International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationClinical Usefulness of 18F-Fluorodeoxyglucose-Positron Emission Tomography in Patients With Locally Advanced Pancreatic Cancer Planned to Undergo Concurrent Chemoradiation Therapy
Introduction
Pancreatic cancer is one of the most fatal malignancies, with 35% of patients presenting with locally advanced disease at the time of diagnosis (1). Locally advanced pancreatic cancer (LAPC) involves a greater potential for both distant metastasis (DM) and local progression, with a median survival of 8 to 12 months 2, 3. In an attempt to improve treatment outcomes, 3 randomized controlled trials demonstrated the benefits of upfront chemoradiation therapy (CRT) in the 1980s (4). Nevertheless, guidelines for the initiation of radiation therapy (RT) (upfront vs delayed/deferred) and for selecting candidates for RT vary significantly among institutions 5, 6, 7.
Rapid development of DM shortly after treatment often invalidates the need for locoregional treatments; thus, identifying those patients unlikely to benefit from RT is critical to spare them potentially toxic therapy and to prevent them from delaying the start of systemic therapy. Until now, the recent 2013 National Comprehensive Cancer Care Network guidelines have recommended conventional computed tomography (CT) or magnetic resonance imaging (MRI) for staging according to a defined pancreas protocol (5). In 2 recent randomized controlled trials, the results of which were contradictory about the role of CRT in LAPC, CT was the primary imaging modality for determining not only the resectability of primary tumors but also the presence of DM 8, 9.
With regard to the detection of DM, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is currently the most sensitive, noninvasive imaging modality, especially in identifying radiographically occult DM 10, 11. There is also growing interest in FDG-PET for predicting clinical outcome. However, the role of either coregistered FDG-PET or changes of FDG-PET in patients with LAPC is not well defined 12, 13. The objectives of our study were (1) to assess the role of coregistered FDG-PET in detecting radiographically occult DM in LAPC patients who were planned to undergo CRT; and (2) to study whether baseline FDG-PET and/or changes of FDG-PET after CRT can predict clinical outcomes in patients treated with CRT.
Section snippets
Patients
We identified 434 LAPC patients without evidence of DM based on radiographic evaluation with CT imaging (CT-M0) between October 2004 and November 2011 from the institutional database at a large academic medical center in Korea. The pretreatment evaluation included physical examination, laboratory tests, chest radiography, endoscopy, endoscopic ultrasonography, abdominal/chest CT, and biopsy. A multidisciplinary team, consisting of medical, radiation, and surgical oncologists and radiologists,
Usefulness of FDG-PET for selecting initial treatment
The study cohort consisted of 388 CT-M0 patients with diagnoses of LAPC based on conventional CT imaging. All patients underwent FDG-PET staging. The addition of FDG-PET imaging led to the detection of unsuspected DM in 33% of the CT-M0 patients (n=128), in whom upfront CRT was withheld as a first-line treatment. PET-M1 patients demonstrated a significantly worse overall survival (OS) than the 260 patients with PET-M0 disease (median OS, 9.1 vs 14.6 months, P<.001) (Fig. 1A). Of the 128
Discussion
To the best of our knowledge, this is the largest report to investigate the role of FDG-PET in LAPC patients undergoing CRT. Our unique findings are as follows: first, we found that integrating FDG-PET with conventional imaging tools facilitated the detection of 33% of unsuspected DMs in LAPC patients. This means that those patients with occult metastatic form could be spared from the unnecessary and potentially harmful treatment. Next, the incidence of early DM after completion of CRT was
Acknowledgments
The authors thank Mr. Dong-Su Jang, research assistant, Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea, for his help with the figures.
References (28)
- et al.
Phase III trial comparing intensive induction chemoradiotherapy (60 Gy, infusional 5-FU and intermittent cisplatin) followed by maintenance gemcitabine with gemcitabine alone for locally advanced unresectable pancreatic cancer. Definitive results of the 2000-01 FFCD/SFRO study
Ann Oncol
(2008) - et al.
