Predictive value of 18-fluoro-deoxy-glucose-positron emission tomography (18F-FDG-PET) in the identification of responders to chemoradiation therapy for the treatment of locally advanced esophageal cancer

Abstract

Objective: To evaluate the utility of F-FDG-PET in predicting response to concomitant chemoradiation in locally-advanced esophageal cancer.

Summary background data: Approximately 25% of esophageal cancer patients experience a pathologic complete response (pCR) to preoperative chemoradiation therapy. Computed tomography, endoscopy, and endoscopic ultrasound are unable to identify patients experiencing a pCR. Growing evidence supports the use of F-FDG-PET in the staging of esophageal cancer in its ability to detect occult metastatic and lymph nodal disease. The identification of patients with a pCR to chemoradiation could potentially spare those patients the morbidity associated with a resection.

Methods: Eligibility criteria included T3-T4N0M0 or T1-T4N1M0 esophageal cancer. Patients underwent an initial F-FDG-PET before treatment and then repeated 4 to 6 weeks after chemoradiation, prior to the esophagectomy. Chemoradiation consisted of: cisplatinum, 5-fluorouracil, and radiation to a median dose of 50.4 Gy. Pathologic response was determined from a systematic review of the esophagectomy specimens.

Results: Sixty-four patients have completed therapy to date. Response was as follows: pCR 27%, pathologic residual microscopic (pCRmicro) 14.5%, partial response 19%, and stable or progressive disease 39.5%. A pretreatment standardized uptake value (SUVmax1hour) > or = 15 was associated with an observed 77.8% significant response (pCR + pCRmicro) compared with 24.2% for patients with a pretreatment SUVmax1hour < 15 (P = 0.005). Significant response was observed in 71.4% of patients with a decrease in SUVmax1hour > or = 10 compared with 33.3% when the SUVmax1hour decreased <10 (P = 0.004).

Conclusions: Pretreatment and posttreatment F-FDG-PET can be useful for predicting significant response to chemoradiation in esophageal cancer. These data should be considered in evaluation of patients for esophagectomy after chemoradiation.

FIGURE 1. Demonstration of response and restaging by ¹⁸F-FDG-PET. Left, Pre-chemoradiation imaging is displayed, revealing an abnormality consistent with malignancy within the esophagus (SUV 24), retroperitoneum, and celiac nodal station. Right, Post-chemoradiation imaging is displayed revealing resolution of the abnormality within the esophagus, retroperitoneum, and celiac nodal station. Interval development of a left supraclavicular lymph node is noted.