Positron Emission Tomography Imaging for Gastroesophageal Junction Tumors
Section snippets
PET for Initial Staging Evaluation
PET is considered a standard part of the staging workup for GEJ cancer owing to its ability to identify distant metastases and therefore incurable disease.1 In newly diagnosed esophageal cancer, it has been shown that 15%-20% of patients will be found to have distant metastases not identified by computed tomography (CT).2, 3, 4, 5 Integrated PET-CT is now widely available and is preferred, as it improves sensitivity compared with PET alone.6
However, the resolution of PET is limited for lesions
PET as an Initial Prognostic Marker
Multiple studies have examined the relationship between initial maximum SUV (SUVmax) and prognosis. Correlation between high SUV and diminished survival has been frequently reported, but whether SUVmax is an independent prognostic factor is less clear. Investigators at Memorial Sloan–Kettering Cancer Center (MSKCC) reviewed 50 patients who underwent surgery without preoperative therapy for esophageal adenocarcinoma and found that patients with SUVmax >4.5 had a 3-year survival of 57%, compared
PET as a Prognostic Marker After Induction Therapy
Because PET imaging can be obtained at various time points in the treatment process, serial scans may provide additional prognostic information based on metabolic response. PET appears to be a more specific marker of favorable treatment response after chemotherapy alone compared with chemoradiotherapy, likely owing to the confounding effect of radiation esophagitis.
In an initial report, German investigators studied 40 patients with GE junction adenocarcinoma who received 12 weeks of
Using PET to Direct Subsequent Treatment
The finding that PET can identify early responders and nonresponders to chemotherapy has prompted interest in using PET imaging to guide the choice of further therapy. Metabolic response evalUatioN for Individualization of neoadjuvant Chemotherapy in Oesophageal and oesophagogastric adeNocarcinoma (MUNICON), a multicenter phase II trial, demonstrated that early metabolic responders to chemotherapy had significantly better event-free survival compared with metabolic nonresponders (29.7 vs 14.1
PET for Radiotherapy Target Delineation
Precise delineation of the primary tumor is often difficult for esophagogastric carcinomas, which are intimately associated with the gastrointestinal mucosa and often lack clear borders detectable with standard cross-sectional imaging. Metabolic imaging with PET may visualize lymph node or submucosal spread of tumor that otherwise would not be visible using CT or endoscopic imaging. Multiple studies have evaluated the role of PET in tumor delineation and radiotherapy planning. However, there is
Conclusion
Because it can detect distant metastatic disease in patients otherwise thought to have curable disease, PET is now indicated in the initial workup of all patients with GEJ cancer. PET also may have prognostic value before, during, and after induction therapy. It is now hoped that PET will lead to therapeutic benefit for patients with localized disease by identifying nonresponders to induction therapy so that they can be switched to an alternate treatment regimen. Because PET can identify areas
References (52)
- et al.
The role of FDG-PET and staging laparoscopy in the management of patients with cancer of the esophagus or gastroesophageal junction
Gastroenterol Clin North Am
(2009) - et al.
FDG-PET has no definite role in preoperative imaging in gastric cancer
Eur J Surg Oncol
(2009) - et al.
Preoperative 18[F]-fluorodeoxyglucose positron emission tomography standardized uptake values predict survival after esophageal adenocarcinoma resection
Ann Thorac Surg
(2006) - et al.
Predictive value of initial PET-SUVmax in patients with locally advanced esophageal and gastroesophageal junction adenocarcinoma
J Thorac Oncol
(2009) - et al.
Positron emission tomography for assessment of the response to induction radiochemotherapy in locally advanced oesophageal cancer
Ann Oncol
(2002) - et al.
PET to assess early metabolic response and to guide treatment of adenocarcinoma of the oesophagogastric junction: The MUNICON phase II trial
Lancet Oncol
(2007) - et al.
Comparison of standardized uptake value-based positron emission tomography and computed tomography target volumes in esophageal cancer patients undergoing radiotherapy
Int J Radiat Oncol Biol Phys
(2010) - et al.
A systematic review on the role of FDG-PET/CT in tumour delineation and radiotherapy planning in patients with esophageal cancer
Radiother Oncol
(2010) - et al.
A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer
Radiother Oncol
(2006) - et al.
Impact of CT and 18F-deoxyglucose positron emission tomography image fusion for conformal radiotherapy in esophageal carcinoma
Int J Radiat Oncol Biol Phys
(2005)