High-dose helical tomotherapy with concurrent full-dose chemotherapy for locally advanced pancreatic cancer
Int J Radiat Oncol Biol Phys
(2012) - et al.
A randomized phase III study of radiotherapy alone or with 5-fluorouracil and mitomycin-C in patients with locally advanced adenocarcinoma of the pancreas: Eastern Cooperative Oncology Group study E8282
Int J Radiat Oncol Biol Phys
(2005) - et al.
Prognostic factors for survival and resection in patients with initial nonresectable locally advanced pancreatic cancer treated with chemoradiotherapy
Int J Radiat Oncol Biol Phys
(2012) - et al.
Human equilibrative nucleoside transporter 1 levels predict response to gemcitabine in patients with pancreatic cancer
Gastroenterology
(2009) - et al.
Correlation of Smad4 status with outcomes in patients receiving erlotinib combined with adjuvant chemoradiation and chemotherapy after resection for pancreatic adenocarcinoma
Int J Radiat Oncol Biol Phys
(2013) - et al.
18Fluorodeoxyglucose PET is prognostic of progression-free and overall survival in locally advanced pancreas cancer treated with stereotactic radiotherapy
Int J Radiat Oncol Biol Phys
(2010) - et al.
Cancer statistics, 1997
CA Cancer J Clin
(1997) - et al.
Pancreatic cancer
Curr Probl Surg
(1999) - et al.
Cancer statistics in Korea: Incidence, mortality, survival and prevalence in 2010
Cancer Res Treat
(2013)
Therapy of locally unresectable pancreatic carcinoma: A randomized comparison of high dose (6000 rads) radiation alone, moderate dose radiation (4000 rads + 5-fluorouracil), and high dose radiation + 5-fluorouracil: The Gastrointestinal Tumor Study Group
Cancer
Is there an optimal neoadjuvant therapy for locally advanced pancreatic cancer?
JOP
Combined radiochemotherapy in patients with locally advanced pancreatic cancer: A meta-analysis
World J Gastroenterol
Cited by (39)
New indications for PET in digestive oncology
2021, Medecine NucleairePrognostic value of <sup>18</sup>FDG PET/CT volumetric parameters in the survival prediction of patients with pancreatic cancer
2020, European Journal of Surgical OncologyCitation Excerpt :Maemura et al. 32 identified a correlation between a high SUVmax and the presence of distant metastasis while Sperti et al. [33] reporting limited survival for patients with SUVmax >4 (178 vs 265 days). It was also reported that a favourable decline in SUV following neoadjuvant chemo-radiotherapy, predicted overall survival as in the study by Chang et al [40] of 260 patients with locally advanced tumours supporting its role in biological monitoring of treatment efficacy. The volumetric parameters of 18 FDG PET/CT has been reported as independent risk predictors for OS and recurrence free survival in patients with resected PDAC [41–43].
ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in borderline-resected pancreatic cancer
2020, Clinical and Translational Radiation Oncology18F-FDG PET/CT in pancreatic adenocarcinoma: A role at initial imaging staging?
2019, Diagnostic and Interventional ImagingCitation Excerpt :In the multicenter prospective study of Ghaneh et al., FDG PET/CT changed the staging of pancreatic cancer in 56 of 261 patients (P = 0.001) and stopped resection in 58 patients who should have undergone surgery [45]. Furthermore, it must be emphasized that in the retrospective study of Chang et al. [37], among the 260 selected patients with PDAC without distant metastases on FDG PET/CT at staging, the incidence of early distant metastases after the completion of chemoradiation therapy was relatively low (13.1%), with longer survival (median overall survival, 14.6 months) and better locoregional control when compared to published data [46]. For potentially resectable or borderline PDAC, induction neoadjuvant treatment is frequently performed to make the pancreatic lesion resectable.
The Role of PET/CT in the Imaging of Pancreatic Neoplasms
2019, Seminars in Ultrasound, CT and MRIMolecular radionuclide imaging of pancreatic neoplasms
2019, The Lancet Gastroenterology and Hepatology
J. S. Chang and S. H. Choi contributed equally to this study.
Conflict of interest: none.