Using 18F-Fluorodeoxyglucose Positron Emission Tomography to Monitor Clinical Outcomes in Patients Treated With Neoadjuvant Chemo-Radiotherapy for Locally Advanced Pancreatic Cancer

Abstract

BACKGROUND Pancreatic cancer ranks as the fourth leading cause of cancer death in the United States with five year survival ranging from 1-5%. Positron emission tomography (PET) is a metabolic imaging system that is widely used for the initial staging of cancer and detecting residual disease after treatment. There are limited data, however, on the use of this molecular imaging technique to assess early tumor response after treatment in pancreatic cancer. METHODS The objective of the study was to explore the relationship of early treatment response using the 18 F- fluorodeoxyglucose (FDG) PET with surgical outcome and overall survival in patients with locally advanced pancreatic cancer. FDG-PET measurements of maximum standardized uptake value (SUV) and kinetic parameters were compared to the clinical outcome. RESULTS Twenty patients were enrolled in the study evaluating neoadjuvant induction chemotherapy followed by concurrent chemoradiotherapy (chemo-RT) for locally advanced pancreatic cancer. All twenty patients had pre-study PET scans and a total of fifty PET scans were performed. Among patients who were PET responders (≥50% decrease in SUV after cycle 1), 100% (2/2) had complete surgical resection. Only 6% (1/16) had surgical resection in the PET non-responders (<50% decrease). Two patients did not have the second PET scan due to clinical progression or treatment toxicity. Mean survival was 23.2 months for PET responders and 11.3 months for non-responders (p=0.234). Similar differences in survival were also noted when response was measured using Patlak analysis. CONCLUSION FDG-PET can aid in monitoring the clinical outcome of patients with locally advanced pancreatic cancer treated with neoadjuvant chemo-RT. FDG-PET may be used to aid patients who could have complete surgical resection as well as prognosticate patients’ survival.

Preoperative 18[F]-fluorodeoxyglucose positron emission tomography/computed tomography predicts early recurrence after pancreatic cancer resection

“…There have also been patients who received perioperative radiotherapy for pancreatic cancer but for whom this approach was not associated with a longer survival [25,26]. In contrast, other studies have reported that FDG-PET facilitates the monitoring of the clinical outcome of older patients with locally advanced pancreatic cancer treated with neoadjuvant chemoradiotherapy [27]. Differences in radiotherapy effects in esophageal cancer and cancers of the head and neck have also been reported in association with differences in SUV values [28,29].…”

Resection of borderline resectable pancreatic cancer after neoadjuvant chemoradiation does not depend on improved radiographic appearance of tumor–vessel relationships

“…PET, however, can more reliably assess the viability of the cancer cells following treatment. Choi and colleagues [31] performed a small study of 16 locally advanced patients who received pre- and post-treatment 18 F-fluorodeoxyglucose (FDG) PET scans. They observed that patients exhibiting a ≥50 % decrease in SUV following neoadjuvant chemoradiation underwent successful resection while resection was uncommon in non-responders; however, only three patients in the entire cohort proceeded to resection.…”

Cancer-associated fibroblast-derived annexin A6+ extracellular vesicles support pancreatic cancer aggressiveness

“…Indeed, PDA patients classified as responders following chemotherapy protocol show either reduction or stagnation of the primary tumor (41). This is often associated with tumor cell death and appearance of necrotic areas associated with drastic modifications of the nearby environment of the resistant tumor cells (42,43). Indeed, this reactive stroma is associated with a new structural environment where CAFs and immune cells exhibit different abilities.…”