Prediction of T staging in PI-RADS 4-5 prostate cancer by combination of multiparametric MRI and 68Ga-PSMA-11 PET/CT.

BACKGROUND: In this study, we explored the diagnostic performances of multiparametric magnetic resonance imaging (mpMRI), 68 Ga-PSMA-11 PET/CT and combination of 68 Ga-PSMA-11 PET/CT and mpMRI (mpMRI + PET/CT) for extracapsular extension (ECE). Based on the analyses above, we tested the feasibility of using mpMRI + PET/CT results to predict T staging in prostate cancer patients. METHODS: By enrolling 75 patients of prostate cancer with mpMRI and 68 Ga-PSMA-11 PET/CT before radical prostatectomy, we analyzed the detection performances of ECE in mpMRI, 68 Ga-PSMA-11 PET/CT and mpMRI + PET/CT on their lesion images matched with their pathological sample images layer by layer through receiver operating characteristics (ROC) analysis. By inputting the lesion data into Prostate Imaging Reporting and Data System (PI-RADS), we divided the lesions into different PI-RADS scores. The improvement of detecting ECE was analyzed by net reclassification improvement (NRI). The predictors for T staging were evaluated by using univariate and multivariable analysis. The Kappa test was used to evaluate the prediction ability. RESULTS: One hundred three regions of lesion were identified from 75 patients. 50 of 103 regions were positive for ECE. The ECE diagnosis AUC of mpMRI + PET/CT is higher than that of mpMRI alone (ΔAUC = 0.101; 95% CI, 0.0148 to 0.1860; p < 0.05, respectively). Compared to mpMRI, mpMRI + PET/CT has a significant improvement in detecting ECE in PI-RADS 4-5 (NRI 36.1%, p < 0.01). The diagnosis power of mpMRI + PET/CT was an independent predictor for T staging (p < 0.001) in logistic regression analysis. In patients with PI-RADS 4-5 lesions, 40 of 46 (87.0%) patients have correct T staging prediction from mpMRI + PET/CT (κ 0.70, p < 0.01). CONCLUSION: The prediction of T staging in PI-RADS 4-5 prostate cancer patients by mpMRI + PET/CT had a quite good performance.

The Association Between [68Ga]PSMA PET/CT Response and Biochemical Progression in Patients with High-Risk Prostate Cancer Receiving Neoadjuvant Therapy.

Our previous study found that the prostate-specific membrane antigen (PSMA) PET/CT response of primary prostate cancer (PCa) to neoadjuvant therapy can predict the pathologic response. This study was designed to investigate the association between [68Ga]PSMA PET/CT changes and biochemical progression-free survival (bPFS) in high-risk patients who underwent neoadjuvant therapy before radical prostatectomy (RP). Methods: Seventy-five patients with high-risk PCa in 2 phase II clinical trials who received neoadjuvant therapy before RP were included. The patients received androgen deprivation therapy plus docetaxel (n = 33) or androgen deprivation therapy plus abiraterone (n = 42) as neoadjuvant treatment. All patients had serial [68Ga]PSMA PET/CT scans before and after neoadjuvant therapy. Age, initial prostate-specific antigen level, nadir prostate-specific antigen level before RP, tumor grade at biopsy, treatment regimen, clinical T stage, PET imaging features, pathologic N stage, and pathologic response on final pathology were included for univariate and multivariate Cox regression analyses to identify independent predictors of bPFS. Results: With a median follow-up of 30 mo, 18 patients (24%) experienced biochemical progression. Multivariate Cox regression analyses revealed that only SUVmax derived from posttreatment [68Ga]PSMA PET/CT and pathologic response on final pathology were independent factors for the prediction of bPFS, with hazard ratios of 1.02 (95% CI, 1.00-1.04; P = 0.02) and 0.12 (95% CI, 0.02-0.98; P = 0.048), respectively. Kaplan-Meier analysis revealed that patients with a favorable [68Ga]PSMA PET/CT response (posttreatment SUVmax < 8.5) or a favorable pathologic response (pathologic complete response or minimal residual disease) had a significantly lower rate of 3-y biochemical progression. Conclusion: Our results indicated that [68Ga]PSMA PET/CT response was an independent risk factor for the prediction of bPFS in patients with high-risk PCa receiving neoadjuvant therapy and RP, suggesting [68Ga]PSMA PET/CT to be an ideal tool to monitor response to neoadjuvant therapy.

