Nuclear Medicine Communications最新文献

Purpose: The purpose of this study was to evaluate and quantify the prevalence of increased uptake in SPECT/CT in symptomatic and asymptomatic foot and ankle joints in patients with osteoarthritis.

Methods: In 63 patients with osteoarthritis (OA), the painful symptomatic foot (SF) and asymptomatic contralateral foot (AF) were imaged with bone SPECT/CT. Presence, localization, and maximum standardized uptake value (SUVmax) of the active joints were assessed for SF and AF. CT OA grade (grade 1: mild, grade 2: moderate, grade 3: severe) and presence of five morphological features of OA (joint space narrowing, subchondral sclerosis, subchondral cysts, irregular joint margins, and osteophytes) were evaluated.

Results: In total 32 (51%) patients showed additional uptake in the AF, whereas 31 (49%) patients showed it only in the SF. SF showed more active joints than AF (106 vs. 43). CT OA grades positively correlated with SUVmax (Kendall's tau b = 0.62, P < 0.001). SUVmax values (per foot) in SF were higher in patients with uptake in bilateral feet (SF+, AF+) [median (IQR): 17.9 (10.7-23.3)] as compared with patients with active sites only in the SF (SF+, AF-) [10.4 (6.4-19.1); P < 0.001]. Number of active OA joints in SF was higher in patients with bilateral uptake (P = 0.017).

Conclusion: In conclusion, half of the patients exhibited increased uptake in the contralateral asymptomatic foot. SUVmax showed a significant correlation to CT osteoarthritis grade, in the symptomatic and asymptomatic foot. Future follow-up studies will provide further insights into the prognostic and therapeutic value of these findings.

Objective: To investigate the relationship between intraprostatic 68Ga-prostate-specific membrane antigen (PSMA) uptake values and volumetric parameters derived from early pelvic and standard-time whole-body 68Ga-PSMA PET/computed tomography (CT) images in untreated prostate cancer (PCa) patients, and to assess the predictive significance of these data in relation to disease prognosis, comparing them with the Gleason score, clinical risk classification and the presence of metastatic disease detected in 68Ga-PSMA PET/CT imaging.

Methods: Eighty-one newly diagnosed PCa patients underwent early phase pelvic imaging at the 5th minute and standard time whole-body imaging at the 60th minute. Various threshold values were used in intraprostatic delineations to compute maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), intraprostatic PSMA tumor volume and intraprostatic total lesion PSMA uptake. Correlations between early and standard time measurements, as well as changes in SUV parameters over time, were examined. The association of these values with Gleason score, clinical risk status (National Comprehensive Cancer Network), and metastatic disease was explored.

Results: SUVmax measurements from both early and standard time images distinguished all three groups (clinical risk scores, Gleason score and metastatic group), with standard imaging demonstrating statistical superiority in receiver operating characteristic analyses. Strong correlations were observed between early and standard-time PET parameters. Changes in intraprostatic SUVmax and SUVmean values over time did not exhibit predictive value.

Conclusion: Although intraprostatic PSMA PET parameters generally aligned at both early and standard times, parameters obtained from standard time images showed more robust correlations with clinical risk scores, Gleason score and metastasis status in newly diagnosed, untreated PCa patients.

Aim: The early detection of prostate cancer (PCa) metastatic disease with PET imaging leads to stage migration and change of disease management. We aimed to assess the impact on clinical management deriving from prostate-specific membrane antigen (PSMA) imaging with a digital PET/CT during the routine application in the staging and restaging process of PCa.

Material and methods: Eighty consecutive PCa patients underwent 18F-PSMA-1007. Digital PET/CT were retrospectively evaluated and discussed with oncologists to evaluate the impact on clinical management. Performances analysis, correlation among variables also considering semiquantitative parameters have been conducted.

Results: In the whole group of 80 patients at staging (N = 31) and restaging (N = 49), the detection rate of PSMA PET was 85% for all lesions. At staging, the performance analysis resulted in sensitivity 77.6%, specificity 89.5%, negative predictive value (NPV) 77.6%, positive predictive value (PPV) 89.5%, accuracy 85.7%, and area under curve (AUC) 0.87%. The performance of restaging PET in the group of patients with PSA values <1 ng/ml resulted in the following values: sensitivity 66.7%, specificity 92.9%, NPV 85.7%, PPV 81.3%, accuracy 82.6%, and AUC 0.79. Semiquantitative analysis revealed a mean value of SUVmax, metabolic tumor volume, and total lesion PSMA expression with differences in patients with high risk compared to low intermediate. At restaging PET, semiquantitative values of patients with total prostate specific antigen (tPSA) ≤ 1 ng/ml were significantly less than those of the tPSA > 1 ng/ml. A significant impact on clinical management was reported in 46/80 patients (57.5%) based on PSMA PET findings at staging and restaging.

Conclusion: Although PSMA-PET provides optimal performances, its current role in redefining a better staging should be translated in the current clinical scenario about potential improvement in clinical/survival outcomes.

Objective: The aim of this study was to evaluate the biodistribution and dosimetry of lutetium-177-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (177Lu-DOTA)-rituximab in CD20+ non-Hodgkin's lymphoma and other hematological malignancies treated with rituximab.

