Data pooling was accomplished through a random-effects meta-analysis, and the I2 index was employed to assess heterogeneity. Thirty-nine case studies, which comprised 1259 patients, were included to explore the utility of FAPI PET/CT. In a patient-centered analysis, the pooled sensitivity for identifying primary lesions was 0.99 (95% CI, 0.97-1.0). Combining the data, the sensitivity for nodal metastases was 0.91 (95% CI, 0.81-0.96) and for distant metastases 0.99 (95% CI, 0.96-1.00). FAPI demonstrated increased sensitivity compared to [18F]FDG PET/CT in the detection of primary, nodal, and metastatic lesions in a paired analysis, achieving statistical significance (all p < 0.001). The comparison of FAPI and [18F]FDG sensitivities yielded a statistically significant result. In terms of diversity, the evaluation of primary lesions was moderately affected, remote tumor spread was highly impacted, and the investigation of lymph node metastasis displayed minimal heterogeneity. FAPI PET/CT's diagnostic superiority over [18F]FDG lies in its enhanced ability to detect primary, nodal, and distant metastases. Further investigation is crucial to assess the practical value and appropriate applications of this method across various cancer types and clinical contexts.
After receiving [177Lu]Lu-DOTATATE to treat neuroendocrine neoplasms, a common side effect is bone marrow suppression. Radioactive uptake in the radiosensitive red marrow, a location where CD34-positive hematopoietic progenitor cells and neuroendocrine neoplasms are both present, is a possible consequence of the shared expression of somatostatin receptor type 2. This study sought to determine and measure the precise uptake of red marrow, leveraging SPECT/CT imaging acquired following the initial treatment cycle. [177Lu]Lu-DOTATATE was administered to seventeen patients who had been diagnosed with neuroendocrine neoplasms. Seven cases presented with confirmed bone metastases. Four SPECT/CT imaging sessions were part of each patient's protocol, performed at 4, 24, 48, and 168 hours post-first treatment cycle. The concentrations of activity within tumors and multiple skeletal sites presumed to contain red marrow, particularly the T9-L5 vertebrae and the ilium of the hip, were calculated by employing Monte Carlo-based reconstructions. To establish a pure red marrow biodistribution, a compartment model used the descending aorta's activity concentration as input data. This separated the blood-derived, non-specific activity from the specific activity concentration in the red marrow. By means of the compartment model's biodistribution data, red marrow dosimetry was executed at each specific skeletal site. All 17 patients demonstrated an elevated uptake of [177Lu]Lu-DOTATATE within the T9-L5 vertebrae and hip bones, when contrasted with activity levels in the aorta. Compared to nonspecific uptake, the average red marrow uptake was 49% greater (a range of 0% to 93%). The mean absorbed dose to the red marrow in the vertebrae was 0.00430022 Gy/GBq, whereas the corresponding median dose in the hip bones was 0.00560023 Gy/GBq. Among patients with bone metastases, the absorbed dose was 0.00850046 Gy/GBq for vertebrae and 0.00690033 Gy/GBq for the hip bones primed transcription Statistically, the red marrow elimination rate was slower in patients with fast tumor elimination, this being consistent with transferrin-mediated transport of 177Lu back to the red marrow. The observed uptake of [177Lu]Lu-DOTATATE in the red marrow mirrors the presence of somatostatin receptor type 2-expressing hematopoietic progenitor cells, according to our findings. The process of eliminating specific substances, a time-consuming one, is not accounted for in blood-based dosimetry methods, thereby leading to an underestimation of the dose absorbed by the red bone marrow.
