Prediction of clinically significant prostate cancer by [68 Ga]Ga-PSMA-11 PET/CT: a potential tool for selecting patients for active surveillance.

PURPOSE: In our study, our aim was to investigate the role of [68 Ga]Ga-PSMA-11 PET /CT imaging in the diagnosis of clinically significant prostate cancer (csPCa) (ISUP GG 2 and higher) in patients initially diagnosed with ISUP GG 1 and 2 after prostate biopsy. MATERIALS AND METHODS: We retrospectively reviewed 147 patient records in whom [68 Ga]Ga-PSMA-11 PET/CT imaging was performed preoperatively. All patients were initially diagnosed with ISUP GG 1 and 2 PCa by biopsy. Final pathology reports were obtained after radical prostatectomy. The [68 Ga]Ga-PSMA-11 PET/CT images were evaluated to determine the PRIMARY score. Patients' mpMRI-PIRADS scores were also recorded when available and analyzed in correlation with the pathology results. RESULTS: For the 114 patients scored using PRIMARY, 19 out of 37 patients with scores of 1 and 2 (51%) were diagnosed with csPCa. Of the 77 patients with PRIMARY scores between 3 and 5, 64 (83%) had csPCa. Notably, every patient with a PRIMARY score of 5 had csPCa. PRIMARY scoring had a sensitivity of 77% and specificity of 58%, with a positive predictive value of 83%. A moderate correlation was observed between PRIMARY scores and ISUP GG (Rho = 0.54, p < 0.001). In contrast, the PIRADS score displayed a sensitivity and specificity of 86% and 25% respectively, with a positive predictive value of 68%. No substantial correlation was found between PIRADS and ISUP GG. Statistical analysis revealed a significant correlation between PRIMARY and ISUP GG (p < 0.001), but not between PIRADS and ISUP GG (p = 0.281). Comparatively, PRIMARY scoring was significantly more reliable than PIRADS scoring in identifying csPCa. CONCLUSION: [68 Ga]Ga-PSMA-11 PET/CT imaging is promising for distinguishing high-risk prostate cancer patients from those apt for active surveillance, potentially aiding in the identification of csPCa.

Benign Bone Cyst Mimicking Bone Metastasis Demonstrated on 68Ga-FAPI.

ABSTRACT: A 59-year-old woman with lobular breast cancer was referred to nuclear medicine department for a 68Ga-FAPI PET/CT study after completion of treatment to rule out the possibility of metastatic disease. It revealed a lytic lesion showing increased FAPI accumulation in the right acetabulum, highly suspicious for bone metastasis. In comparison to an initial 18F-FDG PET/CT study done 2 years before, the lytic lesion showing no FDG uptake in the right acetabulum remained unchanged, and the findings were consistent with bone cyst. This case highlighted that benign bone cyst may demonstrate increased 68Ga-FAPI uptake mimicking bone metastasis on 68Ga-FAPI PET/CT.

Coincidence of follicular lymphoma and hurtle cell thyroid carcinoma in a patient at presentation: which one is the source of bone metastasis? Case report and review of the literature.

Thyroid incidentaloma is defined as a new identified thyroid lesion occasionally detected during imaging studies. Incidence of thyroid incidentalomas is relatively rare in patients with lymphoma. Because of high rate of malignancy, these lesions with high intensity focal 18 FDG uptake detected on positron emission tomography with computed tomography (PET/CT) should undergo to biopsy regardless of size.

Unicentric mixed variant Castleman disease associated with Hashimoto disease: the role of PET/CT in staging and evaluating response to the treatment.

Castleman disease (CD) is a rare atypical lymphoproliferative disease, pathologically classified as hyaline vascular, plasma cell type and mixed type variant. The underlying cause of CD is unknown, however several theories including autoimmunity have been proposed. We describe a patient diagnosed with unicentric mixed variant CD and Hashimoto thyroiditis, concurrently. She was staged with fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) and the disease was localized to the mediastinum. After 6 cycles of chemotherapy consisting of vincristine and prednisone, the mediastinal lymph nodes regressed, but did not disappear from the CT scan. However, FDG-PET/CT showed complete metabolic response. Although the role of FDG-PET/CT in staging and evaluation of treatment response is controversial, this case shows that PET/CT can be effective and even better for staging and response evaluation. This case is also unique as there no case of CD in association with Hashimoto thyroiditis has been reported previously. However, the possibility of a coincidental association must be raised, especially when the high prevalence of Hashimoto thyroiditis is considered.

Significance of increased scrotal Tc-99m MDP uptake in patients with prostate cancer.

OBJECTIVE: We observed an unusually increased scrotal uptake as an interesting finding in some patients with prostate cancer who were scanned for any possible metastatic disease. This study was designed to investigate the significance of this incidental finding in the technetium-99m methylene diphosphonate scintigraphies. METHODS: The study population consisted of 104 patients with biopsy-proven prostate cancer (group I), 55 male patients with other cancers (group II), 30 male patients with nonmalignant diseases (group III) and finally 15 patients with benign prostate hypertrophy (group IV). The square-shaped regions of interest are placed centrally on the scrotum and then on the lateral femoral soft tissue. Then the simple ratios of the scrotal and femoral soft tissue mean counts (S/Bg) were calculated. The statistical significance of differences among the groups in terms of scrotal uptake was determined. RESULTS: Group I showed increased scrotal uptake relative to the other groups. The mean uptake ratios (S/Bg±standard deviation) were 3.49±1.42 in group I, 2.89±0.70 in group II, 2.87±0.75 in group III, and 2.91±0.60 in group IV. This ratio was significantly higher in patients with prostate cancer than the normal group (P=0.024), the group with benign prostate hypertrophy (P=0.004), and the patients with other cancers (P=0.004). CONCLUSION: Our results showed that technetium-99m methylene diphosphonate bone scintigraphy, as a routine for detecting metastatic disease or performed for other purposes, could give clues for a hidden prostate cancer. Then, in elderly male patients, we strongly recommend that it is wise to keep one's eye on scrotal activity when bone scans are read and where there is any doubt, take appropriate regions of interest to make quantitative evaluations.

