Baseline Metabolic Tumor Volume and Total Lesion Glycolysis Are Associated With Survival Outcomes in Patients With Locally Advanced Pancreatic Cancer Receiving Stereotactic Body Radiation Therapy

Abstract

Purpose Although previous studies have demonstrated the prognostic value of positron emission tomography (PET) parameters in other malignancies, the role of PET in pancreatic cancer has yet to be well established. We analyzed the prognostic utility of PET for patients with locally advanced pancreatic cancer (LAPC) undergoing fractionated stereotactic body radiation therapy (SBRT). Materials and Methods Thirty-two patients with LAPC in a prospective clinical trial received up to 3 doses of gemcitabine, followed by 33 Gy in 5 fractions of 6.6 Gy, using SBRT. All patients received a baseline PET scan prior to SBRT (pre-SBRT PET). Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum and peak standardized uptake values (SUVmax and SUVpeak) on pre-SBRT PET scans were calculated using custom-designed software. Disease was measured at a threshold based on the liver SUV, using the equation Livermean + [2 × Liversd]. Median values of PET parameters were used as cutoffs when assessing their prognostic potential through Cox regression analyses. Results Of the 32 patients, the majority were male (n = 19, 59%), 65 years or older (n = 21, 66%), and had tumors located in the pancreatic head (n = 27, 84%). Twenty-seven patients (84%) received induction gemcitabine prior to SBRT. Median overall survival for the entire cohort was 18.8months (95% confidence interval [CI], 15.7–22.0). An MTV of 26.8 cm3 or greater (hazard ratio [HR] 4.46, 95% CI 1.64–5.88, P<.003) and TLG of 70.9 or greater (HR3.08,95%CI 1.18–8.02,P<.021) on pre-SBRT PET scan were associated with inferior overall survival on univariate analysis. Both pre-SBRT MTV (HR 5.13, 95% CI 1.19–22.21, P = .029) and TLG (HR 3.34, 95% CI 1.07–10.48, P = .038) remained independently associated with overall survival in separate multivariate analyses. Conclusions Pre-SBRT MTV and TLG are potential predictive factors for overall survival in patients with LAPC and may assist in tailoring therapy.

Total 18F-FDG PET/CT Metabolic Tumor Volume Is Associated With Postoperative Biochemical Response in Patients With Metastatic Pheochromocytomas and Paragangliomas

“…15,16 Given the ability of 18F-FDG PET/CT to identify metastatic disease, there is a potential for quantification of disease burden for prognosis and treatment response by measuring the whole body metabolic tumor volume (MTV) as defined by 18F-FDG uptake, and total lesion glycolysis (TLG), which is the product of the mean standardized uptake value (SUV) and the volume of the tumor. 17,18 Measurement of whole body MTV and TLG has been found to be a potentially valuable prognostic parameter and has been recently utilized to predict the prognosis of various cancers, such as esophageal cancer, 19 multiple myeloma, 20 and small cell lung cancer, 21 and has been utilized to predict treatment response in pancreatic cancer 22,23 and non-small cell lung cancer. 24 Furthermore, automated and semiautomated methods with various thresholds based on the percentage of the SUV max have been developed to decrease inter-and intraobserver variation in tumor volume delineation, which allows data to be more accurate and generalizable.…”

Changes in Total Lesion Glycolysis Evaluated by Repeated F-18 FDG PET/CT as Prognostic Factor in Locally Advanced Esophageal Cancer Patients Treated with Preoperative Chemoradiotherapy

“…However, the current study showed the prognostic roles of OS and RFS in MTV only in univariate analysis. It is well known that pretreatment MTV and TLG are potent prognostic factors in various cancers [29,30,31]. Nevertheless, conflicting results regarding the prognostic role of sequential F-18 FDG PET/CT still exist in LAEC patients treated with preoperative CRT.…”

Volumetric Parameters Changes of Sequential 18F-FDG PET/CT for Early Prediction of Recurrence and Death in Patients With Locally Advanced Rectal Cancer Treated With Preoperative Chemoradiotherapy

“…[27][28][29] However, conflicting results regarding prognostic role of sequential 18 F-FDG PET/CT still exist in LARC patients treated with preoperative CCRT. Lee et al 30 reported that the TLG of the primary tumor in the initial 18 F-FDG PET/CT can be considered as a prognostic factor for neoadjuvant CCRT in patients with rectal cancer.…”