaging modality in the assessment of primary high-risk PCa with great potential for the detection of lymph node spread and bone metastases that would impact the management plan.

Our aim was to evaluate the benefit of early (1 h post-injection (p.i.)) and late (3 h p.i.) [68Ga]PSMA-HBED-CC positron emission tomography (PET)/x-ray computed tomography (CT) imaging for detection of biochemical recurrence (BCR) of prostate cancer (PCa). Seventy patients with BCR of the PCa and prostate-specific antigen (PSA) levels of less than 2.0 μg/l were subjected to [68Ga]PSMA-HBED-CC PET (mean injected activity 180 MBq). While early imaging contained whole body scans, late imaging was confined to the pelvis and the lower abdomen. Uptake in suspicious lesions was analyzed by peak and maximum standardized uptake values (SUVpeak/max). Tumor-to-background ratios were calculated for all lesions in which the liver served as reference organ. The Wilcoxon matched-pair signed-rank test was used to compare the uptake in suspicious lesions between early and late imaging. Follow-up data were used to validate the existence of the additionally detected lesions. Forty-four of the 70 patients thus examined were interpreted as PSMA-positive in early and/or late scans while 26 remained without suspicion of PSMA tracer uptake. A total of 70 suspicious lesions were analyzed. Ten tumor-suspicious lesions from seven different patients were better or exclusively visible in the late measurements while three tumor-suspicious lesions from three different patients were better or exclusively visible in the early images. A validation by follow-up data was possible for 11 of these 13 additionally detected lesions. In direct comparison between early and late imaging, the mean SUVmax in PSMA-positive lesions was 74 % higher (p

Purpose Since the success of prostate-specific membrane antigen-positron emission tomography (PSMA-PET) imaging for patients with oligorecurrent prostate cancer (ORPC), it is increasingly used for radiotherapy as metastasis-directed therapy (MDT). Therefore, we developed a prognostic risk classification for biochemical relapse-free survival (bRFS) for patients after PSMA-PET-guided MDT after radical prostatectomy. Methods We analyzed 292 patients with local recurrence (LR) and/or pelvic lymph node (LN) lesions and/or up to five distant LN, bone (BM), or visceral metastases (VM) detected with [68Ga]PSMA-PET imaging. Median follow-up was 16 months (range 0–57). The primary endpoint was bRFS after MDT. Cox regression analysis for risk factors was incorporated into a recursive partitioning analysis (RPA) with classification and regression tree method. Results PSA at recurrence ≥ 0.8 ng/mL, BM, and VM was significantly associated with biochemical relapse. RPA showed five groups with tenfold cross-validation of 0.294 (SE 0.032). After building risk classes I to IV (p Conclusion We developed and internally validated a risk classification for bRFS after PSMA-PET-guided MDT. Patients with PSA

Background Current guidelines highlight the importance of accurate staging in the management and prognostication of high risk primary prostate cancer. Conventional radiologic imaging techniques are insufficient to reliably detect lymph node metastases in prostate cancer. Despite promising results, there is limited published data on the diagnostic accuracy of PSMA PET-CT to assess local nodal metastases prior to radical prostatectomy. This study aims to assess the diagnostic efficacy of 68Ga PSMA PET-CT in local lymph node staging of high risk primary prostate cancer when compared to histopathological findings following radical prostatectomy with pelvic lymph node dissection. Methods We retrospectively analysed consecutive patients with high risk primary prostate cancer referred by urologists for primary staging PSMA PET-CT using a 68Ga-labeled PSMA ligand, Glu-NH-CO-NHLys-(Ahx)-[HBEDD-CC], from October 2015 to October 2017. The scans of patients who underwent radical prostatectomy with pelvic lymph node dissection were interpreted by the consensus reading of two experienced nuclear medicine physicians blinded to clinical and histopathological data. The contemporaneous records of the referring urologists were retrospectively reviewed for noteworthy unexpected PET findings that altered their personal preference for surgical management. Results Seventy-one patients were recruited and analysed. PSMA PET-CT showed findings compatible with local disease in 47 patients (66.2%), lymph node metastases in 10 patients (14.1%) and distant metastases in 14 patients (19.7%). Twenty-eight patients (twenty-seven of whom had local disease only) underwent surgery yielding 214 lymph nodes, all of which were negative on histopathological analysis. On a node-based analysis, 213 of 214 lymph nodes were accurately identified as negative for disease with a negative predictive value of 100%. 11 patients had unexpected PET findings contemporaneously documented by urologists to alter their preference for surgical management. Conclusions PSMA PET-CT appears to have a high negative predictive value for local lymph node metastases in high risk primary prostate cancer when compared to histopathological findings following radical prostatectomy with pelvic lymph node dissection.

