18F-FDG PET/CT texture analysis of anthracotic lymph nodes detected with EBUS and comparison with cytological findings.

OBJECTIVE: Lymph node metastasis is the most important factor both in the selection of treatment since many alternatives have been created in recent years, and in the evaluation of prognosis in lung cancer. The most unpredictable cause of lymph node false positivity in fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is anthracosis. The aim of this study is to compare 18F-FDG PET/CT texture information of anthracotic (ALN) and metastatic (MLN) lymph nodes, after re-evaluation of the cytological samples obtained from anthracotic lymph nodes by EBUS-TBNA. SUBJECTS AND METHODS: Ninety nine patients, 78 of whom had primary lung cancer were included in the study. Two hundred and three lymph nodes from 99 patients sampled by EBUS-TBNA and diagnosed cytologically as ALN or MLN were evaluated retrospectively. All ALN were classified as grades 1, 2 and 3 cytologically. Volume of interest (VOI) of 203 lymph nodes was re-drawn and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) values were recorded. RESULTS: There was a statistically significant difference in MTV and TLG values in MLN and all ALN grades. However, only grade 1-2 ALNs could be differentiated from MLNs with SUVmax, and no statistically significant difference was found in grade 3 ALN and MLN. Metabolic tumor volume and TLG values over 4.10cm3 and 26.57 showed 60% and 59% sensitivity and 83% and 94 specificity respectively for the identification of MLN. CONCLUSION: The contribution of MTV and TLG values of 18F-FDG PET/CT to the differential diagnosis of ALN is much more valuable than SUVmax values, especially for grade 3 anthracosis. It was thought that cytological reporting of only grade 3 ALN could make a better contribution to the 18F-FDG PET/CT evaluation analysis.

The use of focused, radioguided parathyroidectomy in geriatric patients with a history of thyroid surgery.

OBJECTIVE: Geriatric patients are often reluctant to undergo parathyroid surgery under general anesthesia because of the major comorbidities. The use of minimally invasive techniques for parathyroid lesions under local anesthesia have been published. Radioguided lesion localization has been known to decrease operative time and reduce the occurrence of positive margins in breast cancer surgery. We hypothesize that it could also be effectively used in focused parathyroid surgery in geriatric patients with in history of thyroid surgery. MATERIALS AND METHODS: Our study group consists of geriatric patients with a history of thyroid surgery who underwent focused parathyroid surgery between February 2017 and October 2019. Group-1 included 18 patients who had parathyroidectomy under radioguidance. Group-2, 22 patients who had surgery without it. Patient demographics, operative time, number of frozen sections and length of hospital stay were analyzed. RESULTS: Analyzed data were similar between groups. The mean age of the patients was 72.56±12.65 years (range: 65-88). The operative times for group-1 and group-2, were 65.42±7.78 and 74.63±15.98 minutes, respectively (P=0.002). All patients were discharged uneventfully on postoperative day-2. CONCLUSION: Radioguidance parathyroidectomy positively affected the operative time and also decreased the need for additional frozen section.

Fluorescence-guided extended pelvic lymphadenectomy during robotic radical prostatectomy.

We evaluated and described the impact of prostatic indocyanine green (ICG) injection on extended pelvic lymph node (LN) dissection (ePLND) in robotic-assisted radical prostatectomy (RARP). Between January 2019 and December 2021, we included consecutive 50 PCa patients who underwent ePLND during RARP with (n = 25) or without (n = 25) prostatic ICG injection. ICG injection was performed during abdominal port placement and robot docking. Pelvic LNs reflecting green color were initially excised and then the template was completed. The outcomes of two groups were compared. Overall, nine (36%) and five (20%) of the patients had metastatic LN involvement in the ICG and non-ICG groups, respectively. Of the 509 dissected LNs in the ICG group, 122 (23.9%) were fluorescence active. 20 LNs (3.9%) were metastatic in this group, 9 (45%) of which were ICG+. 408 LNs were resected on the non-ICG group with 8(1.9%) being metastatic. Eight (88.9%) of nine pN+ patients were florescent positive in the ICG group. Out of six patients with pN+ disease, Ga68 PSMA-PET/CT detected positive LNs preoperatively. In addition to preoperative Ga68 PSMA-PET/CT investigation, ICG-guided ePLND might increase identification and removal of metastatic LNs duirng RARP. Improvements in staging and oncologic outcomes may also be seen in intermediate- and high-risk patients.

Posttherapeutic Critical Organ Dosimetry of Extensive 177Lu-PSMA Inhibitor Therapy With Metastatic Castration-Resistant Prostate Cancer: One Center Results.

PURPOSE: Lu-PSMA inhibitor peptide receptor radioligand therapy (RLT) is playing an increasing role in metastatic castration-resistant prostate cancer. We aimed to estimate the absorbed radiation doses for critical organs (eg, kidneys, parotid glands, submandibular glands, and lacrimal glands) of patients treated with 4 to 6 cycles by Lu-PSMA inhibitor RLT, retrospectively, and to evaluate the findings extensively in order to determine the critical organ radiation-absorbed limitations and the number of prospective RLT. MATERIALS AND METHODS: A total of 51 cycles Lu-PSMA inhibitor RLT in 10 patients was analyzed. Therapies have been applied in 4 to 6 cycles with 8 to 10 weeks' intervals. Dosimetric estimates of kidneys, parotid glands, submandibular glands, and lacrimal glands have been calculated based on MIRD scheme pamphlet no. 16. Regions of interest were drawn with GE Xeleris Functional Imaging Workstation. OLINDA/EXM 1.1 simulation software was used to calculate radiation-absorbed doses. RESULTS: Mean radiation-absorbed doses were 0.70 ± 0.24 Gy/GBq for kidneys, 1.34 ± 0.78 Gy/GBq for parotid glands, 0.94 ± 0.45 Gy/GBq for submandibular glands, and 2.28 ± 1.29 Gy/GBq for lacrimal glands. CONCLUSIONS: Due to the critical target organ risks and the optimal therapy doses, patient-specific dosimetry is a deterministic factor in radionuclide therapy. Even when the absorbed kidney doses were above the ICRP critical dose limits in patients who had 4 to 6 cycles of therapy, mortality due to nephrotoxicity has not been observed. Mild increased tolerated radiation dose is acceptable for the patient groups with very low survival rate.