Value of Dynamic 18F-FDG PET/CT in Predicting the Success of Neoadjuvant Chemotherapy in Patients with Locally Advanced Breast Cancer: A Prospective Study.

Objectives: This prospective study was planned to compare the predictive value of dynamic 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in locally advanced breast cancer patients (LABC) receiving neoadjuvant chemotherapy (NAC). Methods: Twenty seven patients with LABC [median age: 47, (26-66)] underwent a dynamic 18F-FDG PET study at baseline, and after 2-3 cycles of (NAC) were included (interim). Maximum standardized uptake value (SUVmax) values and SUV ratios for the 2nd, 5th, 10th, and 30th minutes and dynamic curve slope (SL) values and SL ratios were measured using 18F-FDG dynamic data. In addition, the values of SUVmean (2minSUVmean), SULpeak (2minSULpeak), metabolic volume (2minVol), and total lesion glycolysis (2minTLG) were measured for the first 2 min. Percent changes between baseline and interim studies were calculated and compared with the pathological results as the pathological complete response (PCR) or the pathological non-complete response (non-PCR). Receiver operating characteristic curves were obtained to calculate the area under the curve to predict PCR. Optimal threshold values were calculated to discriminate between PCR and non-PCR groups. Results: Baseline study SUV 30 (p=0.044), SUV 30/2 (p=0.041), SUV 30/5 (p=0.049), SUV 30/10 (p=0.021), SL 30/2 (p=0.029) and SL 30/5 (p=0.027) values were statistically significant different between PCR and non-PCR groups. The percentage changes of 2minVol between PCR and non-PCR groups were statistically significant. For the threshold value of -67.6% change in 2minVol, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.2%, 77.8%, 63.6%, 93.3%, and 80.7%, respectively (area under the curve: 0.826, p=0.009). Conclusion: Semiquantitative parameters for dynamic 18F-FDG PET can predict PCR. % changes in 2minVol can identify non-responding patients better than other parameters.

Necrosis onstaging 18F FDG PET/CT is associated with worse progression-free survival in patients with stage IIIB non-small cell lung cancer.

Objective: The presence of pathological necrosis in the tumor is known to be a factor indicating worse survival. Our study defined necrosis in staging 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with stage IIIB non-small-cell lung cancer (NSCLC) to investigate whether this is a poor prognostic marker. Methodology: A total of 77 patients with NSCLC were evaluated. To evaluate necrosis on 18F FDG PET/CT, we drew a region of interest (ROI) in the area showing visually very low/or no FDG uptake on PET and PET/CT fusion images. If SUVmax was less than blood pool SUVmax and showed significantly less attenuation [10 to 30 Hounsfield units (HUs)] than surrounding tissue on low-dose correlative CT with non-intravenous contrast, we defined it as necrotic (PETNECROSIS). We evaluated the relationship of SUVmax, tumor size, and PETNECROSIS with progression-free survival (PFS) using a Cox proportional hazard regression model. Results: A PFS analysis was performed on 16 patients treated with standard chemoradiotherapy (CRT) regimen. Tumor size ≤42 mm versus >42 mm (P = 0.044, HR: 6.103, 95 CI%: 1.053-35.358) and PETNECROSIS presence/absence (P = 0.027, HR: 6.719, 95 CI%: 1.245-36.264) were independent predictors for PFS. Patients with tumor size ≤42 mm and PETNECROSIS absence were associated with higher 1-year PFS rate than patients with tumor size >42 mm and PETNECROSIS presence (86% vs. 63.5% P = 0.005 and 87.5% vs. 29%, P = 0.001, respectively). Conclusion: PETNECROSIS is helpful to distinguish the patients who would suffer worse survival in stage IIIB NSCLC.

Necrosis on pre-radiotherapy 18F-FDG PET/CT is a predictor for complete metabolic response in patients with non-small cell lung cancer.