Purpose: Widely used in clinical practice, the maximum standardized uptake value (SUVmax) is a statistical index highly prone to physical and biological variations, which can lead to unpredictable errors. This study has a methodological aim: to identify a more robust SUV-based index representing the tracer accumulation. In particular, the new metric was tested to confirm the potential of mannitol to reduce renal uptake [68Ga] prostate-specific membrane antigen (68Ga-PSMA). Procedures: To this aim, our previously published work, proving the efficacy of mannitol, was considered as a background study. Renal SUVmax was calculated in nine patients undergoing 68Ga-PSMA positron emission tomography/computed tomography (68Ga-PSMA-PET/CT) at baseline (b-PET/CT) and at follow-up after intravenous infusion of 500 ml of 10% mannitol (m-PET/CT). SUV values of kidney volumes were extracted by a new 3D segmentation method. A new parameter, the median computed on the upper 10% of the SUV distribution (SUV95th), was introduced to better characterize the tracer accumulation. A comparison between SUVmax and SUV95th was also performed. Kruskal-Wallis test was used to assess the statistical significance of the differences in SUV95th between b-PET/CT and m-PET/CT. Results: SUV95th not only confirmed the efficacy of mannitol as demonstrated in the previous study but improved the separability of b-PET/CT and m-PET/CT examinations, overturning SUVmax findings in two cases. The outcomes of the Kruskal-Wallis test computed for each kidney proved that differences between b-PET/CT and m-PET/CT SUV95th values were significant (p-value

Positron emission tomography (PET) for prostate-specific membrane antigen (PSMA) represents a promising method for prostate cancer diagnosis and staging. Comparisons of PSMA-based tumour characterisation to multiparametric MRI (mpMRI) are limited, hence this study sought to compare the diagnostic accuracy of 68Ga-PSMA PET/CT to mpMRI against radical prostatectomy (RP) whole gland histopathology. A retrospective cohort study of consecutive patients who underwent pre-operative mpMRI and 68Ga-PSMA PET/CT followed by a RP was performed. Standard clinical parameters were collected. “Per patient” and “per lesion” analyses for image-based detection according to RP histopathology were described using sensitivity, specificity and other measures of diagnostic accuracy. Fifty-eight patients (median age 65.5 years, median PSA 7.35 ng/mL) underwent RP, resulting in a high-risk cohort (≥pT3 69%). Sensitivities for identification of index lesion, bilateral and multifocal disease were 90%, 21%, 19% for mpMRI and 93%, 42%, 34% for 68Ga-PSMA PET/CT. Histology analyses revealed 88 cancer foci of Gleason grades 3 + 3 (4%), 3 + 4 (64%), 4 + 3 (19%), 4 + 4 (3%) and ≥ 4 + 5 (10%), of which 68Ga-PSMA PET/CT correctly detected more foci (78%, AUC 0.817) than mpMRI (69%, AUC 0.729). 68Ga-PSMA PET/CT may better reflect RP histopathology compared to mpMRI when considering multifocal and bilateral disease. These findings may influence surgical planning, targeted biopsy and focal therapy strategies and require further research.

