The relation between staging fluorine-18 fluorodeoxyglucose positron emission tomog- raphy/computed tomography metabolic parameters and tumor necrosis rate in pediatric osteosarcoma patients

Background/aim: The aim of this study was to investigate the contribution of fluorine-18 (F-18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in staging of pediatric osteosarcoma patients and also to evaluate the ability of metabolic parameters from the primary tumor to predict tumor necrosis rate (TNR). Material and methods: F-18 FDG-PET/CT imaging was performed in staging 37 pediatric osteosarcoma patients. The metabolic pa- rameters SUVmax (maximum standardised uptake value), MTV (metabolic tumour volume), and TLG (total lesion glycolysis) were measured from the primary tumor. TNR level of the primary tumor was histopathologically measured after standard neoadjuvant chemotherapy treatment. The contribution of F-18 FDG-PET/CT to staging of pediatric osteosarcoma patients and the accuracy of metabolic parameters of the primary tumor to predict TNR were analized by regression analysis. Results: MTV and TLG of the primary tumor were found to efficiently predict histopathologic TNR, whereas SUVmax was not (P = 0.012, P = 0.027, P = 0.25, respectively). Also 5 of 12 patients (41.6%) who were initially defined as localised osteosarcoma were upstaged in consequence of staging F-18 FDG-PET/CT findings. Conclusion: F-18 FDG-PET/CT staging in pediatric osteosarcoma patients can effectively distinguish metastatic-localised disease. MTV and TLG values are important parameters, which can efficiently be used to predict TNR.

The Added-value of Staging 18F-FDG PET/CT in the Prediction of Overall Survival in the Patients with Bladder Cancer.

Objectives: This retrospective study aimed to evaluate the prognostic importance of 18F-fluorodeoxyglucose (18F-FDG)-positive pelvic lymph nodes (LNs) and extra-pelvic disease on staging 18F-FDG positron emission tomography/computed tomography (PET/CT) in patients with bladder cancer. Methods: Bladder cancer patients who underwent staging 18F-FDG PET/CT were included in the study. Histopathologic features of tumors, therapy histories, presence of distinguishable tumors on CT and PET images, sizes and maximum standardized uptake value (SUVmax) of primary tumors, total numbers, sizes, and SUVmax of 18F-FDG-positive pelvic and extra-pelvic LNs, and total numbers and SUVmax of distant metastases (M1a/1b) were recorded. Patients were followed up until death or the last medical visit. Factors predicting overall survival were determined using Cox regression analysis. Results: Fifty-five patients [median age: 70 (53-84), 48 (87.3%) male, 7 (12.7%) female] with bladder cancer were included in this study. Twenty-nine (52.7%) patients had 18F-FDG positive pelvic LNs, while 24 (43.7%) patients had 18F-FDG positive extra-pelvic disease. Patients with 18F-FDGpositive pelvic LNs had a higher rate of extra-pelvic disease (p=0.003). The median follow-up duration was 13.5 months. The median overall survival was 16.3 months [95% confidence interval (CI) 8.9-23.7]. The primary tumor distinguishability on PET (p=0.011) and CT (p=0.009) images, the presence of 18F-FDG-positive pelvic LNs (p<0.001) and 18F-FDG-positive extra-pelvic disease/distant metastases (M1a/M1b) (p<0.001), and the number of distant metastases (p=0.034) were associated with mortality. The 18F-FDG-positive extra-pelvic disease/distant metastases [p=0.029, odds ratio: 4.15 (95% CI 1.16-14.86)] was found to be an independent predictor of mortality in patients with bladder cancer. Conclusion: The presence of 18F-FDG-positive extra-pelvic disease in pretreatment 18F-FDG PET/CT is an important prognostic factor in bladder cancer patients.

Primary tumor heterogeneity on pre-treatment [68Ga]Ga-PSMA PET/CT for the prediction of biochemical recurrence in prostate cancer.

PURPOSE: The aim of this study is to research the value of the texture analysis of primary tumors in pre-treatment [68Ga]Ga-PSMA PET in the prediction of the development of biochemical recurrence (BCR) in prostate cancer patients who underwent definitive therapies. METHODS: 51 patients with prostate adenocarcinoma who had a pre-treatment [68Ga]Ga-PSMA-11 PET/CT and underwent definitive radiotherapy (RT) or radical prostatectomy (RP) were included in the study. Demographics, clinicopathologic features, the presence of BCR, and the last follow-up date of patients were recorded. Textural and conventional PET parameters (maximum standardized uptake value (SUVmax), total lesion-PSMA (TL-PSMA), and PSMA-tumor volume (PSMA-TV)) were obtained from PET/CT images using LifeX program. Parameters were grouped using the Youden index in ROC analysis. Factors predicting the BCR were determined using Cox regression analyses. RESULTS: 29 (56.9%) patients have received primary curative RT, while the remaining 22 (43.1%) patients have undergone RP. 5 (22.7%) patients with RP and 3 (10.3%) patients with curative RT have developed BCR during the follow-up. INTENSITY-BASED-minimum grey level (P=.050), GLCM-sum variance (P=.019), and GLCM-cluster prominence (P=.050) were associated with BCR in univariate analysis. INTENSITY-BASED-minimum grey level (P=.009) and GLCM-sum variance (P=.004) were found as independent predictors of BCR in the multivariate analysis. CONCLUSION: Tumor heterogeneity on pre-treatment [68Ga]Ga-PSMA PET is associated with a high risk of BCR in PCa patients who underwent definitive therapies.

