Impact of 68Ga-PSMA-11 PET staging on clinical decision-making in patients with intermediate or high-risk prostate cancer

Prostate-specific Membrane Antigen: Diagnostics

Since its clinical introduction in May 2011, prostate-specific membrane antigen (PSMA)-PET/computed tomography has quickly gained worldwide recognition as a significant breakthrough in prostate cancer diagnostics. In the meantime, several new PSMA radioligands for PET imaging have been introduced into routine clinical practice. This article aims to introduce the most commonly used tracers and their key areas of application.

Fluorine-18 prostate-specific membrane antigen-1007-avid indeterminate bone lesions in prostate cancer: clinical and PET/CT features to predict outcomes and prognosis

AIM

To determine clinical and fluorine-18 prostate-specific membrane antigen-1007 (18F-PSMA-1007) integrated positron-emission tomography (PET)/computed tomography (CT) features that could be used to interpret indeterminate bone lesions (IBLs) and assess the prognosis of prostate cancer (PCa) in patients with IBLs.

MATERIALS AND METHODS

Consecutive patients who underwent PSMA PET/CT were analysed retrospectively. IBLs were identified as benign or malignant based on follow-up imaging and clinical management. Lesion- and patient-based assessments were performed to define features predictive of bone lesion results and determine clinical risk. Patients' prognosis was analysed based on clinical characteristics, including prostate-specific antigen (PSA) and alkaline phosphatase (ALP), respectively.

RESULTS

A total of 105 patients (mean age ± SD, 72.1 ± 8 years) were evaluated and 158 IBLs were identified. Fifty-three (33.5%), 36 (22.8%), and 69 (43.7%) IBLs were benign, malignant, and equivocal, respectively. Variables including location, maximum standard uptake value (SUVmax), and lymph node metastases (LNM) were related to the benignancy or malignancy of IBLs (p=0.046, p<0.001 and p<0.001, respectively). Regression analysis indicated that LNM, SUVmax, and location of IBLs could be predictors of lesion interpretation (p<0.001, p=0.002 and p=0.035). Patients with benign IBLs experienced the most considerable decreases in PSA and ALP levels.

CONCLUSIONS

LNM, SUVmax, and location may contribute to IBL interpretation. A rapid decrease in PSA and ALP levels might suggest a better prognosis for patients with benign IBLs.

18 F-prostate specific membrane antigen positron emission tomography/computerized tomography for lymph node staging in medium/high risk prostate cancer: A systematic review and meta-analysis

BACKGROUND

Lymph node staging of prostate cancer (PCa) is important for planning and monitoring of treatment. 18 F-prostate specific membrane antigen positron emission tomography/computerized tomography ( 18 F-PSMA PET/CT) has several advantages over 68 Ga-PSMA PET/CT, but its diagnostic value requires further investigation. This meta-analysis focused on establishing the diagnostic utility of 18 F-PSMA PET/CT for lymph node staging in medium/high-risk PCa.

METHODS

We searched the EMBASE, PubMed, Cochrane library, and Web of Science databases from inception to October 1, 2022. Prostate cancer, 18 F, lymph node, PSMA, and PET/CT were used as search terms and the language was limited to English. We additionally performed a manual search using the reference lists of key articles. Patients and study characteristics were extracted and the QUADAS-2 tool was employed to evaluate the quality of included studies. Sensitivity, specificity, the positive and negative likelihood ratio (PLR and NLR), diagnostic odds ratio (DOR), area under the curve (AUC), and 95% confidence interval (CI) were used to evaluate the diagnostic value of 18 F-PSMA PET/CT. Stata 17 software was employed for calculation and statistical analyses.

RESULTS

A total of eight diagnostic tests including 734 individual samples and 6346 lymph nodes were included in this meta-analysis. At the patient level, the results of each consolidated summary were as follows: sensitivity of 0.57 (95% CI 0.39-0.73), specificity of 0.95 (95% CI 0.92-0.97), PLR of 11.2 (95% CI 6.6-19.0), NLR of 0.46 (95% CI 0.31-0.68), DOR of 25 (95% CI 11-54), and AUC of 0.94 (95% CI 0.92-0.96). At the lesion level, the results of each consolidated summary were as follows: sensitivity of 0.40 (95% CI 0.21-0.62), specificity of 0.99 (95% CI 0.95-1.00), PLR of 40.0 (95% CI 9.1-176.3), NLR of 0.61 (95% CI 0.42-0.87), DOR of 66 (95% CI 14-311), and AUC of 0.86 (95% CI 0.83-0.89).

CONCLUSIONS

18 F-PSMA PET/CT showed moderate sensitivity but high specificity in lymph node staging of medium/high-risk PCa. The diagnostic efficacy was almost equivalent to that reported for 68 Ga-PSMA PET/CT.

REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO), No. CRD42023391101.

Evaluating the value of 18F-PSMA-1007 PET/CT in the detection and identification of prostate cancer using histopathology as the standard

BACKGROUND

Prostate-specific membrane antigen (PSMA) PET/CT is a highly regarded radionuclide imaging modality for prostate cancer (PCa). This study aimed to evaluate the diagnostic performance of 18F-PSMA-1007 PET/CT in detecting intraprostatic lesions of PCa using radical prostatectomy (RP) specimens as a reference standard and to establish an optimal maximum standardized uptake value (SUVmax) cutoff for distinguishing between PCa and non-PCa lesions.

METHODS

We retrospectively collected 117 patients who underwent 18F-PSMA-1007 PET/CT before RP. The uptake of the index tumor and contralateral non-PCa lesion was assessed. Histopathology of RP specimens was used as the gold standard. Kappa test was used to evaluate the consistency of preoperative PSMA PET/CT staging and postoperative pathological staging. Finally, an SUVmax cutoff value was identified by receiver operating characteristic (ROC) curve analysis to distinguish PCa lesions from non-PCa lesions. A prospective cohort including 76 patients was used to validate the results.

RESULTS

The detection rate of 18F-PSMA-1007 PET/CT for prostate cancer was 96.6% (113/117). 18F-PSMA-1007 had a sensitivity of 91.2% and a positive predictive value (PPV) of 89.8% for the identification of intraprostatic lesions. The consistency test (Kappa = 0.305) indicated poor agreement between the pathologic T-stage and PSMA PET/CT T-stage. Based on ROC curve analysis, the appropriate SUVmax to diagnose PCa lesions was 8.3 (sensitivity of 71.3% and specificity 96.8%) with an area under the curve (AUC) of 0.93 (P < 0.001). This SUVmax cutoff discriminated PCa lesions from non-PCa lesions with a sensitivity of 74.4%, a specificity of 95.8% in the prospective validation group.