The aim of this study was to evaluate potential differences in “Glu-NH-CO-NH-Lys” radio-labeled with [68Ga]gallium N,N-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N-diacetic acid ([68Ga]PSMA-HBED-CC) uptake in osteolytic, osteoblastic, mixed, and bone marrow metastases in prostate cancer (PC) patients. This retrospective study was approved by the local ethics committee. Patients who received [68Ga]PSMA-HBED-CC positron emission tomography/computed tomography ([68Ga]PSMA-PET/CT) with at least one positive bone metastasis were included in this study. Only patients who have not received systemic therapy for their PC were included. Bone metastases had to be confirmed by at least one other imaging modality or follow-up investigation. The maximum standardized uptake value (SUVmax) and mean Hounsfield units (HUmean) of each metastasis were measured. Based on CT, each metastasis was classified as osteolytic (OL), osteoblastic (OB), bone marrow (BM), or mixed (M). One hundred fifty-four bone metastases in 30 patients were evaluated. Eighty out of 154 (51.9%) metastases were classified as OB, 21/154 (13.6%) as OL, 23/154 (14.9%) as M, and 30/154 (19.5%) as BM. The SUVmax for the different types of metastases were 10.6 ± 7.07 (OB), 24.0 ± 19.3 (OL), 16.0 ± 21.0 (M), and 14.7 ± 9.9 (BM). The SUVmax of OB vs. OL and OB vs. BM metastases differed significantly (p ≤ 0.025). A significant negative correlation between HUmean and SUVmax (r = −0.23, p

The aim of this study was to assess the value of dual-time point imaging in PET/CT for detection of biochemically recurrent or persistent prostate cancer, using the prostate-specific membrane antigen (PSMA) ligand [68Ga]PSMA I&T. 240 patients who underwent a [68Ga]PSMA I&T PET/CT in the context of biochemical relapse of prostate cancer were included in this retrospective analysis. Imaging consisted of a standard whole-body PET/CT (1 h p.i.), followed by delayed (3 h p.i.) imaging of the abdomen. PSA-stratified proportions of positive PET/CT results, standardized uptake values and target-to-background ratios were analyzed, and compared between standard and delayed imaging. The overall detection rates of [68Ga]PSMA I&T PET/CT were 94.2, 71.8, 58.6, 55.9 and 38.9% for PSA levels of ≥2, 1 to 0.2 to

Ga prostate-specific membrane antigen (PSMA) PET/CT is increasingly used to evaluate extent of disease in prostate carcinoma. Several other benign and malignant pathologies have also been reported to demonstrate PSMA avidity. We present a case of serous cystadenoma of the pancreas showing focal uptake on PSMA PET/CT.

Ga prostate-specific membrane antigen (PSMA) PET/CT is a new imaging technique that is significantly more sensitive to prostate cancer lesions than other conventional imaging modalities. Various other benign and malignant neoplasms may also express PSMA and show uptake on PSMA PET/CT scan. We report a case of 66-year-old man who had a PSMA PET/CT scan for restaging of prostate carcinoma. A PSMA-avid left femoral lymph node was identified. Subsequent biopsy confirmed the diagnosis of follicular lymphoma. It is important to be aware of this possibility to avoid scan misinterpretation. Biopsy of any atypical or clinically unexpected lesions should be considered.

Ga-PSMA PET/CT is a new imaging technique that is highly sensitive to metastatic prostate cancer lesions compared with other conventional imaging modalities. We report a case of a 77-year-old man with newly diagnosed prostate carcinoma who had a PSMA PET/CT scan for staging of his disease. An intensely PSMA-avid right pelvic mass was identified abutting the cecum and terminal ileum. Surgical removal and histopathologic examination of this lesion revealed the diagnosis of a desmoid tumor. It is important to be aware that many tumors other than prostate carcinoma may also show avid uptake on PSMA PET/CT scan.

To determine the detection rate of PET/CT in biochemical relapse of prostate cancer using [68Ga]PSMA I&T and to compare it with published detection rates of [68Ga]PSMA HBED-CC. We performed a retrospective analysis in 83 consecutive patients with documented biochemical relapse after prostatectomy. All patients underwent whole body [68Ga]PSMA I&T PET/CT. PET/CT images were evaluated for presence of local recurrence, lymph node metastases, and distant metastases. Proportions of positive PET/CT results were calculated for six subgroups with increasing prostate specific antigen (PSA) levels ( 0.05). [68Ga]PSMA I&T PET/CT has high detection rates of recurrent prostate cancer that are comparable to [68Ga]PSMA HBED-CC.