Prognostic value of primary tumor and lymph node volumetric metabolic parameters at pre-treatment F-18 FDG PET/CT in nasopharyngeal carcinoma.

BACKGROUND: The aim of this study was to evaluate the prognostic significance of volumetric metabolic parameters of pre-treatment PET/CT along with clinical characteristics in patients with non-metastatic nasopharyngeal carcinoma. MATERIAL AND METHODS: Seventy-nine patients with nasopharyngeal carcinoma underwent F18- FDG PET/CT for pretreatment evaluation and included in this study. The patient features (patient age, tumor histopathology, T and N stage, size of primary tumor and the largest cervical lymph node) and PET parameters were analyzed: maximum, mean and peak standardized uptake values (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumor and largest cervical lymph node. After treatment, patients were evaluated for disease progression and mortality. Survival analysis for progression-free survival (PFS) and over-all survival (OS) was performed with Kaplan-Meier method using PET findings and clinical characteristics. RESULTS: The median follow-up duration was 29.7 months (range 3-125 months). Among clinical characteristics, no parameters had significance association for PFS. Primary tumor-MTV and cervical lymph node-MTV were independent prognostic factors for PFS (p = 0.025 and p = 0.004, respectively).Patients with primary tumor-MTV >19.4 and patients with lymph node-MTV>3.4 had shorter PFS. For OS, age and the size of the lymph node were independent prognostic factor (p = 0.031 and p = 0.029).Patients with age over 54 years and patients with lymph node size >1 cm were associated with decreased OS. CONCLUSION: Primary tumor-MTV and lymph node-MTV on pre-treatment PET/CT are significant prognostic factors for long-term PFS in non-metastatic nasopharyngeal carcinoma. We consider that measuring MTV as volume-based metabolic parameter on pretreatment PET/CT may contribute decision of treatment intensity and individualized risk stratification and may improve long-term PFS. Additionally, age and the size of lymph node are independent prognostic factors for mortality.

Sentinel Lymph Node Detection in Contralateral Axilla at Initial Presentation of a Breast Cancer Patient: Case Report.

The main basin for breast lymphatic drainage is ipsilateral axilla. However, extra-axillary drainage may be seen in some patients. The most common extra-axillary site is internal mammary chain, while contralateral axillary drainage is an extremely rare situation in previously untreated patients. We describe a case of untreated right breast retroareolar carcinoma with contralateral axillary drainage detected on preoperative lymphoscintigraphy. Contralateral axillary dissection was performed based on the result of frozen section examination of the sentinel lymph node (SLN) which turned out to burden micrometastasis. Postoperative histopathological examination revealed invasive ductal carcinoma metastasis in 17 out of 22 lymph nodes from the ipsilateral axillary dissection, whereas 14 lymph nodes from contralateral axillary dissection other than the SLN were nonmetastatic. In our opinion, determination of contralateral axillary metastasis in primary staging process had a major contribution to the management of the patient.

Gall bladder visualization in lymphoscintigraphy.

BACKGROUND: The aim of this study was to evaluate gall bladder visualization in lymphoscintigraphy of extremities. METHODS AND RESULTS: Thirteen patients who had prediagnoses of lymphedema and were referred for lower extremity lymphoscintigraphy to our department were retrospectively evaluated. Lower extremity lymphoscintigraphy with Tc-99m sulfur colloid was performed on the patients, and planar images of the lower extremity and abdominal region were taken in early phase and late phase (at the 24th hour) routinely. Lymphoscintigraphy results of eight patients were normal regarding lymphatic flow or lymph nodes; however, additional pathologic tracer accumulations in gall bladder were observed, which disappeared at 24th hour images in three patients. Five patients had various pathologies regarding lymph flow or lymph nodes. However, there were no patients with gall bladder activity except those three patients who had casual anamnesis of fasting prior to the exam. CONCLUSION: The fasting state of the patients might be the cause of gall bladder visualization during the lymphoscintigraphy of the extremities with sulfur colloid.