Impact of PET-CT on primary staging and response control on multimodal treatment of esophageal cancer.

Background: The predictive value of positron emission tomography-computed tomography (PET-CT) in primary staging and response control in patients with esophageal carcinoma (EC) is under discussion. In the present study initial staging and metabolic response of PET-CT was correlated with tumor regression and survival in patients with multimodal treatment of EC.

Methods: The authors conducted a retrospective analysis on a prospective database for 83 patients with EC (42 squamous cell, 39 adenocarcinoma, 2 anaplastic carcinoma) undergoing PET-CT for primary staging. Twenty-four of the patients underwent primary esophagectomy, 9 had palliative treatment, and 50 neoadjuvant radiochemotherapy (cisplatin, 5-fluorouracil; 50.4 Gy). The PET-CT study was repeated 6 weeks after induction of chemotherapy and compared with endoscopic ultrasound (EUS). For response control, the metabolic response (tumor standardized uptake value [SUV] reduction) was correlated with histopathologic (ypT0-4) and histomorphologic response (tumor regression) and survival.

Results: At primary staging 81 of 83 EC (97.5%) showed an increased SUV uptake correlating with the EUS tumor stage. Suspicious lymph nodes were detected in 51 (61.4%) patients by PET-CT and 66 (79.5%) were detected by EUS. Fifteen patients had additional findings on PET-CT examination leading to a change in therapy in 9 patients (10.3%). Of 50 patients receiving a second PET-CT study, a SUV reduction >50% correlated with major histomorphologic response (tumor regression grade 4, <10% vital tumor cells) and histopathologic response (ypT0 ypN0). Furthermore, these patients showed a significantly increased survival (33.1 ± 3.5 months) compared to non-responders (21.7 ± 3.3 months; p = 0.02) and patients after primary surgery (29 ± 3.2 months; p = 0.05).

Conclusions: The present study shows that PET-CT is a valuable tool for primary staging and response control in multimodal treatment of patients with EC.