CONCLUSIONS

18F-PSMA-1007 PET/CT demonstrated excellent performance in detecting PCa. An optimal SUVmax threshold (8.3) could be utilized to identify lesions of PCa by 18F-PSMA-1007 PET/CT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04521894, Registered: August 17, 2020.

An exploratory study of unexplained concentration of 18F-PSMA-1007 in the bladder for prostate cancer PET/CT imaging

18F-PSMA-1007 PET/CT imaging is increasingly used for the diagnosis, staging, and efficacy assessment of patients with prostate cancer. Compared with other PSMA tracers, 18F-PSMA-1007 is mainly cleared by the liver and bile and has lower urinary clearance, thus allowing a better assessment of the lesions around the bladder. However, there were some patients who showed an obvious concentration of the 18F-PSMA-1007 in the bladder, which may affect the observation of peripheral lesions, but the mechanism of this change is unknown. The aim of this study was to explore the cause of bladder 18F-PSMA-1007 concentration by assessing the clinical and imaging characteristics of 18F-PSMA-1007 PET/CT scans. A total of 284 patients were included in this retrospective study, and their clinical characteristics such as age, height, weight, Gleason score, metastases, different treatment methods, the level of liver and kidney function, PSA level, and imaging characteristics such as 18F-PSMA-1007 injected activity, the interval between injection to scan, physiological distribution (parotid gland, kidney, liver, spleen, intestine, obturator internus), pathological distribution (prostate lesions, metastases) were collected, and were compared after subgrouping using bladder urine SUVmax. This study showed that the distribution of bladder 18F-PSMA-1007 was not correlated with the above clinical and imaging characteristics, so further studies are needed to find the explanations, and thus to improve the disease assessment of this type of prostate cancer patients.

Advanced PSMA-PET/CT Imaging Parameters in Newly Diagnosed Prostate Cancer Patients for Predicting Metastatic Disease

(1) Purpose: Recent studies indicate that advanced imaging parameters such as prostate PSMA tumor volume may have a value in predicting response to treatment of castration-resistant prostate cancer patients. In this study, we examine whether a relationship can be found between advanced imaging parameters such as prostate PSMA-TV and the presence of metastatic disease in newly diagnosed prostate cancer patients undergoing PSMA-PET/CT for staging purposes; (2) Methods: We retrospectively analyzed PET/CT studies of 91 patients with newly diagnosed prostate cancer. Prostate PSMA-TV was measured using the MIRADA-XD software. PET/CT results were recorded, as well as additional clinical parameters such as the Gleason score, etc.; (3) Results: Prostate PSMA-TV measurements were found to be able to significantly differentiate metastatic from the non-metastatic patient groups (13.7 vs. 5.5, p-value < 0.05). Overall, 54% percent of patients with levels of over 8.1 PSMA-TV had metastatic lesions found on their PSMA-PET/CT. A model based on this cutoff attained a sensitivity of 80%, a specificity of 68.3%, and a negative predictive value of 93.5% for identifying metastatic disease. Another bin model was found statistically capable of assessing the likelihood of the presence of metastatic disease with a p-value of 0.001; (4) Conclusions: Prostate PSMA-TV measurement has the potential to predict the presence of metastatic disease at staging and thus may impact further treatment decision and patient management.

68Ga-PSMA-11 PET/MRI versus multiparametric MRI in men referred for prostate biopsy: primary tumour localization and interreader agreement

Background

Magnetic resonance imaging (MRI) is recommended by the European Urology Association guidelines as the standard modality for imaging-guided biopsy. Recently positron emission tomography with prostate-specific membrane antigen (PSMA PET) has shown promising results as a tool for this purpose. The aim of this study was to compare the accuracy of positron emission tomography with prostate-specific membrane antigen/magnetic resonance imaging (PET/MRI) using the gallium-labeled prostate-specific membrane antigen (⁶⁸Ga-PSMA-11) and multiparametric MRI (mpMRI) for pre-biopsy tumour localization and interreader agreement for visual and semiquantitative analysis. Semiquantitative parameters included apparent diffusion coefficient (ADC) and maximum lesion diameter for mpMRI and standardized uptake value (SUV_max) and PSMA-positive volume (PSMA_vol) for PSMA PET/MRI.

Results

Sensitivity and specificity were 61.4% and 92.9% for mpMRI and 66.7% and 92.9% for PSMA PET/MRI for reader one, respectively. RPE was available in 23 patients and 41 of 47 quadrants with discrepant findings. Based on RPE results, the specificity for both imaging modalities increased to 98% and 99%, and the sensitivity improved to 63.9% and 72.1% for mpMRI and PSMA PET/MRI, respectively. Both modalities yielded a substantial interreader agreement for primary tumour localization (mpMRI kappa = 0.65 (0.52–0.79), PSMA PET/MRI kappa = 0.73 (0.61–0.84)). ICC for SUV_max, PSMA_vol and lesion diameter were almost perfect (≥ 0.90) while for ADC it was only moderate (ICC = 0.54 (0.04–0.78)). ADC and lesion diameter did not correlate significantly with Gleason score (ρ = 0.26 and ρ = 0.16) while SUV_max and PSMA_vol did (ρ =  − 0.474 and ρ =  − 0.468).

Conclusions

PSMA PET/MRI has similar accuracy and reliability to mpMRI regarding primary prostate cancer (PCa) localization. In our cohort, semiquantitative parameters from PSMA PET/MRI correlated with tumour grade and were more reliable than the ones from mpMRI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41824-022-00135-4.

Stereotactic prostate radiotherapy with or without androgen deprivation therapy, study protocol for a phase III, multi-institutional randomized-controlled trial

Objective

The therapeutic landscape for localized prostate cancer (PC) is evolving. Stereotactic radiotherapy (SRT) has been reported to be at least not inferior to standard radiotherapy, but the effect of androgen deprivation therapy (ADT) in this setting is still unknown and its use is left to clinical judgment. There is therefore the need to clarify the role of ADT in association with SRT, which is the aim of the present study.

Methods

We present a study protocol for a randomized, multi-institutional, Phase III clinical trial, designed to study SRT in unfavorable intermediate and a subclass of high-risk localized PC. Patients (pts) will be randomized 1:1 to SRT + ADT or SRT alone. SRT will consists in 36.25 Gy in 5 fractions, ADT will be a single administration of Triptorelin 22.5 mg concurrent to SRT. Primary end point will be biochemical disease-free survival. Secondary end points will be disease-free survival, freedom from local recurrence, freedom from regional recurrence, freedom from distant metastasis and overall survival (OS); quality of life QoL and patient reported outcomes will be an exploratory end point and will be scored with EPIC-26, EORTC PR 25, IPSS, IIEF questionnaires in SRT + ADT and SRT alone arms. Moreover, clinician reported acute and late toxicity, assessed with CTCAE v. 5.0 scales will be safety end points.

