Diagnostic Performance and Clinical Impact of 68Ga-PSMA-11 PET/CT Imaging in Early Relapsed Prostate Cancer After Radical Therapy: A Prospective Multicenter Study (IAEA-PSMA Study).

Biochemical recurrence (BCR) is a clinical challenge in prostate cancer (PCa) patients, as recurrence localization guides subsequent therapies. The use of PET with prostate-specific membrane antigen (PSMA) provides better accuracy than conventional imaging practice. This prospective, multicenter, international study was performed to evaluate the diagnostic performance and clinical impact of PSMA PET/CT for evaluating BCR in PCa patients in a worldwide scenario. Methods: Patients were recruited from 17 centers in 15 countries. Inclusion criteria were histopathologically proven prostate adenocarcinoma, previous primary treatment, clinically established BCR, and negative conventional imaging (CT plus bone scintigraphy) and MRI results for patients with PSA levels of 4-10 ng/mL. All patients underwent PET/CT scanning with 68Ga-PSMA-11. Images and data were centrally reviewed. Multivariate logistic regression analysis was applied to identify the independent predictors of PSMA-positive results. Variables were selected for this regression model on the basis of significant associations in the univariate analysis and previous clinical knowledge: Gleason score, the PSA level at the time of the PET scan, PSA doubling time, and primary treatment strategy. All patients were monitored for a minimum of 6 mo. Results: From a total of 1,004 patients, 77.7% were treated initially with radical prostatectomy and 22.3% were treated with radiotherapy. Overall, 65.1% had positive PSMA PET/CT results. PSMA PET/CT positivity was correlated with the Gleason score, PSA level at the time of the PET scan, PSA doubling time, and radiotherapy as the primary treatment (P < 0.001). Treatment was modified on the basis of PSMA PET/CT results in 56.8% of patients. PSMA PET/CT positivity rates were consistent and not statistically different among countries with different incomes. Conclusion: This multicenter, international, prospective trial of PSMA PET/CT confirmed its capability for detecting local and metastatic recurrence in most PCa patients in the setting of BCR. PSMA PET/CT positivity was correlated with the Gleason score, PSA level at the time of the PET scan, PSA doubling time, and radiotherapy as the primary treatment. PSMA PET/CT results led to changes in therapeutic management in more than half of the cohort. The study demonstrated the reliability and worldwide feasibility of PSMA PET/CT in the workup of PCa patients with BCR.

Practice and prospects for PET/CT guided interventions.

During the past 10 years, performing real-time molecular imaging with positron emission tomography (PET) in combination with computed tomography (CT) during interventional procedures has undergone rapid development. Keeping in mind the interest of the nuclear medicine readers, an update is provided of the current workflows using real-time PET/CT in percutaneous biopsies and tumor ablations. The clinical utility of PET/CT guided biopsies in cancer patients with lung, liver, lymphoma, and bone tumors are reviewed. Several technological developments, including the introduction of new PET tracers and robotic arms as well as opportunities provided through acquiring radioactive biopsy specimens are briefly reviewed.

PET/CT-Guided Biopsy of Suspected Lung Lesions Requires Less Rebiopsy Than CT-Guided Biopsy Due to Inconclusive Results.

The purpose of this study was to compare 18F-FDG PET/CT and CT performance in guiding percutaneous biopsies with histologic confirmation of lung lesions. Methods: We prospectively evaluated 341 patients, of whom 216 underwent 18F-FDG PET/CT-guided biopsy and 125 underwent CT-guided biopsy. The pathology results, lesion size, complications, and rebiopsy rate in the 2 groups were evaluated. Results: Of the 216 biopsies with PET/CT guidance, histology demonstrated 170 lesions (78.7%) to be malignant and 46 (21.3%) to be benign. In the CT-guided group, of 125 lesions, 77 (61.6%) were malignant and 48 (38.4%) were benign (P = 0.001). Inconclusive results prompted the need for a second biopsy in 18 patients: 13 of 125 (10.4%) in the CT group and 5 of 216 (2.3%) in PET group (P = 0.001). Complications were pneumothorax (13.2%), hemothorax (0.8%), and hemoptysis (0.6%). No life-threatening adverse events or fatalities were reported. The difference in complication rates between the 2 groups was not significant (P = 0.6). Malignant lesions showed a greater mean size than benign lesions regardless of the group (P = 0.015). Conclusion: PET/CT-guided biopsy of lung lesions led to fewer inconclusive biopsies than CT-guided biopsy, with similar complication rates.

Fluorodeoxyglucose-positron emission tomography staging can replace bone marrow biopsy in Hodgkin's lymphoma. Results from Brazilian Hodgkin's Lymphoma Study Group

ABSTRACT Objective: To investigate, in a large prospective multicenter study, whether 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography is sufficiently accurate to identify clinically important bone marrow involvement by Hodgkin's lymphoma to replace routine bone marrow biopsy in a developing tropical country. Methods: Patients newly diagnosed with Hodgkin's lymphoma were recruited from six cancer centers in Brazil. All were staged by the results of positron emission tomography/computed tomography that were centrally reviewed and by iliac crest bone marrow biopsy. Patients were classified as having marrow disease if they had lymphoma identified by marrow biopsy histology or had focal 2-[18F]-fluoro-2-deoxy-D-glucose marrow uptake that resolved following chemotherapy. Results: A total of 246 participants were recruited from six different centers and 62 (25.2%) were judged to have Hodgkin's lymphoma in the bone marrow. Positron emission tomography and biopsies were concordant in 206 patients (83%). Positron emission tomography correctly identified marrow disease in 59/62 patients (95.1%) and marrow biopsy in 25/62 patients (40.3%). In 22/62 (35.4%) patients, the two techniques were concordant in the diagnosis of marrow involvement. Of the forty discordant results, positron emission tomography found bone marrow involvement in 37 patients, upstaging 22 to stage IV and having an impact on therapeutic decision in nine cases given their reallocation from early to advanced stage. Three false negative positron emission tomography results were obtained with bone marrow biopsy giving positive findings. All three cases were classified as stage IV regardless of bone marrow findings implying no modification in the clinical management. The sensitivity, specificity and accuracy of positron emission tomography for detecting bone marrow disease were 95%, 100% and 98% and for bone marrow biopsy they were 40%, 100% and 84%, respectively. Conclusion: We conclude that positron emission tomography can replace marrow biopsy in Brazilian patients with Hodgkin's lymphoma without compromising clinical management.