A 68-year-old man presented with right-side facial numbness. MRI showed an extra-axial mass infiltrating the right temporal bone. It was debulked surgically, and histopathology revealed metastatic adenocarcinoma. Ga PSMA PET/CT done in view of increased PSA levels and clinically suspicious hard lesion in prostate showed primary lesion in left side of prostate with metastases to the right temporal bone. Primary carcinoma of the prostate and metastases to the right temporal bone were proven histopathologically. Our case highlights the usefulness of Ga PSMA PET/CT in identifying the primary site in suspected prostate cancer and mapping the metastatic sites.

Head and neck paragangliomas are rare and often asymptomatic tumors and mostly present as painless masses. We describe 68Ga PSMA 11 PET/CT and 68Ga DOTANOC PET/CT findings of a 40 year old man with triple head and neck paragangliomas with emphasis on exploring the possible theranostic option

[68Ga]PSMA-HBED-CC PET/CT to differentiate between diffuse bone metastases of prostate cancer and osteopoikilosis

To investigate whether the numbers of lymph node metastases and coeliac ganglia delineated on [Ga-68]PSMA-HBED-CC PET/CT scans differ among datasets generated using different reconstruction algorithms.Data were constructed using the BLOB-OS-TF, BLOB-OS and 3D-RAMLA algorithms. All reconstructions were assessed by two nuclear medicine physicians for the number of pelvic/paraaortal lymph node metastases as well the number of coeliac ganglia. Standardized uptake values (SUV) were also calculated in different regions.At least one [Ga-68]PSMA-HBED-CC PET/CT-positive pelvic or paraaortal lymph node metastasis was found in 49 and 35 patients using the BLOB-OS-TF algorithm, in 42 and 33 patients using the BLOB-OS algorithm, and in 41 and 31 patients using the 3D-RAMLA algorithm, respectively, and a positive ganglion was found in 92, 59 and 24 of 100 patients using the three algorithms, respectively. Quantitatively, the SUVmean and SUVmax were significantly higher with the BLOB-OS algorithm than with either the BLOB-OS-TF or the 3D-RAMLA algorithm in all measured regions (p The results of [Ga-68]PSMA-HBED-CC PET/CT are affected by the reconstruction algorithm used. The highest number of lesions and physiological structures will be visualized using a modern algorithm employing time-of-flight information.

To assess whether clinical prostate cancer (PCA) related factors and therapy status can predict the degree of tracer uptake on [We retrospectively studied 124 patients with recurrent an/or metastatic PCA who underwent [Significant positive correlations between lesion size and SUVmax were found in pelvic lymph node metastases5 -≤15 mm (Spearmans rho = 0.502, p = 0.002) as well as in extrapelvic lymph node metastases5 mm (rho = 0.314, p = 0.033) and5 ≤-15 mm (rho = 0.614, p0.001). 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.Measured tracer uptake in [Signifikant positive Korrelationen zwischen Läsionsgröße und SUVmax wurden in pelvinen Lymphknotenmetastasen5 -≤15 mm (Spearmans rho = 0.502, p = 0.002), extrapelvinen Lymphknotenmetastasen5 mm (rho = 0.314, p = 0.033) und5 -≤15 mm (rho = 0.614, p0.001) gefunden. Für jede anatomische Lokalisation wurde ein höherer Wert SUVmax innerhalb der größten Kategorie verglichen zu mittleren und kleinsten Kategorie gefunden.ZIEL:: Beantwortung der Frage ob klinisch bestimmbare Faktoren und Therapiestatus bei Prostatakarzinom (PCA) eine Vorhersage zur Traceranreicherung in [Signifikant positive Korrelationen zwischen Läsionsgröße und SUVmax wurden in pelvinen Lymphknotenmetastasen5 -≤15 mm (Spearmans rho = 0.502, p = 0.002), extrapelvinen Lymphknotenmetastasen5 mm (rho = 0.314, p = 0.033) und5 -≤15 mm (rho = 0.614, p0.001) gefunden. Für jede anatomische Lokalisation wurde ein höherer Wert SUVmax innerhalb der größten Kategorie verglichen zu mittleren und kleinsten Kategorie gefunden.