Results

Sample size is estimated of 310 pts. For acute toxicity and quality of life results are awaited after 6 months since last patient in, whereas, for efficacy end points and late toxicity mature results will be available 3-5 years after last patient in.

Conclusion

Evidence is insufficient to guide decision making concerning ADT administration in the new scenario of prostate ultra-hypofractionation. Hence, the need to investigate the ADT role in SRT specific setting.

Advances in knowledge

The stereotactic prostate radiotherapy with or without ADT trial (SPA Trial) has been designed to establish a new standard of care for SRT in localized unfavorable intermediate and a subclass of localized high risk PC.

Early results of PRO-EPI: PROspective multicenter observational study on elective pelvic nodes irradiation in patients with intermediate/high/very high-risk non-metastatic prostate cancer submitted to radical, adjuvant, or salvage radiotherapy with or without concomitant androgen deprivation therapy

Simple Summary: Although radiotherapy plays a fundamental role in the management of intermediate/high/very high-risk non-metastatic prostatic cancer (IHR-nmPca), there is still no consensus on the optimal treatment strategy in this setting. Remarkably, the role of elective nodal irradiation (ENI) is still highly controversial. The PROspective multicenter observational study on Elective Pelvic nodes Irradiation (PRO-EPI) was designed to provide "real life" data regarding the patterns of care for IHR-nmPca. Forty-three Italian Radiation Oncology centers participated in the PROspective multicenter observational study on Elective Pelvic nodes Irradiation (PRO-EPI) project, with 1029 patients enrolled. In this preliminary analysis, we longitudinally evaluated the impact of Elective Nodal Irradiation (ENI) and radiotherapy features on toxicity and quality of life (QoL). Six months follow-up data were available for 913 patients and 12 months data for 762 patients. Elective Nodal Irradiation was given to 506 patients (48.9%). Volumetric Intensity-Modulated Radiation Therapy (IMRT) was adopted in more than 77% of patients and Image-Guided Radiation Therapy (IGRT) in 84.4%. Androgen deprivation therapy (ADT) was administered to the majority of patients (68.3%), and it was associated to ENI in 408 cases (81.1%). Toxicity was mostly mild and reversible and IGRT resulted in a significant reduction of rectal toxicity, although a non-significant trend toward increased urinary toxicity was observed. No statistically significant differences in QoL and toxicity were seen in patients treated with or without ENI. The adoption of IGRT is widespread and increasing and could reduce treatment toxicity. ENI is not yet the standard treatment, but it is performed in a growing fraction of cases and not resulting into an increase in toxicity or in a deterioration of QoL. Further analyses are needed to clarify the long-term toxicity profile and the impact of ENI on survival.

Local Failure Events in Prostate Cancer Treated with Radiotherapy: A Pooled Analysis of 18 Randomized Trials from the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium (LEVIATHAN)

CONTEXT

The prognostic importance of local failure after definitive radiotherapy (RT) in National Comprehensive Cancer Network intermediate- and high-risk prostate cancer (PCa) patients remains unclear.

OBJECTIVE

To evaluate the prognostic impact of local failure and the kinetics of distant metastasis following RT.

EVIDENCE ACQUISITION

A pooled analysis was performed on individual patient data of 12 533 PCa (6288 high-risk and 6245 intermediate-risk) patients enrolled in 18 randomized trials (conducted between 1985 and 2015) within the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium. Multivariable Cox proportional hazard (PH) models were developed to evaluate the relationship between overall survival (OS), PCa-specific survival (PCSS), distant metastasis-free survival (DMFS), and local failure as a time-dependent covariate. Markov PH models were developed to evaluate the impact of specific transition states.

EVIDENCE SYNTHESIS

The median follow-up was 11 yr. There were 795 (13%) local failure events and 1288 (21%) distant metastases for high-risk patients and 449 (7.2%) and 451 (7.2%) for intermediate-risk patients, respectively. For both groups, 81% of distant metastases developed from a clinically relapse-free state (cRF state). Local failure was significantly associated with OS (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.06-1.30), PCSS (HR 2.02, 95% CI 1.75-2.33), and DMFS (HR 1.94, 95% CI 1.75-2.15, p < 0.01 for all) in high-risk patients. Local failure was also significantly associated with DMFS (HR 1.57, 95% CI 1.36-1.81) but not with OS in intermediate-risk patients. Patients without local failure had a significantly lower HR of transitioning to a PCa-specific death state than those who had local failure (HR 0.32, 95% CI 0.21-0.50, p < 0.001). At later time points, more distant metastases emerged after a local failure event for both groups.

CONCLUSIONS

Local failure is an independent prognosticator of OS, PCSS, and DMFS in high-risk and of DMFS in intermediate-risk PCa. Distant metastasis predominantly developed from the cRF state, underscoring the importance of addressing occult microscopic disease. However a "second wave" of distant metastases occurs subsequent to local failure events, and optimization of local control may reduce the risk of distant metastasis.

PATIENT SUMMARY

Among men receiving definitive radiation therapy for high- and intermediate-risk prostate cancer, about 10% experience local recurrence, and they are at significantly increased risks of further disease progression. About 80% of patients who develop distant metastasis do not have a detectable local recurrence preceding it.

Prostate specific membrane antigen positron emission tomography in primary prostate cancer diagnosis: First-line imaging is afoot

Prostate specific membrane antigen positron emission tomography (PSMA PET) is an excellent molecular imaging technique for prostate cancer. Currently, PSMA PET for patients with primary prostate cancer is supplementary to conventional imaging techniques, according to guidelines. This supplementary function of PSMA PET is due to a lack of systematic review of its strengths, limitations, and potential development direction. Thus, we review PSMA ligands, detection, T, N, and M staging, treatment management, and false results of PSMA PET in clinical studies. We also discuss the strengths and challenges of PSMA PET. PSMA PET can greatly increase the detection rate of prostate cancer and accuracy of T/N/M staging, which facilitates more appropriate treatment for primary prostate cancer. Lastly, we propose that PSMA PET could become the first-line imaging modality for primary prostate cancer, and we describe its potential expanded application.