ABSTRACT: To investigate necrosis on pre-radiotherapy (RT) 18F-FDG PET/CT (PETNECROSIS) as a predictor of complete metabolic response (CMR) in patients with non-small cell lung cancer (NSCLC).We evaluated patients with inoperable stage I-III NSCLC who underwent pre- and post-radiotherapy 18F-FDG PET/CT. The relationship between CMR and PETNECROSIS, SUVmax, gross tumor volume calculated with 18F-FDG PET/CT (GTVPET-CT), tumor size, histology, metabolic tumor volume (MTV), and RT dose was assessed using logistic regression analysis. To evaluate necrosis on 18F FDG PET/CT, we drew a region of interest (ROI) in the area showing visually very low/or no fluorodeoxyglucose (FDG) uptake on PET images. If the SUVmax was lower than the blood pool SUVmax and showed significantly lower attenuation (10-30 Hounsfield units [HU]) from the surrounding tissue on non-intravenous contrast-enhanced low-dose correlative CT, we defined it as necrotic (PETNECROSIS).Fifty-three patients were included in this study. The mean age was 68.1 ±â€Š9.8 years. Twenty-one patients had adenocarcinoma, and 32 had squamous cell carcinoma. All parameters were independent of histologic status. Multivariate logistic regression analysis showed that SUVmax ≤11.6 vs >11.6, (P = .003; OR, 7.670, 95CI%: 2.013-29.231) and PETNECROSIS absence/presence were independent predictors for CMR (P = .028, OR: 6.704, 95CI% 1.214-30.394).The necrosis on 18F FDG PET/CT and SUVmax > 11.6 could be an imaging marker for the complete metabolic response after definitive chemoradiotherapy or definitive RT alone in patients with NSCLC.

A comparison study of dual-energy spectral CT and 18F-FDG PET/CT in primary tumors and lymph nodes of lung cancer.

PURPOSE: We aimed to investigate whether there is a correlation between dual-energy spectral computed tomography (DESCT) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) parameters in primary tumor and metastatic lymph nodes in patients with newly diagnosed lung cancer. METHODS: Primary tumor and metastatic lymph nodes of 68 patients diagnosed with lung cancer were evaluated retrospectively with 18F-FDG PET/CT and DESCT imaging. The histologic subtypes were adenocarcinoma (n=29), squamous cell carcinoma (SCC) (n=26), small cell lung cancer (SCLC) (n=11), and large cell neuroendocrine cancer (LCNEC) (n=2). In terms of PET parameters, SUVmax, SUVmean, SULmax, SULmean, SULpeak, and normalized SUL values were obtained for primary tumors and metastatic lymph nodes. In terms of DESCT parameters, maximum and mean iodine content (IC), normalized IC values, iodine enhancement (IE) and normalized IE values were calculated. RESULTS: We found no correlation between DESCT and 18F-FDG PET/CT parameters in primary tumors and metastatic lymph nodes. In addition, no correlation was found in the analysis performed in any of the histologic subgroups. In patients with a primary tumor <3 cm, there was a moderate negative correlation between the parameters SUVmax-ICmax (r= -0.456, p = 0.043), SUVmean-ICmax (r= -0.464, p = 0.039) SULmean-ICmax (r= -0.497, p = 0.026), SUVmax-ICmean (r= -0.527, p = 0.020), SULmean-ICmean (r= -0.499, p = 0.025), and SULpeak-ICmean (r= -0.488, p = 0.029). CONCLUSION: We consider that DESCT and 18F-FDG PET/CT indicate different characteristics of the tumors and should not supersede each other.

PET-CT and MR Imaging in the Management of Axillary Nodes in Early Stage Breast Cancer.