Ability of 68 Ga-PSMA PET/CT SUVmax to differentiate ISUP GG2 from GG3 in intermediate-risk prostate cancer: A single-center retrospective study of 147 patients.

OBJECTIVE: To evaluate the ability of 68 Ga-PSMA PET/CT maximum standard uptake value (SUVmax) to distinguish prostate cancer (PCa) International Society of Urological Pathology ISUP grade group (GG) 2 and GG3. METHODS: The PET/CT images and data of 147 patients were analyzed retrospectively, and the SUVmax of the index lesions were measured. The receiver operating characteristic curve was used to analyze the diagnostic value of PET/CT for PCa. The correlation between SUVmax and ISUP GG was analyzed. A logistic regression model was established with SUVmax and was validated to predict its value of diagnosing intermediate- and high-risk PCa (ihPCa). RESULTS: Of the 147 patients, 112 cases were PCa (76.2%), and 35 cases were benign lesions (23.8%). There was a significant difference between the benign and the malignant groups (p < 0.05). The median SUVmax of ihPCa was significantly higher than that of the benign and low-risk groups (p < 0.05). The median SUVmax of GG3 was significantly higher than that of the GG2 group (p < 0.05). There were no statistically significant SUVmax differences among GG3, GG4, and GG5 groups (p > 0.05). The specificity and the positive predictive value of 68 Ga-PSMA PET/CT in the diagnosis of PCa were 97% and 99% with cut-off SUVmax of 6.94, while the specificity and the positive predictive value of ihPCa were 95% and 96% with cut-off SUVmax of 10.12. CONCLUSION: 68 Ga-PSMA PET/CT can reliably distinguish GG2 from GG3 PCa.

Deep learning based on 68Ga-PSMA-11 PET/CT for predicting pathological upgrading in patients with prostate cancer.

Objectives: To explore the feasibility and importance of deep learning (DL) based on 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT in predicting pathological upgrading from biopsy to radical prostatectomy (RP) in patients with prostate cancer (PCa). Methods: In this retrospective study, all patients underwent 68Ga-PSMA-11 PET/CT, transrectal ultrasound (TRUS)-guided systematic biopsy, and RP for PCa sequentially between January 2017 and December 2022. Two DL models (three-dimensional [3D] ResNet-18 and 3D DenseNet-121) based on 68Ga-PSMA-11 PET and support vector machine (SVM) models integrating clinical data with DL signature were constructed. The model performance was evaluated using area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. Results: Of 109 patients, 87 (44 upgrading, 43 non-upgrading) were included in the training set and 22 (11 upgrading, 11 non-upgrading) in the test set. The combined SVM model, incorporating clinical features and signature of 3D ResNet-18 model, demonstrated satisfactory prediction in the test set with an AUC value of 0.628 (95% confidence interval [CI]: 0.365, 0.891) and accuracy of 0.727 (95% CI: 0.498, 0.893). Conclusion: A DL method based on 68Ga-PSMA-11 PET may have a role in predicting pathological upgrading from biopsy to RP in patients with PCa.

Detection of Bone Metastases by 68Ga-DOTA-SSAs and 18F-FDG PET/CT: A Two-Center Head-to-Head Study of Gastroenteropancreatic Neuroendocrine Neoplasms.