Predictors of Bone Metastases at 68Ga-PSMA-11 PET/CT in Hormone-Sensitive Prostate Cancer (HSPC) Patients with Early Biochemical Recurrence or Persistence

Prostate-specific-membrane-antigen/positron-emission-tomography (PSMA-PET) can accurately detect disease localizations in prostate cancer (PCa) patients with early biochemical recurrence/persistence (BCR/BCP), allowing for more personalized image-guided treatments in oligometastatic patients with major impact in the case of bone metastases (BM). Therefore, this study aimed to identify predictors of BM at PSMA-PET in early-BCR/BCP hormone-sensitive PCa (HSPC) patients, previously treated with radical intent (radiotherapy or radical prostatectomy ± salvage-radiotherapy (SRT)). A retrospective analysis was performed on 443 ⁶⁸Ga-PSMA-11-PET/CT scans. The cohort median PSA at PET-scan was 0.60 (IQR: 0.38–1.04) ng/mL. PSMA-PET detection rate was 42.0% (186/443), and distant lesions (M1a/b/c) were found in 17.6% (78/443) of cases. BM (M1b) were present in 9.9% (44/443) of cases, with 70.5% (31/44) showing oligometastatic spread (≤3 PSMA-positive lesions). In the multivariate binary logistic regression model (accuracy: 71.2%, Nagelkerke-R²: 13%), T stage ≥ 3a (OR: 2.52; 95% CI: 1.13–5.60; p = 0.024), clinical setting (previous SRT vs. first-time BCR OR: 2.90; 95% CI: 1.32–6.35; p = 0.008), and PSAdt (OR: 0.93; 95% CI: 0.88–0.99; p = 0.026) were proven to be significant predictors of bone metastases, with a 7% risk increment for each single-unit decrement of PSAdt. These predictors could be used to further refine the indication for PSMA-PET in early BCR/BCP HSPC patients, leading to higher detection rates of bone disease and more personalized treatments.

PSMA PET in Imaging Prostate Cancer

After prostate malignancy diagnosis, precise determination of disease extent are fundamental steps for tailored made therapy. The earlier the diagnosis of the burden of the disease, the longer the survival in many cases. National and international guidelines are based on “classic” imaging technics combining radiological and nuclear medicine scans like CT, MRI and bone scintigraphy (BS). The most recent nuclear medicine development is the prostate specific membrane antigen (PSMA) PET and is emerging as the most promising tool of medical imaging, gaining ground every day. Nevertheless, the different onset among multiple studies fails to establish a worldwide admission and incorporation of this technique in guidelines and its position in workaday medical algorithms. It seems that the medical community agrees not to utilize PSMA PET for low-risk patients; intense debate and research is ongoing for its utility in intermediate risk patients. Contrariwise, in high-risk patients PSMA PET is confirmed outperforming CT and BS combined. Additionally, irrespectively to their castration status, patients with biochemical failure should be referred for PSMA PET. Even though PSMA PET reveals more extended disease than expected or exonerates equivalent lesions, thus impacting treatment optimization. Studies being in progress and future trials with clarify whether PSMA PET will be the new gold standard technic for specific groups of patients.

Efficacy of 68Ga-PSMA-11 PET/CT with biparametric MRI in diagnosing prostate cancer and predicting risk stratification: a comparative study

BACKGROUND

This retrospective study aimed to investigate the efficacy of the combined application of biparametric magnetic resonance imaging (bpMRI) and ⁶⁸Ga-PSMA-11 positron emission computed tomography/computed tomography (bpMRI/PET) in the qualitative diagnosis of intermediate- to high-risk prostate cancer (PCa).

METHODS

The 105 patients with suspected PCa included in the study underwent bpMRI and PET/CT. BpMRI examinations included conventional sequences and diffusion-weighted imaging (DWI) sequences. Major lesions were qualitatively diagnosed according to the Prostate Imaging Reporting and Data System (PI-RADS). A PET/CT scan was started 60 min after intravenous ⁶⁸Ga-PSMA-11 injection. The area with the highest radioactivity on PET/CT images was defined as the major lesion, and the maximum standard uptake value (SUV_max) was measured. All cases were confirmed by biopsy and pathology. Receiver operating characteristic curve (ROC) analysis was performed on the data to calculate sensitivity, specificity, and the Youden index.

RESULTS

Of the 105 patients, 68 patients were diagnosed with PCa, and 37 patients had benign prostatic lesions. With a PI-RADS score ≥3 as the diagnostic threshold, the accuracy of bpMRI in identifying benign and malignant prostate lesions was similar to that of PET/CT (SUV_max threshold ≥10.9), and the Youden indices were 0.60 and 0.64, respectively. The sensitivity and specificity of bpMRI in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 63% and 88%, respectively, and the Youden index was 0.51. With an SUV_max ≥12.9 as the diagnostic threshold, the sensitivity and specificity of PET/CT in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 74% and 94%, respectively, and the Youden index was 0.68. The sensitivity and specificity of bpMRI/PET in diagnosing PCa were 94% and 81%, respectively, and the Youden index was 0.75. The sensitivity and specificity of bpMRI/PET in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 80% and 88%, respectively, and the Youden index was 0.68.

CONCLUSIONS

The combined application of bpMRI and PET improves the accuracy of the qualitative diagnosis of prostate lesions, and its diagnostic efficacy for risk stratification in patients with intermediate- to high-risk PCa is similar to that of PET/CT and higher than that of bpMRI alone.

Is there a nonnegligible effect of maximum standardized uptake value in the staging and management of prostate cancer with 68Ga-prostate-specific membrane antigen positron emission tomography/computerized tomography imaging? A single-center experience

Purpose

Prostate-specific membrane antigen (PSMA) positron emission tomography/computerized tomography (PET/CT) has been shown to have significant success in detecting local and distant metastases that cannot not be detected by conventional imaging. Initial staging in intermediate- and high-risk patients with prostate cancer is important for management. In addition, PSMA uptake has been shown to have a relation with grade of disease, and thus could be considered a separate noninvasive prognostic factor. In this study, we aimed to investigate the effect of PSMA PET/CT in the staging and management of prostate cancer patients as well as the relation to maximum standardized uptake value (SUVmax).

Methods

The patients referred to our department for staging prostate cancer were evaluated retrospectively (n = 65). Patients were grouped as positive for lymph node or distant metastatic disease. Primary tumor SUVmax data were compared with the prognostic factors of the disease. In addition, decisions about treatment protocol before and after PSMA PET/CT imaging were noted.