Fluorodeoxyglucose-positron emission tomography staging can replace bone marrow biopsy in Hodgkin's lymphoma. Results from Brazilian Hodgkin's Lymphoma Study Group.

OBJECTIVE: To investigate, in a large prospective multicenter study, whether 2-[18F]-fluoro-2-deoxy-d-glucose-positron emission tomography is sufficiently accurate to identify clinically important bone marrow involvement by Hodgkin's lymphoma to replace routine bone marrow biopsy in a developing tropical country. METHODS: Patients newly diagnosed with Hodgkin's lymphoma were recruited from six cancer centers in Brazil. All were staged by the results of positron emission tomography/computed tomography that were centrally reviewed and by iliac crest bone marrow biopsy. Patients were classified as having marrow disease if they had lymphoma identified by marrow biopsy histology or had focal 2-[18F]-fluoro-2-deoxy-d-glucose marrow uptake that resolved following chemotherapy. RESULTS: A total of 246 participants were recruited from six different centers and 62 (25.2%) were judged to have Hodgkin's lymphoma in the bone marrow. Positron emission tomography and biopsies were concordant in 206 patients (83%). Positron emission tomography correctly identified marrow disease in 59/62 patients (95.1%) and marrow biopsy in 25/62 patients (40.3%). In 22/62 (35.4%) patients, the two techniques were concordant in the diagnosis of marrow involvement. Of the forty discordant results, positron emission tomography found bone marrow involvement in 37 patients, upstaging 22 to stage IV and having an impact on therapeutic decision in nine cases given their reallocation from early to advanced stage. Three false negative positron emission tomography results were obtained with bone marrow biopsy giving positive findings. All three cases were classified as stage IV regardless of bone marrow findings implying no modification in the clinical management. The sensitivity, specificity and accuracy of positron emission tomography for detecting bone marrow disease were 95%, 100% and 98% and for bone marrow biopsy they were 40%, 100% and 84%, respectively. CONCLUSION: We conclude that positron emission tomography can replace marrow biopsy in Brazilian patients with Hodgkin's lymphoma without compromising clinical management.

Comparison of CT and PET/CT for biopsy guidance in oncological patients.

PURPOSE: To compare FDG PET/CT and CT for the guidance of percutaneous biopsies with histological confirmation of lesions. METHODS: We prospectively evaluated 323 patients of whom 181 underwent FDG PET/CT-guided biopsy (total 188 biopsies) and 142 underwent CT-guided biopsy (total 146 biopsies). Biopsies were performed using the same PET/CT scanner with a fluoroscopic imaging system. Technical feasibility, clinical success and complication rates in the two groups were evaluated. RESULTS: Of the 188 biopsies with PET/CT guidance, 182 (96.8%) were successful with conclusive tissue samples obtained and of the 146 biopsies with CT guidance, 137 (93.8%) were successful. Therefore, 6 of 188 biopsies (3.1%) with PET/CT guidance and 9 of 146 (6.1%) with CT guidance were inconclusive (p = 0.19). Due to inconclusive histological results, 4 of the 188 lesions (2.1%) were rebiopsied with PET/CT guidance and 3 of 146 lesions (2.0%) were rebiopsied with CT guidance. Histology demonstrated that 142 of 188 lesions (75.5%) were malignant, and 40 (21.2%) were benign in the PET/CT-guided group, while 89 of 146 lesions (60.9%) were malignant and 48 (32.8%) were benign in the CT-guided group (p = 0.004 and 0.01, respectively). Patients with a histological diagnosis of benign lesion had no recurrence of disease with a minimum of 6 months follow-up. Of the 188 PET/CT-guided biopsies, 6 (3.1%) were repeat biopsies due to a previous nondiagnostic CT-guided biopsy performed in a different diagnostic centre. The interval between the two biopsies was less than a month in all cases. Histology revealed five malignant lesions and one benign lesion among these. The complication rate in the PET/CT-guided biopsy group was 12.7% (24 of 188), while in the CT-guided group, was 9.5% (14 of 146, p = 0.26). Therefore, there was no significant difference in complication rates between PET/CT and CT guidance. CONCLUSION: PET/CT-guided biopsy is already known to be a feasible and accurate method in the diagnostic work-up of suspected malignant lesions. This prospective analysis of a large number of patients demonstrated the feasibility and advantages of using PET/CT as the imaging method of choice for biopsy guidance, especially where FDG-avid foci do not show corresponding lesions on the CT scan. There were no significant differences in the ability to obtain a diagnostic specimen or in the complication rates between PET/CT and CT guidance.

Fluorodeoxyglucose-PET/Computed Tomography-Guided Biopsy.

PET/computed tomography (CT) combines the anatomic information from CT with PET metabolic characterization. 18F-fluorodeoxyglucose (FDG) PET is helpful to differentiate malignant lesions from benign ones, that usually show lower or no uptake. However, active inflammation or infectious disease might also present FDG uptake. Studies confirm the great value of PET/CT as the imaging method of choice for guiding biopsy procedures. Novel PET radiopharmaceuticals are also being investigated for guiding biopsies.