Purpose: This study aimed to assess the efficacy of dual-tracer [68Ga-DOTA-somatostatin receptor analogs (SSAs) and 18F-fluorodeoxyglucose (FDG)] positron emission tomography/computed tomography (PET/CT) imaging for detecting bone metastases (BMs) in patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Methods: We retrospectively enrolled 74 GEP-NEN patients with BMs from two centers, who underwent dual-tracer PET/CT from January 2014 to March 2021. We compared and analyzed effectiveness of the dual PET/CT imaging techniques on the BMs, based on 18F-FDG and 68Ga-DOTA-SSAs. Specifically, we analyzed the imaging results using χ 2 tests for classification variables, paired-sample tests for number of BMs, Wilcoxon's signed rank test for number of lesions, and the Kruskal-Wallis test for standard uptake value (SUV) ratio comparison. The correlation of dual-tracer SUVmax with Ki-67 index was analyzed by Spearman's correlation coefficient. Results: The detection efficiencies of dual-tracer PET/CT imaging in patients with different pathologies showed discordant for detecting liver metastases and BMs in group neuroendocrine tumor (NET) G3, 68Ga-DOTA-SSAs was better at detecting BMs for NET G3 (P=0.049 for SUVT/B and P=0.026 for the number of metastatic lesions). In addition, statistical significance was found among osteogenesis group, osteolysis group, and the no-change group (for bone SUVT/B value detected by 18F-FDG and Ki-67 index, osteogenesis group < osteolysis group; for bone SUVT/B detected by 68Ga-DOTA-SSAs, osteogenesis group > the no-change group). What is more, liver and bone SUVmax and Ki-67 index were positively correlated in 18F-FDG imaging (P < 0.001 for liver; P=0.002 for bone), and negatively correlated in 68Ga-DOTA-SSAs imaging (P < 0.001 for liver; P=0.039 for bone). Conclusions: 68Ga-DOTA-SSAs was superior to 18F-FDG for detecting BMs in NET G1/G2 (well and moderately differentiated NETs), as well as in NET G3 (poorly differentiated NETs). Relatively good differentiation was observed in the osteogenesis group. In addition, dual-tracer PET/CT imaging results were observably correlated with tumor differentiation.

Development and validation of 68Ga-PSMA-11 PET/CT-based radiomics model to detect primary prostate cancer.

BACKGROUND: This study aimed to develop a novel analytic approach based on a radiomics model derived from 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT for predicting intraprostatic lesions in patients with prostate cancer (PCa). METHODS: This retrospective study included consecutive patients with or without PCa who underwent surgery or biopsy after 68Ga-PSMA-11 PET/CT. A total of 944 radiomics features were extracted from the images. A radiomics model was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm with tenfold cross-validation in the training set. PET/CT images for the test set were reviewed by experienced nuclear medicine radiologists. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated for the model and radiologists' results. The AUCs were compared. RESULTS: The total of 125 patients (86 PCa, 39 benign prostate disease [BPD]) included 87 (61 PCa, 26 BPD) in the training set and 38 (61 PCa, 26 BPD) in the test set. Nine features were selected to construct the radiomics model. The model score differed between PCa and BPD in the training and test sets (both P < 0.001). In the test set, the radiomics model performed better than the radiologists' assessment (AUC, 0.85 [95% confidence interval 0.73, 0.97] vs. 0.63 [0.47, 0.79]; P = 0.036) and showed higher sensitivity (model vs radiologists, 0.84 [0.63, 0.95] vs. 0.74 [0.53, 0.88]; P = 0.002). CONCLUSION: Radiomics analysis based on 68Ga-PSMA-11 PET may non-invasively predict intraprostatic lesions in patients with PCa.

177Lu-PSMA-I&T Radioligand Therapy for Treating Metastatic Castration-Resistant Prostate Cancer: A Single-Centre Study in East Asians.

Purpose: There is increasing evidence for convincing efficacy and safety of 177Lu-labled prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (PRLT) for metastatic castration-resistant prostate cancer (mCRPC). However, data are not available regarding the feasibility of 177Lu-labled PSMA-targeted RLT in East Asians. The present study summarized the first experience with 177Lu-PSMA-I&T therapy for mCRPC in China. Methods: Forty consecutive patients with mCRPC were enrolled from December 2019 to September 2021. Eligible patients received 177Lu-PSMA-I&T RLT at intervals of 8-12 weeks. Toxicity was assessed based on standardized physicians' reports and the Common Toxicity Criteria for Adverse Events criteria. Response to PRLT was evaluated according to the changes of prostate specific antigen (PSA) response and imaging response. Quality of life (QOL), Karnofsky performance status (KPS) and pain (visual analogue scale, VAS) were also evaluated. The impacts of baseline parameters on the therapeutic effects were explored by univariate and multivariate logistic regression analyses. Results: All patients underwent a total of 86 cycles of 177Lu-PSMA-I&T (range: 1-5 cycles) with dosages of 3.70-14.43GBq per cycle, with a median of 8 months followed up. Six patients (15%) developed mild reversible xerostomia during follow-up, and 28 patients (70%) experienced grade 1-4 bone marrow dysfunction. Changes in PSA were assessed after therapy, accompanied by the partial response (PR) in 25 patients (62.5%), the stable disease (SD) in 5 patients (12.5%), and the progressive disease (PD) in 10 patients (25%), respectively. QOL, KPS (%) and VAS scores were improved significantly due to treatment (P<0.05). Overweight and elevated AST, ALP, and LDH were associated with poor outcomes. Conclusions: 177Lu-PSMA-I&T achieves the favourable response and well tolerance in mCRPC, which associates with not only PSA decline but also with tumor remission including lymphadenopathy and bone metastasis. We also find that patients with overweight and high AST, ALP, and LDH should be cautious to undergo the PRLT. Large-cohort studies are warranted to confirm the initial findings and elucidate the survival benefit of the treatment.