Results

All the patients except one were accepted as positive for primary tumor. Of the patients, 46.2% were positive for lymph node and 24.6% for distant metastases. After evaluation by PSMA PET/CT, the clinical choice of treatment changed for 43.1% of our patients. Primary tumor SUVmax and tumor-to-background SUVmax ratios were found to have a significant relation with D'Amico risk classification. We found a positive correlation between SUVmax and prostate-specific antigen, Gleason scores, and age.

Conclusion

PSMA PET/CT images have a nonnegligible effect on staging, clinical decisions, and change in treatment protocol. SUVmax data have a positive correlation with risk classification and could be identified as a potential independent and non-invasive prognostic factor.

Preparation of 177Lu-PSMA-617 in Hospital Radiopharmacy: Convenient Formulation of a Clinical Dose Using a Single-Vial Freeze-Dried PSMA-617 Kit Developed In-House

Objective

In the recent time, endoradionuclide therapy for metastatic castration-resistant prostate carcinoma employing ¹⁷⁷Lu-PSMA-617 has yielded encouraging results and several clinical trials with the agent are currently ongoing. Routine preparation of ¹⁷⁷Lu-PSMA-617 patient doses can be made simpler and convenient, if the ingredients essential for radiolabeling are made available in a ready-to-use lyophilized form.

Methods

PSMA-617 freeze-dried kit was formulated and used for the preparation of ¹⁷⁷Lu-PSMA-617 clinical dose with high radiochemical purity using low/medium specific activity ¹⁷⁷Lu. Detailed radiochemical studies were performed to determine the maximum activity and volume of ¹⁷⁷LuCl₃, which can be added in the kit for the formulation of ¹⁷⁷Lu-PSMA-617. Studies were also performed to determine the shelf life of the kit to ensure its long-term usage. Studies were performed in buffer as well as human serum medium to determine the stability of the ¹⁷⁷Lu-PSMA-617 complex after storing in respective media up to 7 days postpreparation. About ten patient doses of ¹⁷⁷Lu-PSMA-617 were administered, and posttherapy scans were acquired.

Results

The formulated freeze-dried kit of PSMA-617 could be radiolabeled with an average percentage radiochemical purity > 98.53 ± 0.38. The freeze-dried kit was found suitable for tolerating up to 0.5 mL of ¹⁷⁷LuCl₃ (in 0.01 N HCl) and specific activity of 555 MBq/μg (15 mCi/μg) for the preparation of the patient dose of ¹⁷⁷Lu-PSMA-617. The ¹⁷⁷Lu-PSMA-617 complex prepared using the freeze-dried kit of PSMA-617 was observed to maintain % radiochemical purity (RCP) of 96.74 ± 0.87 and 94.81 ± 2.66, respectively, even after storing up to 7 days in buffer and human serum, respectively. ¹⁷⁷Lu-PSMA-617 prepared using the in-house formulated freeze-dried kit of PSMA-617 exhibited accumulation in metastatic lesions picked up in a pretherapy PET scan. Reduction in number as well as size of lesions was observed in posttherapy scans acquired after two months of administering the first therapeutic dose of ¹⁷⁷Lu-PSMA-617.

Conclusions

The freeze-dried kit of PSMA-617 could be used for the preparation of ¹⁷⁷Lu-PSMA-617 with high radiochemical purity (>98%) in a reproducible manner. ¹⁷⁷Lu-PSMA-617 prepared using the developed kit was successfully evaluated in patients suffering from metastatic prostate cancer.

Primary staging in patients with intermediate- and high-risk prostate cancer: Multiparametric MRI and 68Ga-PSMA-PET/MRI - What is the value of quantitative data from multiparametric MRI alone or in conjunction with clinical information?

PURPOSE

Comparing mpMRI and ⁶⁸Ga-PSMA-PET/MRI in primary staging of PCa and investigating the value of quantitative mpMRI-measurements for prediction of extracapsular extension and N-metastases.

METHODS

Patients with PCa undergoing ⁶⁸Ga-PSMA-PET/MRI and mpMRI during January 2016 to February 2019 were retrospectively included. Two readers each on ⁶⁸Ga-PSMA-PET/MRI or mpMRI rated extraprostatic extension (≥T3) and regional lymph-node-metastasis (N1) on a Likert-scale. A fifth reader measured tumor volume, maximum diameter, and capsular contact length on mpMRI. Probability of lymph-node-metastasis was additionally calculated using the 2018 Briganti model. Interobserver-agreement was assessed by squared Cohen's kappa, and diagnostic accuracy was determined using radical prostatectomy (n = 35/49) as reference standard.

RESULTS

49 patients (median age 66 years [IQR: 61-72 years]) were evaluated. Interobserver-agreement for mpMRI and ⁶⁸Ga-PSMA-PET/MRI was: ≥T3: κ = 0.58/0.47; N1: κ = 0.55/0.92. Diagnostic accuracy for mpMRI vs ⁶⁸Ga-PSMA-PET/MRI readers for ≥ T3 was AUC: 0.72, 0.62 vs 0.71, 0.72 (p > 0.38) and for N1 was AUC: 0.39, 0.55 vs 0.72, 0.78 (p < 0.01). Quantitative parameters delivered diagnostic accuracies of: AUC: 0.70-0.72 for ≥ T3. The 2018 Briganti model achieved an AUC of 0.89 for N1.

CONCLUSIONS

Interreader-agreement regarding ≥ T3 was similar for mpMRI and ⁶⁸Ga-PSMA-PET/MRI while for N1 it was higher for ⁶⁸Ga-PSMA-PET/MRI. Diagnostic accuracy was comparable for ≥ T3 while for N1 it was higher in ⁶⁸Ga-PSMA-PET/MRI and the 2018 Briganti model. Combining clinical data and quantitative data from mpMRI in the 2018 Briganti model yielded the highest AUC for prediction of lymph node metastasis and may aid in selecting patients who will benefit from ⁶⁸Ga-PSMA-PET/MRI for primary staging.

Dose-escalated pelvic radiotherapy for prostate cancer in definitive or postoperative setting

PURPOSE

Given the absence of standardized planning approach for clinically node-positive (cN1) prostate cancer (PCa), we collected data about the use of prophylactic pelvic irradiation and nodal boost. The aim of the present series is to retrospectively assess clinical outcomes after this approach to compare different multimodal treatment strategies in this scenario.

