Joint Program in Nuclear Medicine

Esophageal Carcinoma and F-18 FDG PET Imaging

Pritinder K. Thind, MD
Alan J. Fischman, MD PhD

May 16, 2000

Presentation

Imaging Findings

Discussion

Treatment and Outcome:

• Fewer than 5% of patients are alive 5 years from the initial diagnosis
• Surgical resection is possible in about 40% of cases; residual tumor is frequent at the resection margins
• Post operative mortality of 20% due to fistulas, abscesses, and respiratory complications
• < 20% of patients who survive total esophagectomy are alive at 5 years
• Radiation and chemotherapy
• Single agent chemotherapy: decrease in tumor size in 15-25%
• Combinations with cisplatin: reduction in 30-60%
• Preoperative chemotherapy and radiation followed by surgery appears to prolong survival
• For incurable, surgically unresectable patients:
• Endoscopic dilatation
• Gastrostomy, jejunostomy
• Stent - to bypass the tumor
• Endoscopic fulguration of the tumor using lasers
• Most patients present with advanced disease

PET

• Typically FDG is used
• Assesses metabolic activity
• As opposed to size as used in CT
• Principle: biochemical changes often precede or are more specific than structural changes in the disease process
• Functional imaging modality: delineation of normal anatomic structures can be difficult
• Cannot define depth of invasion

CT versus PET: Rankin, Taylor et al.

• 25 patients with biopsy proven cancer underwent pre-operative staging
• PET was more sensitive in detecting small nodal metastases
• PET was not as sensitive in detecting peri-esophageal and left gastric lymph nodes because of poor spatial resolution and proximity to the tumor
• PET was more sensitive in detecting distant metastases
• Both are effective in detecting the primary tumor

CT and PET for Staging: Kole, Plukker et al

• 26 patients
• Visualization of primary tumor:
• CT: 81% of patients
• PET: 96% of patients
• Neither could reliably assess wall invasion
• Correlation with surgically assessed nodal status:
• CT: 62%
• PET: 90%
• Accuracy for determining surgical resection:
• CT: 65%
• PET: 88%
• Together: 92%
• Overall, PET had a higher sensitivity for nodal and distant metastases as well as a higher accuracy for determining resectability

Improvement in Staging with the addition of PET: Block, Patterson et al

• 58 patients
• PET improved the ability to classify patients as resection candidates
• PET identified sites that were accessible for biopsy and unsuspected metastases in 17 patients with unresectable disease
• Altered the course of treatment
• Advantages of PET: images based on tissue metabolism, 3D whole body images, can detect other primary cancers
• Disadvantages: uptake can occur at inflammatory sites, availability and cost

PET and SUVs: Fukunaga, Okazumi et al.

• 48 patients
• 23 patients with SUV >7 had a poor prognosis
• SUV theories
• May represent a growth rate measurement of residual cancer cells
• Recurrent cases with higher preoperative SUVs had shorter latency periods
• May be assessing tumor viability
• SUV can be a useful tool in assessing treatment effects and postoperative follow-up
• SUV
• Correlates with hexokinase activity of the resected specimen
• Can differentiate benign from malignant (cut-off of 2)
• Index for predicting prognosis prior to surgery

PET and Chemotherapeutic Response: Couper, McAteer et al

• 14 patients: imaging performed prior to and following chemotherapy (after 2 or 3 cycles)
• PET was able to detect responses post chemotherapy (range: complete response to 15% increase)
• PET can play a role in patient selection for continued treatment
• Can play a role in monitoring treatment in patients receiving palliative chemotherapy

¹¹ C-Choline PET Imaging

• Methyl —¹¹ C choline
• Choline is a blood constituent that penetrates cell membranes
• In tumors, choline integrates into phospholipids
• ¹¹ C-choline is phosphorylated in tumor cells where it remains: "chemical trap"
• As tumor cells replicate, the biosynthesis of cell membranes is fast
• Therefore, the uptake rate of ¹¹ C-choline in tumors is proportional to the rate of tumor duplication

¹¹ C-choline and FDG: Kobori et al

• 33 patients
• ¹¹ C-choline was more effective in detecting very small mediastinal metastases than FDG and CT
• Minimal size detected: 4mm
• ¹¹ C-choline was more sensitive in detecting small tumors than FDG
• ¹¹ C-choline was less useful in imaging the upper abdomen because it is normally taken up by the liver
• With ¹¹ C-choline and FDG, 85% of metastatic lymph nodes were detected in the upper abdomen and mediastinum

Role of PET

• Determining benign from malignant lesions
• Demonstrating primary tumor
• Limited use in loco-regional lymph node evaluation
• Detecting distant metastases and other primaries
• Determine surgical resection candidates
• Determine treatment response, i.e., to chemotherapy

References

Fukunaga T, Okazumi S, et al. Evaluation of esophageal cancers using fluorine-18-fluorodeoxyglucose PET. J Nucl Med 1998; 39:1002-1007.

Kole AC, Plukker JT, et al. Positron emission tomography for staging of oesophageal and gastroesophageal malignancy. British Journal of Cancer 1998; 78(4):521-527.

Kobori O, Kirihara Y, et al. Positron emission tomography of esophageal carinoma using 11C-choline and 18F-fluorodeoxyglucose. Caner 1999; 86:1638-1648.

Luketich J, Schauer P, et al. Role of positron emission tomography in staging of esophageal cancer. Ann Thorac Surg 1997; 64:765-769.

McAteer D, Wallis F, et al. Evaluation of 18F-FDG positron emission tomography in gastric and oesophageal carcinoma. The British Journal of Radiology, 72 (1999), 525-529.

Rankin SC, Taylor H, et al. Computed tomography and positron emission tomography in the preoperative staging of oesophageal carcinoma. Clinical Radiology (1998) 53, 659-665.

Click here to go to Joint Program in Nuclear Medicine home page and Copyright notice.