Combined use of 177 Lu-DOTATATE peptide receptor radionuclide therapy and fluzoparib for treatment of well-differentiated neuroendocrine tumors: A preclinical study.

Peptide receptor radionuclide therapy (177 Lu-DOTATATE) causes DNA strand breaks and has been validated for well-differentiated neuroendocrine tumor treatment. Poly-(ADP-ribose)-polymerase inhibitors have also been used for malignant tumors with deficient DNA repair. We aimed to determine whether the poly-(ADP-ribose)-polymerase inhibitor fluzoparib could enhance the anti-tumor effects of 177 Lu-DOTATATE in neuroendocrine tumor cells and xenografts. The neuroendocrine characteristics of NCI-H727 bronchial carcinoid cells were evaluated by immunofluorescence staining. The synergistic effects of fluzoparib and 177 Lu-DOTATATE were evaluated by cell proliferation and flow cytometry assays. Tumor response and the side effects of combination therapy were also assessed in xenograft mice treated with 77 Lu-DOTATATE and fluzoparib alone or in combination. Somatostatin receptors were specifically expressed in NCI-H727 cells and tumor xenografts. 177 Lu-DOTATATE (22.20 MBq mL-1 ) and fluzoparib (50 µm) inhibited cell proliferation by 16.6% and 35.6%, respectively, compared to 73.2% in cells treated with their combination. Tumor cell proliferation was significantly suppressed by 177 Lu-DOTATATE (22.20 MBq mL-1 , 4.4-fold) and fluzoparib (50 µm, 2.1-fold). 177 Lu-DOTATATE caused cell cycle arrest mainly at G1 phase, whereas fluzoparib caused arrest at G2/M phase, and combined treatment with both agents caused cell cycle arrest at G1 phase, similar to 177 Lu-DOTATATE alone. The volume of tumor xenografts was reduced by 18.6% in mice receiving combined treatment, compared to 4.9% and 11.4% in mice treated with 177 Lu-DOTATATE or fluzoparib alone. Fluzoparib can potentiate the anti-tumor effect of 177 Lu-DOTATATE in NCI-H727 cells in a synergistic manner by arresting the cell cycle at G1 phase. Further preclinical and clinical studies are warranted to validate these findings.

Prediction of Biochemical Recurrence After Radical Prostatectomy Based on Preoperative 68Ga-PSMA-11 PET/CT.

PURPOSE: This study was designed to investigate the prognostic role of preoperative 68Ga-PSMA-11 PET/CT in predicting biochemical recurrence (BCR) of localized prostate cancer (PCa) after radical prostatectomy (RP). METHODS: A total of 77 biopsy-confirmed PCa patients with 68Ga-PSMA-11 PET/CT prior to RP were included. A PSMA-ligand PET/CT-based risk model with SUVmax, maximum diameter of the index tumor and T stage was developed for prediction of 2-year BCR using Cox regression analysis. Also, the efficacy of the developed risk model was compared with European Association of Urology risk stratification (D'Amico) and the Cancer of the Prostate Risk Assessment (CAPRA) score. C-index and calibration plot were used to assess discrimination and calibration with internal validation. RESULTS: With a median follow-up of 25 months, 23 (29.9%) patients experienced BCR within 2 years after RP. Patients experienced BCR had a significant higher PSA at diagnosis (p<0.001), a higher ISUP grade of biopsy (p=0.044), as well as a higher ISUP grade (p=0.001), a higher possibility of T3 diseases (p=0.001) and positive margin (p=0.008) on postoperative pathology. SUVmax, maximum diameter of the index tumor and T stage on preoperative PSMA-ligand PET/CT were significantly associated with BCR (all p<0.01). PSMA-ligand PET/CT-based risk model had a superior discrimination (c-index 78.5%) and good calibration at internal validation. The efficacy of this model in predicting 2-year BCR after RP was better, compared with CAPRA (c-index 66.3%) and D'Amico (c-index 66.2%). The addition of the PSMA-ligand PET/CT-derived variables also improved the efficacy of the existing models in predicting 2-year BCR (C-index of 78.9% for modified CAPRA and 79.3% for modified D'Amico, respectively). CONCLUSION: A PSMA-ligand PET/CT-based risk model showed good efficacy in predicting 2-year BCR after RP, which needed to be validated by further prospective studies.