METHODS

Data from clinical records of patients affected by cN1 PCa and treated in six different Italian institutes with prophylactic pelvic irradiation and boost on pathologic pelvic lymph nodes detected with CT, MRI or choline PET/CT were retrospectively reviewed and collected. Clinical outcomes in terms of overall survival (OS) and biochemical relapse-free survival (b-RFS) were explored. The correlation between outcomes and baseline features (International Society of Urological Pathology-ISUP pattern, total dose to positive pelvic nodes ≤ / > 60 Gy, sequential or simultaneous integrated boost (SIB) administration and definitive vs postoperative treatment) was explored.

RESULTS

ISUP pattern < 2 was a significant predictor of improved b-RFS (HR = 0.3, 95% CI 0.1220-0.7647, P = 0.0113), while total dose < 60 Gy to positive pelvic nodes was associated with worse b-RFS (HR = 3.59, 95% CI 1.3245-9.741, P = 0.01). Conversely, treatment setting (postoperative vs definitive) and treatment delivery technique (SIB vs sequential boost) were not associated with significant differences in terms of b-RFS (HR = 0.85, 95% CI 0.338-2.169, P = 0.743, and HR = 2.39, 95% CI 0.93-6.111, P = 0.067, respectively).

CONCLUSION

Results from the current analysis are in keeping with data from literature showing that pelvic irradiation and boost on positive nodes are effective approaches. Upfront surgical approach was not associated with better clinical outcomes.

Expression of neurotensin receptor-1 (NTS1) in primary breast tumors, cellular distribution, and association with clinical and biological factors

PURPOSE

Neurotensin receptor-1 (NTS₁) is increasingly recognized as a potential target in diverse tumors including breast cancer, but factors associated with NTS₁ expression have not been fully clarified.

METHODS

We studied NTS₁ expression using the Tissue MicroArray (TMA) of primary breast tumors from Institut Bergonié. We also studied association between NTS₁ expression and clinical, pathological, and biological parameters, as well as patient outcomes.

RESULTS

Out of 1419 primary breast tumors, moderate to strong positivity for NTS₁ (≥ 10% of tumoral cells stained) was seen in 459 samples (32.4%). NTS₁ staining was cytoplasmic in 304 tumors and nuclear in 155 tumors, a distribution which appeared mutually exclusive. Cytoplasmic overexpression of NTS₁ was present in 21.5% of all breast tumors. In multivariate analysis, factors associated with cytoplasmic overexpression of NTS₁ in breast cancer samples were higher tumor grade, Ki67 ≥ 20%, and higher pT stage. Cytoplasmic NTS₁ was more frequent in tumors other than luminal A (30% versus 17.3%; p < 0.0001). Contrastingly, the main "correlates" of a nuclear location of NTS₁ were estrogen receptor (ER) positivity, low E&E (Elston and Ellis) grade, Ki67 < 20%, and lower pT stage. In NTS₁-positive samples, cytoplasmic expression of NTS₁ was associated with shorter 10-year metastasis-free interval (p = 0.033) compared to NTS₁ nuclear staining. Ancillary analysis showed NTS₁ expression in 73% of invaded lymph nodes from NTS₁-positive primaries.

CONCLUSION

NTS₁ overexpression was found in about one-third of breast tumors from patients undergoing primary surgery with two distinct patterns of distribution, cytoplasmic distribution being more frequent in aggressive subtypes. These findings encourage the development of NTS₁-targeting strategy, including radiopharmaceuticals for imaging and therapy.

Clinical evaluation of data-driven respiratory gating for PET/CT in an oncological cohort of 149 patients: impact on image quality and patient management

OBJECTIVES

To evaluate the impact of fully automatic motion correction by data-driven respiratory gating (DDG) on positron emission tomography (PET) image quality, lesion detection and patient management.

MATERIALS AND METHODS

A total of 149 patients undergoing PET/CT for cancer (re-)staging were retrospectively included. Patients underwent a PET/CT on a digital detector scanner and for every patient a PET data set where DDG was enabled (PET_DDG) and as well as where DDG was not enabled (PET_nonDDG) was reconstructed. All PET data sets were evaluated by two readers which rated the general image quality, motion effects and organ contours. Further, both readers reviewed all scans on a case-by-case basis and evaluated the impact of PET_DDG on additional apparent lesion, change of report, and change of management.

RESULTS

In 85% (n = 126) of the patients, at least one bed position was acquired using DDG, resulting in mean scan time increase of 4:37 min per patient in the whole study cohort (n = 149). General image quality was not rated differently for PET_nonDDG and PET_DDG images (p = 1.000) while motion effects (i.e. indicating general blurring) was rated significantly lower in PET_DDG images and organ contours, including liver and spleen, were rated significantly sharper using PET_DDG as compared to PET_nonDDG (all p < 0.001). In 27% of patients, PET_DDG resulted in a change of the report and in a total of 12 cases (8%), PET_DDG resulted in a change of further clinical management.

CONCLUSION

Deviceless DDG provided reliable fully automatic motion correction in clinical routine and increased lesion detectability and changed management in a considerable number of patients.

ADVANCES IN KNOWLEDGE

DDG enables PET/CT with respiratory gating to be used routinely in clinical practice without external gating equipment needed.

How accurate is 68Gallium-prostate specific membrane antigen positron emission tomography / computed tomography (68Ga-PSMA PET/CT) on primary lymph node staging before radical prostatectomy in intermediate and high risk prostate cancer? A study of patient- and lymph node- based analyses

BACKGROUND AND AIM

Gallium-68 (68Ga)-Prostate Membrane Specific Antigen Positron Emission Tomography/Computed Tomography (68Ga-PSMA PET/CT) is an emerging diagnostic modality which is gaining importance in individualized prostate cancer (PCa) management era. This study aimed to investigate the diagnostic accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging before radical prostatectomy (RP) in intermediate and high risk PCa.

MATERIALS AND METHODS

The retrospectively documented 49 patients with intermediate and high risk non-metastatic PCa who had ⁶⁸Ga-PSMA PET/CT before RP were enrolled into this study. The histopathology of dissected LNs was used as reference standard to evaluate the accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging, both in per-patient (n = 49) and in per-node (n = 454) analyses. The diagnostic accuracy was investigated using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and by area under the curve (AUC) provided using receiver operating curve (ROC) analysis.

RESULTS

Median age was 64 (48-79) years and, median and mean PSA values were 10 (1.31-138) ng/ml and 16.2 (±19.8) ng/ml, respectively. 22 (44.9%) and 27 (55.1%) of patients had intermediate and high risk PCa, respectively. A total of 5 (10.2%) patients had histopathologically proven LN metastasis and 3 (60%) of them was detected in ⁶⁸Ga-PSMA PET/CT. In per patient analysis, the sensitivity, specifity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.60, 0.96, 0.60 and 0.96, respectively. Among overall 454 LNs, 16 (3.5 %) of them were reported as metastatic in histopathology and, 13 (2.9%) of these metastatic LNs were detected in ⁶⁸Ga-PSMA PET/CT. In per-node analysis, the sensitivity, specificity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.82, 0.99, 0.87 and 0.99, respectively. The ROC analyses found AUCs for primary LN staging as 0.777 (95%CI:0.508-1.0) in per patient analysis and, as 0.904 (95%CI:0.790 - 1.0) in per node analysis, respectively.