OBJECTIVE: To discriminate between malignant or benign axillary lymph nodes in breast cancer using MRI, PET-CT, and sentinel lymph node biopsy. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of General Surgery, Recep Tayyip Erdogan University School of Medicine, from January 2014 to March 2019. METHODOLOGY: Sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) was carried out on 102 patients, who had locally advanced cases and had not previously received neoadjuvant therapy. Axillary lymph nodes pathology results were evaluated and compared with PET-CT and MRI findings. RESULTS: PET-CT specificity was 93.18%, MRI specificity was 93.75%, and combined PET-CT and MRI specificity was 97.67%. PET-CT sensitivity was 81.03%, MRI sensitivity was 68.57%, and combined PET-CT and MRI sensitivity was 83.05%. For detecting the presence of axillary lymph node metastasis, there was a good correlation between histopathological results and the combined evaluation with PET-CT and MRI (kappa: 0.785, p <0.001). In combined PET-CT and MRI, short diamater mean values of lymph nodes in 10 patients, which could not detect lymph node metastases, were determined to be 5.2 ±0.9 mm. CONCLUSION: Combining PET-CT and MRI is superior to PET-CT or MRI imaging alone in distinguishing benign and malignant axillary lymph node; and contributes to deciding the approach to axillary lymph node surgery. Lymph node size is also important for this imaging method to determine benign and malignant nodes correctly. Key Words: Breast cancer, PET-CT, MRI, Sentinel lymph node biopsy, Axilla.

Comparison of clinical and PET-derived prognostic factors in patients with non-Hodgkin lymphoma: a special emphasis on bone marrow involvement.

OBJECTIVE: In patients with non-Hodgkin lymphoma (NHL), we investigated F FDG PET/computed tomography (CT) parameters, clinical findings, laboratory parameters, and bone marrow involvement (BMI) status for predictive methods in progression-free survival (PFS) and overall survival (OS), and whether F FDG PET/CT could take the place of bone marrow biopsy (BMB). METHODS: The performance of F FDG PET/CT (BMPET) was evaluated. The prognostic value of maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), stage, international prognostic index (IPI) score, IPI risk, lactate dehydrogenase (LDH), B2 microglobulin, Ki67 proliferation index, and the presence of BMI was evaluated for OS and PFS. Kaplan-Meier curves were drawn for each designated cutoff value, and 5-year PFS and 7-year OS were evaluated using log-rank analysis. RESULTS: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of BMPET and BMB to identify BMI were 69, 100, 86.1, 80, 100%, and 81.6, 100, 92.5, 89, 100%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of BMPET in patients with Ki67- proliferation index >25% were all 100%. BMPET, IPI risk, MTV, and LDH were found to be independent prognostic predictors for PFS, whereas BMPET, SUVmax, and MTV for OS. Five-year PFS analysis estimated as follows: BMPET (+) = 22%, BMPET (-) = 80%, LDH ≤ 437 (U/L) = 86%, LDH > 437 (U/L) = 51%, MTV ≤ 56 (cm) = 87%, MTV > 56 (cm) = 49%, low IPI risk = 87%, intermediate IPI risk = 69%, high IPI risk = 25%. Seven-year OS analysis was found as: SUVmax ≤ 17.6 = 80%, SUVmax > 17.6 = 48%, MTV ≤ 56 (cm) = 84.4%, MTV > 56 (cm) = 45.8%, BMPET (-) = 72.5%, BMPET (+) = 42%. CONCLUSION: In the Ki-67 proliferation index > 25% group, F FDG PET/CT was able to differentiate BMI independently from NHL subgroups. We recommend using this method with large patient groups. MTV and BMPET were independent prognostic indicators for OS and PFS and may help to determine high-risk patients.

FDG PET/CT in Peritoneal Metastasis From Prostate Cancer.

Prostate cancer is one of the leading causes of cancer death in men. The prognosis in prostate cancer is greatly worsened by the presence of metastases, which are most commonly found in bone, lung, liver, and brain. The peritoneum is an extremely uncommon metastatic site for prostate cancer, even in autopsy series. We present a case of FDG PET/CT demonstration of peritoneal metastasis from prostate cancer.