Can 68Ga-PSMA-11 Positron Emission Tomography/Computerized Tomography Predict Pathological Response of Primary Prostate Cancer to Neoadjuvant Androgen Deprivation Therapy? A Pilot Study.

PURPOSE: We explored the role of 68Ga-PSMA-11 positron emission/computerized tomography as a predictor of pathological response to neoadjuvant androgen deprivation therapy combined with abiraterone for high risk prostate cancer. MATERIALS AND METHODS: A total of 45 patients with localized high risk prostate cancer who had serial 68Ga-PSMA-11 positron emission tomography/computerized tomography scans before and after 6 months of androgen deprivation therapy plus abiraterone neoadjuvant treatment followed by radical prostatectomy were included in this study. Complete pathological response or minimal residual disease <5 mm on whole mount histopathology was defined as favorable pathological response. The diagnostic performance of prostate specific antigen response and positron emission tomography/computerized tomography response for favorable pathological response was calculated. Univariable and multivariable logistic regression analyses of clinical and imaging variables were also performed to identify favorable pathological response. RESULTS: Compared to the prostate specific antigen response, positron emission tomography/computerized tomography response had a significantly higher specificity in diagnosing favorable pathological response (89.7% vs 62.1%, p=0.043). Preoperative nadir prostate specific antigen (OR 0.121, 95% CI 0.028-0.529, p=0.005), posttreatment maximum standardized uptake value (OR 7.072, 95% CI 2.035-24.579, p=0.002) and posttreatment tumor volume (OR 7.896, 95% CI 1.415-44.054, p=0.018) measured on positron emission tomography/computerized tomography were significantly associated with favorable pathological response in univariable logistic regression analysis. On multivariable logistic regression analysis, only posttreatment maximum standardized uptake value was found to be an independent predictor of favorable pathological response (OR 9.69, 95% CI 1.439-65.242, p=0.020). CONCLUSIONS: 68Ga-PSMA positron emission tomography/computerized tomography has a better diagnostic performance of pathological response to neoadjuvant treatment compared with prostate specific antigen, with maximum standardized uptake value being an independent predictive factor. This pilot study suggests that prostate specific membrane antigen positron emission tomography/computerized tomography may serve as a potential predictor of pathological response to neoadjuvant treatment.

68Ga-PSMA PET/CT targeted biopsy for the diagnosis of clinically significant prostate cancer compared with transrectal ultrasound guided biopsy: a prospective randomized single-centre study.

PURPOSE: 68Ga-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is valuable for detecting primary and recurrent prostatic lesions. This study aimed to evaluate the efficacy of 68Ga-PSMA-11 PET/CT as a triage tool for prostate biopsy (PSMA-TB) and compare with transrectal ultrasound-guided biopsy (TRUS-GB) for the diagnosis of clinically significant prostate cancer (csPCa). METHODS: This single-centre study randomly allocated 120 patients with elevated serum prostate-specific antigen (PSA) levels (> 4 ng/ml) to PSMA-PET or TRUS group. Patients with PSMA-avid lesions (SUVmax ≥ 8.0) underwent PSMA-TB via a single-puncture percutaneous transgluteal approach (n = 25), whilst patients with negative PSMA-PET underwent systematic TRUS-GB (n = 35). All patients in the TRUS group underwent TRUS-GB directly (n = 60). RESULTS: PCa and csPCa were detected in 26/60 (43.3%) and 24/60 (40.0%) patients in the PSMA-PET group and 19/60 (31.6%) and 15/60 (25.0%) in the TRUS group, respectively. In the PSMA-PET group, the detection rate of PCa and csPCa were significantly higher in PSMA-PET-positive than negative patients (PCa, 23/25 (92.0%) vs 3/35 (8.6%), P < 0.01; csPCa, 22/25 (88.0%) vs 2/35 (5.7%), P < 0.01). PSMA-TB detected significantly more PCa and csPCa than TRUS-GB in the TRUS controls (PCa, 21/25 (84.0%) vs 19/60 (31.6%), P < 0.01; csPCa, 20/25 (80.0%) vs 15/60 (25.0%), P < 0.01). PSMA-PET detected significantly more cases of csPCa amongst patients with PSA 4.0-20.0 ng/ml than TRUS (27.02% vs 8.82%, P < 0.05). No haematuria, urinary retention or pelvic infection was observed after PSMA-TB compare with TRUS-GB. CONCLUSIONS: 68Ga-PSMA-11 PET/CT is a feasible imaging technique that may serve as a triage tool for prostate biopsy, and may improve the detection rate of csPCa compared with TRUS-GB, especially in patients with serum PSA 4.0-20.0 ng/ml.