The aim of this study was to determine the physiological and pathophysiological biodistribution of [(68)Ga]PSMA-HBED-CC (PSMA-11) ([(68)Ga]PSMA) in patients with prostate cancer (PCA) to establish the range of normal uptake in relevant organs and primary prostate tumours, locally recurrent PCA, lymph and bone metastases and other metastatic lesions. Additionally, we aimed to determine a cut-off uptake value for differentiation of primary tumours from normal prostate tissue.Overall, [(68)Ga]PSMA positron emission tomography/x-ray computed tomography (PET/CT) of 101 patients (mean age 69.1 years) with PCA was analysed retrospectively. For assessment of tracer biodistribution, maximum standardized uptake values (SUVmax) were calculated for various normal organs, as well as for primary tumours (PT) and/or metastases. Results are presented as median, interquartile range (IQR; 25th quantil-75th quantil) and range (minimum-maximum).[(68)Ga]PSMA PET/CT was performed 50 min (range 30-126) after injection of 109 MBq (range 84-158). Regarding biodistribution, highest uptake (median/IQR/range) of the tracer was found in the kidneys (49.6/40.7-57.6/2.7-97.0) followed by the submandibular glands (17.3/13.7-21.2/7.5-30.4), parotid glands (16.1/12.2-19.8/5.5-30.9) and duodenum (13.8/10.5-17.2/5.8-26.9). The best cut-off value for differentiating physiological uptake in the primary tumour from that in the prostate was found to be an SUVmax of 3.2. The median SUVmax in the PT (n = 35), locally recurrent PCA (n = 8), lymph node (n = 166), bone (n = 157) and other metastases (n = 3) were 10.2, 5.9, 6.2, 7.4 and 3.8, respectively. The best cut-off values for differentiating non-pathological uptake in lymph nodes and bones from tumour uptake were found to be SUVmax of 3.2 and 1.9, respectively. Patients with PSA2 had significantly lower SUVmax in bone metastases as compared to patients with PSA ≥2 (p 0.01).This biodistribution study provided a broad range of uptake data of [(68)Ga]PSMA-11 for normal organs/tissues, primary prostate tumours and metastatic lesions based on a large patient cohort. Both PT and small metastatic lesions were detectable due to their high tracer uptake. Four-times-higher median uptake in PT in comparison to normal prostate stroma resulted in a high diagnostic accuracy that could potentially be used for multimodal image-guided biopsy with dedicated reconstruction software.

An 85-year-old man with prostate cancer for metastatic workup underwent Gallium Prostate-Specific Membrane Antigen (Ga-PSMA) PET/CT (Ga-PSMA PET/CT), which revealed unusual tracer uptake in the shaft and glans of penis as well as multiple systemic metastases in liver, skeletal, and lymph nodes. The penile lesion was proved to be metastatic adenocarcinoma from prostate on fine needle aspiration cytology. The patient underwent Lutetium (Lu)-labeled PSMA radioligand therapy, which also revealed diffuse tracer uptake in the penile shaft as well as other metastatic sites.

Purpose To examine the relationship between the extent of disease determined by [Ga-68]PSMA-HBED-CC-PET/CT and the important clinical measures prostate-specific antigen (PSA), PSA doubling time (PSAdt) and Gleason score. Methods We retrospectively studied the first 155 patients with recurrent prostate cancer (PCA) referred to our university hospital for [Ga-68]PSMA-HBED-CC PET/CT. Results PET/CT was positive in 44 %, 79 % and 89 % of patients with PSA levels of = 2 ng/ml, respectively. Patients with high PSA levels showed higher rates of local prostate tumours (p

68Ga-prostate-specific membrane antigen (PSMA) PET/CT imaging is a relatively new imaging technique used to evaluate the extent of disease in prostate carcinoma. Various other neoplasms may also express PSMA and show uptake on PSMA PET/CT scan. We report a case of a 62-year-old man who had a PSMA PET/CT scan for restaging of prostate carcinoma. A PSMA-avid thyroid lesion was identified, and subsequent tissue sampling confirmed the diagnosis of follicular thyroid adenoma. It is important to be aware of this possibility to avoid scan misinterpretation. Tissue biopsy of PSMA-avid thyroid lesions should be considered to exclude a primary thyroid neoplasm.