Prospective, multicenter, randomized phase II TheraP study results showed encouraging outcomes for prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) in the management of metastatic castration-resistant prostate cancer (mCRPC). Participants were eligible for the study provided that a pretherapeutic 68Ga-PSMA-11 PET scan showed satisfactory tumor uptake exceeding a defined threshold, along with the absence of any 18F-FDG-positive, PSMA ligand-negative tumor lesions. While these PET-based inclusion criteria may hold prognostic value, its exact impact is currently unclear. As a result, the efficacy on mCRPC patients undergoing PSMA RLT therapy was examined, encompassing the TheraP approach, as well as other TheraP-related PET criteria for inclusion. Patients were initially grouped into two categories: those with PSMA PET scans showing TheraP contrast-enhanced PSMA PET-positive (cePSMA) and those with TheraP cePSMA PET-negative scans, both adhering to the inclusion criteria of the TheraP study. Our patients did not undergo 18F-FDG PET imaging, in marked divergence from the TheraP procedures. Evaluations were conducted to compare the prostate-specific antigen (PSA) response, (specifically a 50% reduction in PSA from the baseline level), PSA progression-free survival, and overall survival (OS). Molecular Biology Reagents Patients were subsequently categorized into two groups based on SUVmax cut-offs that were distinct from those used in TheraP, to ascertain their potential impact on treatment outcome. This study encompassed 107 mCRPC patients, categorized as follows: 77 exhibiting TheraP cePSMA PET positivity and 30 exhibiting TheraP cePSMA PET negativity. Patients with positive TheraP cePSMA PET scans demonstrated a substantially greater response to PSA treatment than those with negative scans, showing rates of 545% compared to 20% (P = 0.00012). A statistically significant difference was observed in median progression-free survival (P = 0.0007) and overall survival (P = 0.00007) between patients in the TheraP cePSMA PET-positive and PET-negative groups, with superior survival times in the former group. Importantly, the presence of TheraP cePSMA PET positivity was a noteworthy predictor for a longer overall survival (OS), with a statistically significant association (P = 0.0003). Patients qualifying for PSMA RLT showed no variation in outcome when subjected to different SUVmax thresholds for their hottest lesion. In our pre-selected patient group undergoing PSMA RLT, adherence to TheraP's inclusion criteria correlated with a more favorable treatment response and outcome. Nevertheless, a considerable portion of patients who did not meet these criteria still experienced notable response rates.
The FALCON software, a fast motion correction algorithm, is designed for dynamic whole-body PET/CT scans, providing correction for both rigid and nonlinear motion, irrespective of the specific PET/CT system or the tracer used. Affine alignment was applied initially to Methods motion, followed by the introduction of a diffeomorphic approach to handle any non-rigid deformations that remained. Using multiscale image alignment, images were registered in both steps. Additionally, the frames that facilitated successful motion correction were automatically calculated based on the initial normalized cross-correlation metric, comparing the reference frame with the other moving frames. To assess the efficacy of motion correction, we examined dynamic PET/CT image sequences from three distinct systems (Biograph mCT, Biograph Vision 600, and uEXPLORER), leveraging six diverse radiotracers (18F-FDG, 18F-fluciclovine, 68Ga-PSMA, 68Ga-DOTATATE, 11C-Pittsburgh compound B, and 82Rb). Motion correction accuracy was evaluated using four different parameters: volume discrepancy shifts between individual whole-body (WB) image volumes, to assess gross body motion; displacement variations in a large organ (the liver dome) within the torso caused by respiration; intensity variations in minute tumor nodules due to motion blurring; and consistency of activity concentration levels. By implementing motion correction, the volume mismatch across dynamic frames and gross body motion artifacts were mitigated by approximately 50%. Additionally, the assessment procedure for large-organ motion correction was based on the effectiveness of correcting liver dome motion; this was completely eliminated in around 70% of examined cases. An average rise in tumor SUV values of 15% was achieved through motion correction, further enhancing tumor intensity. PJ34 in vivo Despite the considerable deformations evident in gated cardiac 82Rb images, the subsequent images remained free from anomalous distortions and substantial intensity changes. Finally, the activity concentrations in major organs remained quite steady (displaying a variation of less than 2%) in the pre and post-motion correction periods. Falcon's ability to swiftly and precisely correct rigid and non-rigid motion artifacts in whole-body PET scans makes it highly adaptable to diverse imaging situations, regardless of scanner specifics or tracer distribution.
Patients with prostate cancer slated for systemic treatment who carry excess weight tend to have longer overall survival; conversely, sarcopenia in these patients is linked to a reduced overall survival. We examined fat-related and body composition metrics in prostate-specific membrane antigen (PSMA)-RLT recipients to evaluate their prognostic significance for overall survival (OS). Among the 171 patients pre-scheduled for PSMA-directed radiotherapy (RLT), BMI (kg/m^2), and CT-scan obtained body composition parameters—total, subcutaneous, visceral fat area, and psoas muscle area at L3-L4 level—were evaluated. To account for stature, the psoas muscle index was utilized to characterize sarcopenia. To determine the outcome, Kaplan-Meier curves and Cox regression were applied, considering fat-related parameters and other clinical variables including Gleason score, C-reactive protein (CRP), lactate dehydrogenase (LDH), hemoglobin, and prostate-specific antigen levels. The Harrell C-index served as the metric for goodness-of-fit analysis. Among the patient cohort, sarcopenia was diagnosed in 65 individuals (38%), and 98 individuals (573%) presented with elevated BMI.