68Ga-PSMA-11 PET/CT combining ADC value of MRI in the diagnosis of naive prostate cancer: Perspective of radiologist.

Ga-PSMA-11 positron emission computed tomography /computed tomography (PET/CT) is more sensitive than magnetic resonance imaging (MRI) in detecting prostate cancer (PCa). We evaluated the value of Ga-PSMA-11 PET/CT with MRI in treatment-naive PCa.This retrospective study was approved by the hospital ethics committee. The MRI and Ga-PSMA-11 PET/CT imaging data of 63 cases of highly suspected PCa were enrolled in this study. The SUVmax and apparent diffusion coefficient (ADC), and their ratio, were assessed as diagnostic markers to distinguish PCa from benign disease.There were 107 prostate lesions detected in 63 cases. Forty cases with 64 malignant primary lesions were confirmed PCa, whereas 23 cases had 43 benign lesions. PSMA-avid lesions correlated with hypointense signal on ADC maps and hyperintense signal on diffusion-weighted imaging. The ADC of PCa was lower than that of benign lesions, and SUVmax and SUVmax/ADC of PCa was higher than that of benign lesions (P < .01). ADC had significant negative correlation with Gleason score (GS) and SUVmax, SUVmax, and SUVmax/ADC positively correlated with GS. From ROC analysis, we established cutoff values of ADC, SUVmax, and SUVmax/ADC at 1.02 × 10mm/s, 11.72, and 12.35, respectively, to differentiate PCa from benign lesions. The sensitivity, specificity, and AUC were 90.6%, 58.1%, and 0.816 for ADC, 67.2%, 97.7%, and 0.905 for SUVmax, and 81.2%, 88.4%, and 0.929 for SUVmax/ADC, respectively.Ga-PSMA-11 PET/CT combined with MRI offers higher diagnostic efficacy in the detection of PCa than either modality alone.

Clinical study of 99mTc-3P-RGD2 peptide imaging in osteolytic bone metastasis.

OBJECTIVE: To investigate the value of integrin αvß3 targeted imaging with 99mTc-HYNIC-PEG4-E[PEG4-c(RGDfk)]2 (99mTc-3P-RGD2) as a radiotracer in dectecting osteolytic bone metastases. METHODS: This is a retrospective study involving a cohort of 69 consecutive patients including 59 with lung cancer and 10 with other cancers. Patients were required to receive whole body scan (WBS) and regional SPECT/CT imaging with 99mTc-3P-RGD2 (RGD imaging) and 99mTc-MDP (MDP imaging) as a radiotracer successively within days. Final diagnosis was based on comprehensive assessment of all available data including case history, CT, MRI, SPECT/CT, PET/CT, histopathology and 6-12 months follow-up. Visual observation and semiquantitative analysis (T/N: tracer uptake ratio of osteolytic metastases to normal bone) of 99mTc-3P-RGD2 or 99mTc-MDP imaging were performed and their detective values for osteolytic metastases were compared. RESULTS: A total of 131 osteolytic metastatic lesions were retrospectively studied. Osteolytic metastases mainly presented as "hot region", occasionally as "cool or normal region" on RGD imaging. The detection sensitivity of RGD WBS for osteolytic metastases was significantly higher than that of 99mTc-MDP WBS (80.9% vs. 46.6%, p<0.01). The sensitivity increased to 96.2% (126/131) when combining with SPECT/CT. 99mTc-3P-RGD2 imaging also promoted the detection of unknown primary tumor, lymph node metastases and offered information for clinical staging. T/N of 99mTc-3P-RGD2 in lung adenocarcinoma osteolytic metastases showed no statistical difference compared with that in squamous-cell carcinoma (6.84±3.46 vs. 7.33±3.22, t = 0.39, p = 0.71). Whereas, it was higher in osteolytic metastases from lung cancer than that from thyroid cancer (7.05±3.01 vs. 4.11±2.67, p = 0.03). CONCLUSION: 99mTc-3P-RGD2 peptide imaging showed great potential for detection of osteolytic bone metastasis due to high expression level of integrin αvß3 on osteoclast and most tumor cells.