CONCLUSION

The use of ⁶⁸Ga-PSMA PET/CT has promising diagnostic accuracy on primary LN staging before RP in intermediate and high risk PCa. However, the efforts should be taken to increase sensitivity of ⁶⁸Ga-PSMA PET/CT in individualized treatment era.

[Positron emission tomography with computed tomography/magnetic resonance imaging for primary staging of prostate cancer]

CLINICAL/METHODOLOGICAL ISSUE

Prostate cancer is the most common malignancy and the second leading cause of cancer-related death in men. Accurate imaging diagnosis and staging are crucial for patient management and treatment. The role of nuclear medicine in the diagnosis of prostate cancer has evolved rapidly in recent years due to the availability of hybrid imaging with radiopharmaceuticals targeting the prostate-specific membrane antigen (PSMA).

STANDARD RADIOLOGICAL PROCEDURES

Hybrid imaging provides higher diagnostic accuracy compared to conventional imaging and has a significant impact on clinical management. Numerous radiotracers have been used in clinical applications, with PSMA ligands being the most commonly used.

METHODOLOGICAL INNOVATIONS

Hybrid imaging provides higher diagnostic accuracy for lymph node and bone metastases compared to conventional imaging and has a significant impact on clinical management.

PERFORMANCE

The high accuracy for primary staging in high-risk prostate cancer using PSMA ligands has led to the inclusion of PSMA positron emission tomography (PET)/computed tomography (CT) in the new German S3 guideline for primary staging of prostate cancer.

PURPOSE

The aim of this article is to provide an overview of the use of PET imaging in the primary diagnosis of prostate cancer, to present the most commonly used radiotracers, and to highlight the results of recent studies.

Focal unspecific bone uptake on [18F]-PSMA-1007 PET: a multicenter retrospective evaluation of the distribution, frequency, and quantitative parameters of a potential pitfall in prostate cancer imaging

Purpose

Improved logistics and availability led to a rapid increase in the use of [¹⁸F]-PSMA-1007 for prostate cancer PET imaging. Initial data suggests increased uptake in benign lesions compared to [⁶⁸ Ga]-PSMA-11, and clinical observations found increased unspecific bone uptake (UBU). We therefore investigate the frequency and characteristics of UBU in [¹⁸F]-PSMA-1007 PET.

Methods

We retrospectively analyzed [¹⁸F]-PSMA-1007 PET scans from four centers for the presence of UBU, defined as a focal mild-to-moderate uptake (SUV_max < 10.0) not obviously related to a benign or malignant cause. If present, up to three leading UBUs were quantified (SUV_max), localized, and correlated to clinical parameters, such as age, PSA, injected dose, Gleason score, tumor size (T1–T4), and type of PET scanner (analog vs. digital). Additionally, clinical and imaging follow-up results and therapeutic impact were evaluated.

Results

UBUs were identified in 179 out of 348 patients (51.4%). The most frequent localizations were ribs (57.5%) and pelvis (24.8%). The frequency of UBUs was not associated with PSA, Gleason score, tumor size, age, or the injected [¹⁸F]-PSMA-1007 dose. UBUs were significantly more frequent in images obtained with digital PET/CT scans (n = 74, 82%) than analog PET/CT scans (n = 221, 40.3%) (p = .0001) but not in digital PET/MR (n = 53, 51%) (p = .1599). In 80 out of 179 patients (44.7%), the interpretation of UBUs was critical for therapeutic management and therefore considered clinically relevant. For 65 UBUs, follow-ups were available: three biopsies, three radiotherapies with PSA follow-up, and 59 cases with imaging. After follow-up, UBUs were still considered unclear in 28 of 65 patients (43%), benign in 28 (43%), and malignant in nine (14%) patients.

Conclusion

UBUs occur in two-thirds of patients imaged with [¹⁸F]-PSMA-1007 PET/CT and are significantly more frequent on digital PET scanners than analog scanners. UBUs should be interpreted carefully to avoid over-staging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05424-x.

The Establishment of New Thresholds for PLND-Validated Clinical Nomograms to Predict Non-Regional Lymph Node Metastases: Using 68Ga-PSMA PET/CT as References

Purpose

PLND (pelvic lymph node dissection)-validated nomograms are widely accepted clinical tools to determine the necessity of PLND by predicting the metastasis of lymph nodes (LNMs) in pelvic region. However, these nomograms are in lacking of a threshold to predict the metastasis of extrareolar lymph nodes beyond pelvic region, which is not suitable for PLND. The aim of this study is to evaluate a threshold can be set for current clinical PLND-validated nomograms to predict extrareolar LN metastases beyond pelvic region in high-risk prostate cancer patients, by using ⁶⁸Ga-PSMA PET/CT as a reference to determine LN metastases (LNMs).

Experimental Design

We performed a retrospective analysis of 57 high-risk treatment-naïve PC patients in a large tertiary care hospital in China who underwent ⁶⁸Ga-PSMA-617 PET/CT imaging. LNMs was detected by ⁶⁸Ga-PSMA-617 PET/CT and further determined by imaging follow-up after anti-androgen therapy. The pattern of LN metastatic spread of PC patients were evaluated and analyzed. The impact of ⁶⁸Ga-PSMA PET/CT on clinical decisions based on three clinical PLND-validated nomograms (Briganti, Memorial Sloan Kettering Cancer Center, Winter) were evaluated by a multidisciplinary prostate cancer therapy team. The diagnostic performance and the threshold of these nomograms in predicting extrareolar LNMs metastasis were evaluated via receiver operating characteristic (ROC) curve analysis.