The anti-inflammatory effect of low-level laser therapy on experimentally induced inflammation of rabbit temporomandibular joint retrodiscal tissues.

AIMS: To investigate the effect of low-level laser therapy (LLLT) on experimentally induced inflammation in retrodiscal tissues of the rabbit temporo?mandibular joint (TMJ) using scintigraphic imaging. METHODS: Eleven male New Zealand rabbits were included in this study. Six randomly selected rabbits were imaged to provide normal joint images (normal group) before the initiation of the experiment. A 5% formalin solution was locally injected into both right and left TMJs of all rabbits. Subsequently, Ga-Al-As laser (wavelength: 815 nm; energy density: 12 J/cm2; output power: 250 mW) was applied for 48 seconds. The treatment was performed six times for 2 weeks to the left TMJ of all rabbits. The right TMJs of the rabbits were used as the control (nontreated) TMJ group, while left TMJs were used as the treated TMJ group. Static images of TMJ were taken at 24 hours, 7 days, and 14 days after the beginning of the treatment. The images of all TMJs were taken in the posteroanterior direction with the rabbit under sedation and its mouth open. The Mann-Whitney U test was used to compare group differences, and intragroup differences were determined by the Friedman test and Wilcoxon sign test. RESULTS: Significant differences were found between normal and both the control and treated TMJ groups. A reduction of inflammation in both treated and control TMJ groups was obtained, but there was no statistically significant difference between the groups. CONCLUSION: Under the conditions used in this study, quantitative scintigraphic measurements of TMJ inflammation of the treated TMJ group decreased but did not differ significantly from those of the control TMJ group.

Intravascular radiation therapy with a Re-188 liquid-filled balloon in patients with in-stent restenosis.

OBJECTIVE: The aim of this study was to evaluate the feasibility and safety of intravascular radiation therapy (IVRT) using Re-188 filled balloon system in patients with in-stent stenosis. METHODS: A total of 39 patients with in-stent restenosis were enrolled as the IVRT (22 patients) and control groups (17 patients) of this study after a successful coronary angioplasty. For irradiation the angioplasty balloon was replaced by a noncompliant balloon of the same diameter but 10 mm longer in length with a proximal and distal radio-opaque marker to deliver the dose of 18 Gy at 0.5 mm depth from the surface of the balloon into the vessel wall. Angiographic follow-up was performed after 6 months. RESULTS: The length of the irradiated segment was between 9.14 and 22 mm and the diameter between 2.5 and 3 mm. In the IVRT group, two patients who did not receive antiplatelet therapy had myocardial infarction. Four patients who presented with stable angina earlier also had angiographically documented in-stent occlusion (two patients) and edge stenosis (two patients) of the target lesion and received angioplasty (18.1%). In the control group, three patients with recurrent angina and four asymptomatic patients had documented in-stent occlusion angiographically at 6 months and these seven patients underwent target lesion revascularization (41.2%). The overall restenosis rate in the IVRT and control groups were 23.91 and 39.86%, respectively (P=0.013). No complications were documented, except anginal pain and ST segment changes. CONCLUSION: Our results indicated that the Re-188 liquid-filled balloon is feasible, safe, and effective in patients with in-stent restenosis.

Treatment of iodine-negative thyroglobulin-positive thyroid cancer: differences in outcome in patients with macrometastases and patients with micrometastases.

PURPOSE: During the follow-up of patients with well-differentiated thyroid carcinoma, some patients have elevated serum thyroglobulin (Tg) levels without any evidence of radioiodine accumulation on diagnostic whole-body scan (d-WBS). The treatment strategy in these patients is considered a clinical dilemma, with some groups recommending blind use of high-dose radioiodine therapy. The aim of this study was to evaluate whether or not high doses of radioiodine have beneficial effects in these patients. METHODS: Twenty-seven patients were included in the study. All patients had negative d-WBS and elevated levels of Tg. All received high doses of radioiodine. The mean follow-up period was 6.3+/-5.8 years. There were 11 patients with macrometastases and 16 with micrometastases. RESULTS: Post-treatment WBS revealed radioiodine accumulation in 19 of 24 (79%) patients. Serum Tg levels were decreased in 8 of 16 (50%) patients. Among patients with micrometastases, five out of seven (71%) demonstrated a decrease in serum Tg levels. Among patients with macrometastases, three out of nine (33%) demonstrated a decrease in Tg values and three (33%) have died due to metastatic thyroid cancer. CONCLUSION: Radioiodine treatment may have a beneficial therapeutic effect in patients who have elevated levels of serum Tg and negative d-WBS. This is especially true in those patients with micrometastases; in patients with macrometastases, a beneficial effect of this approach may be observed less frequently.