The successful use of theranostic twins in neuroendocrine tumors (NET) is the pioneering approach to radionuclide therapy in other tumor types. 64Cu/18F PSMA for molecular imaging with PET-CT and peptide radioligand therapy (PRLT) with 177Lu labeled PSMA inhibitors are the next theranostic twins in nuclear medicine. 68Ga/ 64Cu/18F PSMA PET-CT detects metastatic prostate cancer with high diagnostic sensitivity and specificity and can be used to select patients for PRLT and evaluate therapy response. Radionuclide therapy with 177Lu-PSMA inhibitors has been shown to be effective in the treatment of metastatic CRPC.

Aim: PSMA expression has been observed in increased levels in patients with high Gleason scores. Current information on Ga-68 PSMA PET/CT shows that primary staging with PET/CT is important in patients with high-risk PC. Ga-68 PSMA PET/CT may also have a place in patients with intermediate risk PC, but only a few data are available at present. In this study, we aimed to elucidate the relationship between PSMA expression value in the prostate gland, total PSA levels and GS in patients diagnosed with prostate cancer. Material and Method: A total of 98 patients who were pathologically diagnosed with prostate cancer that did not receive any treatment and underwent Ga‐68 PSMA PET/CT imaging for staging were included in the study. Findings detected in Ga‐68 PSMA PET/CT imaging were categorized as prostate, lymph node, bone, and visceral organ. The focal increased PSMA expression values ​​observed in the prostate gland were recorded as SUVmax. The patients were divided into two separate groups according to their GS score (GS>7 and GS≤7). Correlations between prostate PSMA SUVmax, GS score and total PSA scores were investigated. Results: PSMA SUVmax levels of the group with a Gleason score of >7 were found to be significantly higher than the group with a Gleason score of ≤7 (p=0.03). The rates of lymph node metastasis, bone metastasis and visceral organ metastases were found to be significantly higher in the group with a Gleason score >7 compared to the group with a Gleason score ≤7. A positive correlation was observed between PSMA SUVmax and Total PSA (r=0.260, p=0.01). A positive correlation was observed between PSMA SUVmax and Gleason score (r=0.260, p=0.01). A positive correlation was observed between total PSA and Gleason score (r=0.320, p=0.001). Conclusion: In conclusion, PSMA SUVmax and Total PSA levels were higher in the group with high Gleason score. There is a positive correlation between PSMA SUVmax and total PSA. Clinicians should be careful in this regard, as the possibility of metastasis will be high in groups with high Gleason scores.

PURPOSE Isolated case reports mention the uptake of radiolabeled PSMA in lymphoma. However, it is not clear if the intensity of 68Ga-PSMA expression varies among different histological subtypes or if it correlates with 18F-FDG uptake. This study compared both tracers in patients with diverse lymphoma subtypes. METHODS Ten patients with biopsy-proven-lymphoma underwent 18F-FDG and 68Ga-PSMA-PET/CT (maximum time interval: 6 days). Lymphoma subtypes included Hodgkin's lymphoma (HL, three patients) and aggressive and indolent non-Hodgkin's lymphoma (NHL, seven patients). The intensity of PSMA uptake was classified visually as low, intermediate, or high, using blood pool, liver and parotid gland uptake as references. Maximum standardized-uptake value (SUVmax) of each affected site was measured in both sets of images. RESULTS FDG detected 59/59 involved sites in 10 patients and PSMA 47/59 sites in nine patients. PSMA uptake was generally low, regardless of the intensity of FDG uptake, but it was classified as intermediate in two patients. The median SUVmax varied from 2.0 (2.0-8.2) to 30.9 for FDG and from 1.7 (1.7-1.7) to 4.4 for PSMA, P < 0.0001. The primary lesion of one patient had a marked intralesional mismatch uptake pattern of the tracers, with areas of higher PSMA expression than FDG uptake, and vice-versa. A brain lesion was more easily identified with PSMA than with FDG images. CONCLUSION HL and several NHL subtypes may present PSMA uptake. The intensity of PSMA expression is generally lower than that of FDG uptake and seems to present less variation among the different histological subtypes of lymphomas.