Results

LNMs were observed in 49.1% of the patients by ⁶⁸Ga-PSMA PET/CT, among which 65.5% of LNMs were pelvic-regional and 34.5% of LNMs were observed in extrareolar sites (52.1% of these were located above the diaphragm). The Briganti, MSKCC and Winter nomograms showed that 70.2%-71.9% of the patients in this study need to receive ePLND according to the EAU and NCCN guidelines. The LN staging information obtained from ⁶⁸Ga-PSMA PET/CT would have led to changes of planned management in 70.2% of these patients, including therapy modality changes in 21.1% of the patients, which were mainly due to newly detected non-regional LNMs. The thresholds of nomograms to predict non-regional LNMs were between 64% and 75%. The PC patients with a score >64% in Briganti nomogram, a score >75% in MSKCC nomogram and a score >67% in Winter nomogram were more likely to have non-regional LNMs. The AUCs (Area under curves) of the clinical nomograms (Briganti, MSKCC and Winter) in predicting non-regional LNMs were 0.816, 0.830 and 0.793, respectively.

Conclusions

By using ⁶⁸Ga-PSMA PET/CT as reference of LNM, the PLND-validated clinical nomograms can not only predict regional LNMs, but also predict non-regional LNMs. The additional information from ⁶⁸Ga-PSMA PET/CT may provide added benefit to nomograms-based clinical decision-making in more than two-thirds of patients for reducing unnecessary PLND. We focused on that a threshold can be set for current clinical PLND-validated nomograms to predict extrareolar LN metastases with an AUC accuracy of about 80% after optimizing the simple nomograms which may help to improve the efficiency for PC therapy significantly in clinical practice.

Improved oncological outcome after radical prostatectomy in patients staged with 68Ga-PSMA-11 PET: a single-center retrospective cohort comparison

BACKGROUND

Positron emission tomography (PET) targeting the prostate-specific membrane antigen (PSMA) has superior sensitivity over conventional imaging (CI) to stage prostate cancer (PCa) and therefore is increasingly used in staging to stratify patients before radical therapy. Whether this improved diagnostic accuracy translates into improved outcome after radical prostatectomy (RPE) has not yet been shown. Therefore, the aim of this study was to compare the oncological outcome after RPE between patients that underwent preoperative staging with CI or PSMA-PET for intermediate and high-risk PCa.

METHODS

We retrospectively selected all patients that underwent RPE for intermediate- or high-risk PCa at our institution before PSMA-PET introduction (between March 2014 and September 2016) and compared the oncologic outcome of patients staged with PSMA-PET (between October 2016 and October 2018). Oncological pre-surgical risk parameters (age, PSA, D'Amico score, biopsy-ISUP, and cT stage) were compared between the groups. Oncological outcome was determined as PSA persistence, nerve-sparing rate, and surgical margin status. Wilcoxon rank-sum, Fisher's, and chi-square tests where used for statistical testing.

RESULTS

One hundred five patients were included, 53 in the CI group and 52 in the PSMA-group. Patients in the PSMA group had higher ISUP grade (p < 0.001) and D'Amico score (p < 0.05). The rate of free surgical margins and PSA persistence after RPE was 64% and 17% for the CI and 77% and 6% for the PSMA group (p = 0.15 and 0.13, respectively). Subgroup analysis with high-risk patients revealed PSA persistence in 7% (3/44) in the PSMA group and 25% (7/28) in the CI group (p = 0.04). Limitations include the retrospective design and choline-PET for some patients in the CI group.

CONCLUSION

Immediate outcome after RPE was not worse in the PSMA group compared with the CI group, despite a higher-risk cohort. In a comparison of only high-risk patients, PSMA-PET staging was associated with a significantly lower rate of postsurgical PSA persistence.

The role of 68Gallium-prostate-specific membrane antigen positron emission tomography on staging of high-risk localized prostate cancer: for all high-risk patients or would it be better to select them?

Background

According to pathologico-clinical features, patients diagnosed with localized prostate cancer (PCa) are stratified into distinct risk groups (low-risk, intermediate-risk or high-risk). Data have demonstrated that ⁶⁸Gallium-prostate-specific membrane antigen positron emission tomography (⁶⁸Ga-PSMA PET/CT) is superior to conventional radiological exams (CT or MRI and bone scintigraphy) in the primary staging of high-risk localized PCa. However, it is still unknown if in a population of high-risk PCa, there would be a subgroup of patients with a higher probability of identifying metastatic disease by the ⁶⁸Ga-PSMA PET/CT.

Materials and Methods

Data from patients with localized PCa who underwent ⁶⁸GA-PSMA PET/CT for primary staging from four institutions were retrospectively collected. We selected patients with at least one D'Amico classification risk factor (International Society of Urological Pathology ≥ IV and/or prostate-specific antigen > 20 ng/ml). To detect an association between extent of disease and number of risk factors as well as International Society of Urological Pathology prostate cancer grade, contingency tables were used, and Fisher Exact Test was performed.

Results

Between 2016 and 2020, 60 patients underwent a ⁶⁸GA-PSMA PET/CT for primary staging of high-risk localized PCa. Regarding the number of risk factors, 37 patients (62%) had one risk factor, and 23 (38%) had two risk factors. In the subgroup of patients with metastatic disease (n = 22), those with two risk factors had higher incidence of metastatic disease, and it was statistically significant (p = 0.011).

Conclusion

This retrospective analysis demonstrated that ⁶⁸GA-PSMA PET/CT was able to identify advanced disease in more than one-third of patients with high-risk disease especially those with two adverse risk factors.

Fluorine-18 labelled prostate-specific membrane antigen (PSMA)-1007 positron-emission tomography-computed tomography: normal patterns, pearls, and pitfalls

Prostate-specific membrane antigen (PSMA)-based positron-emission tomography (PET)-computed tomography (CT) has shown great promise in prostate cancer imaging. This technique has demonstrated particular utility in the staging of high-risk primary cancer and in the localisation of recurrent disease. The use of fluorine-18 PSMA-1007 is advantageous, as it is excreted via the hepatobiliary system rather than urinary and the longer half-life of fluorine-18 compared to gallium tracers, allows for PSMA imaging in centres without a gallium generator. However, imaging with this tracer is not without flaws and areas of ambiguity remain. In this article, the biodistribution, clinical indications, and pearls of ¹⁸F-PSMA-1007 PET-CT in patients with prostate cancer will be discussed, as well as the potential pitfalls in the reporting of these studies.

(Radio)Theranostic Patient Management in Oncology Exemplified by Neuroendocrine Neoplasms, Prostate Cancer, and Breast Cancer

The role of nuclear medicine in the management of oncological patients has expanded during last two decades. The number of radiopharmaceuticals contributing to the realization of theranostics/radiotheranostics in the context of personalized medicine is increasing. This review is focused on the examples of targeted (radio)pharmaceuticals for the imaging and therapy of neuroendocrine neoplasms (NENs), prostate cancer, and breast cancer. These examples strongly demonstrate the tendency of nuclear medicine development towards personalized medicine.