Comparison of 68Ga-PSMA-11 PET-CT with mpMRI for preoperative lymph node staging in patients with intermediate to high-risk prostate cancer.

BACKGROUND: To evaluate the diagnostic value of 68Ga-PSMA-11 PET-CT with multiparametric magnetic resonance imaging (mpMRI) for lymph node (LN) staging in patients with intermediate- to high-risk prostate cancer (PCa) undergoing radical prostatectomy (RP) with pelvic lymph node dissection (PLND). METHODS: We retrospectively identified 42 consecutive patients with intermediate- to high-risk PCa according to D'Amico and without concomitant cancer. Preoperative 68Ga-PSMA-11 PET-CT, pelvic mpMRI and subsequent robot assisted laparoscopic RP with PLND were performed in all patients. RESULTS: Among 42 patients assessed, the preoperative PSA value, Gleason score, pT stage and intraprostatic PCa volume of patients with LN metastases were all significantly higher than those without metastases (P = 0.029, 0.028, 0.004, respectively). The average maximum standardized uptake value (SUV) of 68Ga-PSMA-11 PET-CT positive PCa of patients with or without LN metastases were 13.10 (range 6.12-51.75) and 7.22 (range 5.4-11.2), respectively (P < 0.001). 68Ga-PSMA-11 PET-CT and pelvic mpMRI had the ability of succeed on preoperative definite accurate diagnosis and accurate localization of primary PCa in all 42 patients. Fifteen patients (35.71%) had a pN1 stage. 51 positive LN were found. Both 68Ga-PSMA-11 PET-CT and pelvic mpMRI displayed brillient patient-based and region-based sensitivity, specificity, negative predictive value and positive predictive value. There was no statistical difference for the detection of LNMs according to the diameter of the LNMs between 68Ga-PSMA-11 PET-CT and mpMRI in this study. CONCLUSIONS: Both 68Ga-PSMA-11 PET-CT and mpMRI performed great value for LN staging in patients with intermediate- to high-risk PCa undergoing RP with PLND. However, despite excellent performance of 68Ga-PSMA-11 PET-CT, it cannot replace mpMRI that remains excellent for lymph node staging.

68Ga-PSMA-11 PET/CT for prostate cancer staging and risk stratification in Chinese patients.

We evaluated the clinical utility of 68Ga-PSMA-11 PET/CT for staging and risk stratification of treatment-naïve prostate cancer (PCa) and metastatic castrate-resistant prostate cancer (mCRPC). Twenty-two consecutive patients with treatment-naïve PCa and 18 with mCRPC were enrolled. 68Ga-PSMA-11 PET/CT and magnetic resonance imaging (MRI) were performed for the evaluation of primary prostatic lesions, and bone scans were used for evaluation bone metastasis. Among the 40 patients, 37 (92.5% [22 treatment-naïve PCa, 15 mCRPC]) showed PSMA-avid lesions on 68Ga-PSMA-11 images. Only 3 patients with stable mCRPC after chemotherapy were negative for PSMA. The sensitivity, specificity and accuracy of 68Ga-PSMA-11 imaging were 97.3%, 100.0% and 97.5%, respectively. The maximum standardized uptake (SUVmax) of prostatic lesions was 17.09 ± 11.08 and 13.33 ± 12.31 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 revealed 105 metastatic lymph nodes in 15 patients; the SUVmax was 16.85 ± 9.70 and 7.54 ± 5.20 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 PET/CT also newly detected visceral metastasis in 9 patients (22.5%) and bone metastasis in 29 patients (72.5%). 68Ga-PSMA-11 PET/CT exhibits potential for staging and risk stratification in naïve PCa, as well as improved sensitivity for detection of lymph node and remote metastasis.