OBJECTIVE The aim of this study was to evaluate the relationship between volumetric parameters calculated using semiautomatic quantification of lesions detected in 68Ga-labeled prostate-specific membrane antigen PET-computed tomography (68Ga-PSMA PET/CT) and clinical characteristics in prostate cancer (PCa) patients with biochemical recurrence. METHODS A total of 85 consecutive PCa patients with biochemical recurrence who underwent 68Ga-PSMA PET/CT at our institution from January 2019 to March 2020 were retrospectively assessed. 68Ga-PSMA PET/CT-derived volumetric parameters, including whole-body PSMA tumor volume (wbPSMA-TV) and whole-body total lesion PSMA (wbTL-PSMA), as well as the established maximum and mean standardized uptake value (SUVmax and SUVmean), were calculated for each patient. All PET-derived parameters were analyzed for correlation with prostate-specific antigen (PSA) levels and for association with Gleason scores. RESULTS Eighty-five patients with a mean age of 68.9 ± 7.8 years (range, 47-83 years) and a mean PSA level of 40.9 ± 92.1 ng/ml (range, 0.2-533.2 ng/ml) were analyzed. Volumetric parameters, that is, wbPSMA-TV and wbTL-PSMA, demonstrated a statistically significant correlation with PSA levels (r = 0.403 and r = 0.556, respectively, all at P < 0.001) and only the means of wbTL-PSMA were significantly different between the Gleason score groups (P < 0.05). CONCLUSIONS The results of our study indicate that 68Ga-PSMA PET/CT might be a valuable tool for the detection and follow-up of recurrence in PCa patients. 68Ga-PSMA PET/CT-derived quantitative volumetric parameters demonstrated a highly significant correlation with changes in PSA levels. Larger prospective studies are needed to help reveal the full potential of parameters such as PSMA-TV and TL-PSMA derived from PET imaging with 68Ga-PSMA.

Objectives To develop and examine a scoring system in metastatic castration-resistant prostate carcinoma (mCRPC) that integrates findings of both 68Ga-prostate-specific membrane antigen (PSMA) and flurodeoxyglucose (FDG) PET-CT imaging in a single combined parameter and referred to as the 'Pro-PET' score. Methods A six-tier integrated dual tracer PET-CT (68Ga-PSMA and FDG) Image Scoring System ('Pro-PET' score) was conceptualized, based on the findings of both 68Ga-PSMA-11 and FDG PET-CT in patients of mCRPC. This proposed integrated scoring was examined in a retrospective analytical study assessing mCRPC patients (n = 47) referred for 177Lu-PSMA-617 peptide receptor radioligand therapy (PRLT) and had both FDG and 68Ga-PSMA PET-CT undertaken within 15 days of each other without any interim treatment intervention. The 'Pro-PET' score grades and subgrades were assigned and compared with clinical data, such as histopathology, Gleason score, serum prostate-specific antigen (PSA), treatment response (symptomatic, biochemical, metabolic and anatomical) and survival [overall survival (OS) and progression-free survival (PFS)]. Results The Pro-PET score significantly correlated with symptomatic (P = 0.05), biochemical (P = 0.05), metabolic (P = 0.001) and anatomical (P = 0.012) responses, PFS (P = 0.03) and OS (P = 0.027). On multivariate analysis, histopathology, Gleason score and PSA as individual parameters were not significantly associated with OS and PFS, whereas the Pro-PET score was found to have a significant association (P = 0.001 for PFS and 0.011 for OS). Conclusion The 'Pro-PET' scoring system integrating dual tracer PET-CT imaging findings in a single parameter appeared as a potentially promising prognostic marker that has the potential to enhance the objectivity and scientific basis of prostate carcinoma theranostics and prognostication.

A 43-year-old man diagnosed with fibrous dysplasia with McCune-Albright syndrome was subjected to 18F-fluoride bone scan and 68Ga-PSMA-HBED-CC PET/CT as per the institution protocol. 18F-bone scan revealed extensive involvement of axial and appendicular skeleton confirming polyostotic fibrous dysplasia. 68Ga-PSMA PET/CT showed increased tracer uptake in corresponding lesions of fibrous dysplasia. PSMA uptake in fibrous dysplasia lesions has been rarely described with literature evidence being limited to anecdotal case reports. Nevertheless, due to increasing use of PSMA PET/CT, one should be aware of this false-positive finding to avoid misinterpretation of the scans.