Methods: The standard dosimetry protocol was used, with cold rituximab infusion, then a diagnostic activity of 177Lu-DOTA-rituximab. Planar images were acquired at multiple time points. Normal organs and tumor dosimetry were performed by using organ and tumor-specific regions of interest and whole-body counts were obtained serially after pixel matched, background, scatter, and attenuation correction. The mean radiation absorbed doses were obtained from OLINDA/EXM v2.1.1 and ORIGIN software.

Results: A total of 22 patients were included in this study. Prolonged blood pool clearance of 177Lu-DOTA-rituximab with long residence time in the blood pool and normal organs were observed. The whole body effective half-life was 104.5 ± 22 h. The mean total body radiation absorbed dose was 0.208 ± 0.03 mGy/MBq and the mean total body effective dose was 0.196 ± 0.05 mGy/MBq of 177Lu-DOTA-rituximab. The mean radiation absorbed doses of 0.613 ± 0.21, 1.68 ± 2, 1.01 ± 0.42, and 0.136 ± 0.02mGy/MBq were seen for the liver, spleen, kidneys, and bone marrow, respectively. Tumor lesion uptake was noticed in two patients with tumor radiation absorbed doses were 0.842 mGy/MBq in one and 9.9 mGy/MBq in the other patient. A strong correlation was obtained between the cumulative activities of radiation-absorbed doses derived from ORIGIN and OLINDA software methods at a significant P value less than 0.001.

Conclusion: The results of our study demonstrated favorable biodistribution and dosimetry of indigenously produced 177Lu-DOTA-rituximab in patients with CD20+ lymphoma. These results can be used for future studies of radioimmunotherapy employing 177Lu-DOTA-rituximab.

Objective: This study aimed to explore and compare the utility of baseline 18F-PSMA-1007 and 68Ga-PSMA-11 PET/computed tomography (CT) derived volumetric parameters in initial risk stratification and prediction of prostate cancer (PCa) metastasis.

Methods: Forty treatment-naïve, biopsy-proven intermediate-/high-risk PCa patients were prospectively recruited. Each patient underwent PET/CT with 68Ga-PSMA-11 and 18F-PSMA-1007 (within 2 weeks). The maximum and mean standardized uptake values (SUVmax and SUVmean) of primary tumor, prostate PSMA-tumor volume (PSMA-TVp), and prostate total lesion PSMA (TL-PSMAp) were measured.

Results: PSMA-TVp and TL-PSMAp (with both radiotracers) mostly exhibited moderate-to-strong correlation with Gleason score, serum prostate-specific antigen level and clinical tumor stage (Spearman ρ = 0.361-0.783, P-values ≤0.022). Primary tumor SUVmax values were similar across initial risk categories. PSMA-TVp and TL-PSMAp, however, were significantly higher in high-risk PCa compared to intermediate-risk PCa (P-values ≤0.001). Receiver operating characteristic (ROC) curve analysis revealed that F-PSMA-TVp, Ga-PSMA-TVp, F-TL-PSMAp, and Ga-TL-PSMAp (optimal cutoff values of 20.9, 23.4, 142.5, and 144.8, respectively) could effectively differentiate high-risk from intermediate-risk PCa [area under the ROC curve (AUCs) 0.859-0.898, P-values <0.001] with high sensitivity (~68.8-75%) and excellent specificity (100%). PSMA-TVp and TL-PSMAp (with both radiotracers) could predict presence of regional and extraregional nodal metastasis (AUCs 0.703-0.801, P-values ≤0.03) with moderate sensitivity (~47.8-70.6%) and excellent specificity (~82.6-94.1%).

Conclusion: Our results suggest that baseline PSMA-PET primary tumor volumetric parameters provide a noninvasive, objective, and accurate index for initial risk stratification and can predict presence of regional and extraregional nodal metastasis in PCa patients. Larger studies are warranted to evaluate their incremental role over conventional parameters.

Purpose: The purpose of this study is to compare the value of absolute renal uptake (ARU %) in patients by using Tc-99m MAG-3 and Tc-99m DMSA scan.

Material and methods: Absolute renal uptake is calculated using Tc-99m MAG-3 and Tc-99m DMSA in renal scintigraphy, Itoh and Tauex kidney depth methods used, respectively. n = 40 adult patients of both genders were included. All patients underwent Tc-99m MAG-3 and Tc-99m DMSA, respectively.

Results: The values of ARU (%) were calculated separately in selected patients n = 40, (left = 17, right = 23 normal functioning kidneys) by MAG-3 and DMSA. Absolute renal uptake (%) of Tc-99m MAG-3 in left kidneys was found to be 15.2 ± 3.4, with spilt renal function 79.2 ± 14.7 and ARU (%) in right kidneys 16.2 ± 3.4 with spilt renal function 77.5 ± 19. Absolute renal uptake of Tc-99m DMSA in left kidneys was 17.5 ± 3.2 and in right kidneys 17.9 ± 4.5 with spilt renal function 81.8 ± 10.7 and 79.3 ± 13.8 for left and right kidney, respectively. Statistical analysis showed strong Pearson correlation.

Conclusion: Absolute renal uptake % was found to be more reliable in cases of bilateral compromised kidneys. ARU (%) calculated by Tc-99m MAG-3 solely can be used as predictor of renal function. The use of Tc-99m MAG-3 has more advantages than Tc-99m DMSA alone in renal scintigraphy as dynamic scintigraphy gives less radiation burden to patient, more information regarding renal function, and shorter stay time at hospital in comparison to static renal imaging. SRF % is less reliable than ARU (%).