Contains fulltext : 235315.pdf (Publisher’s version ) (Closed access) PURPOSE: This study proposes optimal tracer-specific threshold-based window levels for PSMA PET-based intraprostatic gross tumour volume (GTV) contouring to reduce interobserver delineation variability. METHODS: Nine (68)Ga-PSMA-11 and nine (18)F-PSMA-1007 PET scans including GTV delineations of four expert teams (GTV(manual)) and a majority-voted GTV (GTV(majority)) were assessed with respect to a registered histopathological GTV (GTV(histo)) as the gold standard reference. The standard uptake values (SUVs) per voxel were converted to a percentage (SUV%) relative to the SUV(max). The statistically optimised SUV% threshold (SOST) was defined as those that maximises accuracy for threshold-based contouring. A leave-one-out cross-validation receiver operating characteristic (ROC) curve analysis was performed to determine the SOST for each tracer. The SOST analysis was performed twice, first using the GTV(histo) contour as training structure (GTV(SOST-H)) and second using the GTV(majority) contour as training structure (GTV(SOST-MA)) to correct for any limited misregistration. The accuracy of both GTV(SOST-H) and GTV(SOST-MA) was calculated relative to GTV(histo) in the 'leave-one-out' patient of each fold and compared with the accuracy of GTV(manual). RESULTS: ROC curve analysis for (68)Ga-PSMA-11 PET revealed a median threshold of 25 SUV% (range, 22-27 SUV%) and 41 SUV% (40-43 SUV%) for GTV(SOST-H) and GTV(SOST-MA), respectively. For (18)F-PSMA-1007 PET, a median threshold of 42 SUV% (39-45 SUV%) for GTV(SOST-H) and 44 SUV% (42-45 SUV%) for GTV(SOST-MA) was found. A significant pairwise difference was observed when comparing the accuracy of the GTV(SOST-H) contours with the median accuracy of the GTV(manual) contours (median, - 2.5%; IQR, - 26.5-0.2%; p = 0.020), whereas no significant pairwise difference was found for the GTV(SOST-MA) contours (median, - 0.3%; IQR, - 4.4-0.6%; p = 0.199). CONCLUSIONS: Threshold-based contouring using GTV(majority)-trained SOSTs achieves an accuracy comparable with manual contours in delineating GTV(histo). The median SOSTs of 41 SUV% for (68)Ga-PSMA-11 PET and 44 SUV% for (18)F-PSMA-1007 PET form a base for tracer-specific window levelling. TRIAL REGISTRATION: Clinicaltrials.gov ; NCT03327675; 31-10-2017.

Purpose Currently, approximately 11–38% of prostate cancer (PCa) patients undergoing radical prostatectomy have a positive surgical margin (PSM) on histopathology. Cerenkov luminescence imaging (CLI) using 68Ga-prostate-specific membrane antigen (68Ga-PSMA) is a novel technique for intraoperative margin assessment. The aim of this first-in-man study was to investigate the feasibility of intraoperative 68Ga-PSMA CLI. In this study, feasibility was defined as the ability to distinguish between a positive and negative surgical margin, imaging within 45 min and low radiation exposure to staff. Methods Six patients were included in this ongoing study. Following perioperative i.v. injection of ~ 100 MBq 68Ga-PSMA, the prostate was excised and immediately imaged ex vivo. Different acquisition protocols were tested, and hotspots on CLI images from the intact prostate were marked for comparison with histopathology. Results By using an acquisition protocol with 150 s exposure time, 8 × 8 binning and a 550 nm shortpass filter, PSMs and negative surgical margins (NSMs) were visually correctly identified on CLI in 3 of the 5 patients. Two patients had a hotspot on CLI from cancer Conclusion Overall, the study showed that 68Ga-PSMA CLI is a feasible and low-risk technique for intraoperative margin assessment in PCa. The remaining patients in this ongoing study will be used to assess the diagnostic accuracy of the technique. Trial registration: NL8256 registered at www.trialregister.nl on 04/11/20109.