title: The benefit of PET/CT in the diagnosis and treatment of esophageal cancer.
abstract: BACKGROUND
  To evaluate the significance of PET/CT for the initial staging of esophageal cancer with emphasis on metastatic lymph node affection and detection of distant metastases. Furthermore, the aim of the work was to analyze the significance of PET/CT examination when evaluating the effect of neoadjuvant therapy.
  
  
  METHODS
  A set of 354 patients with esophageal cancer treated at the 1st Department of Surgery, University Hospital Olomouc and Medical Faculty at Palacky University in Olomouc between the years 20062012 were analyzed in a prospective study. The initial PET/CT examination was performed in 349 patients. We analyzed the benefit of this examination in regard to disease staging and based on the result, therapeutic strategy was determined. The initial PET/CT showed varying degrees of disease generalization in 102 patients, these patients were indicated for palliative or symptomatic therapy. In 247 patients, the disease was limited only to the esophagus and /or regional lymph nodes. After considering the patients overall condition and taking into account the wishes of the patient, 188 patients were indicated for neoadjuvant chemoradiotherapy (CRT); 32 patients did not complete this treatment. In 156 patients a follow-up PET/CT scan was performed after an average of 8.4 weeks following completion of neoadjuvant therapy. Based on this examination, a complete response- CR, was observed in 38 patients (24.4%), regression of the tumor in 89 (57.0%), stationary findings were seen in 10 (6.4%), and progression in 19 (12.2%). Ninety-seven patients were indicated for surgical resection; however, esophagectomy was only possible in 85 patients, in the remaining 12 patients only an explorative laparotomy was performed due to disease progression.
  
  
  RESULTS
  The initial PET/CT examination performed in 349 patients correctly described the extent of the disease in accordance with the histologically confirmed diagnosis in virtually all patients. A false positive result was seen in only 5 patients (1.43%). When evaluating the effect of neoadjuvant therapy, the patients were divided into groups based on the findings of the follow-up PET/CT after neoadjuvant therapy and their overall survival was evaluated. A significant difference (p=0.0004) in survival was observed between the groups based on the different reactions to neoadjuvant therapy (CR (n=38), regression (n=89), stationary findings (n=10), progression (n=19)) without taking into account the following treatment the patient received after neoadjuvant therapy. Patients who had a better response to neoadjuvant therapy had better survival results. There was also a significant difference in survival between the group of patients who completed neoadjuvant therapy and underwent radical surgical resection (n=85) versus those patients who completed neoadjuvant therapy but did not undergo subsequent surgery (n=59). The operated group had a significantly higher overall survival (p=0.003). The longest mean survival, 38.6 months (median 29.0 months), was achieved by the group of patients who completed neoadjuvant therapy, showed a complete response on the follow-up PET/CT, and underwent surgical resection. However, a significant difference was not observed (p=0.587) between the groups who underwent surgical resection and whose follow-up PET/CT results differed (regression or stationary findings). To date, the number of cases in the individual groups is not great enough to consider the obtained results conclusive, and we will continue to include more patients into the study and continue with the analysis.
  
  
  CONCLUSIONS
  The work documents the significance and benefit of PET/CT in the initial staging of esophageal cancer, especially in detecting metastatic disease- positive lymph nodes as well as distant metastases. PET/CT has great importance in determining therapeutic strategy. Furthermore, the significance of PET/CT in evaluating the effect of neoadjuvant therapy was also studied.Key words: esophageal cancer PET/CT neoadjuvant therapy esophagectomy.
authors.forename: K
authors.initials: K
authors.lastname: Vomackova
authors.forename: C
authors.initials: C
authors.lastname: Neoral
authors.forename: R
authors.initials: R
authors.lastname: Aujeský
authors.forename: R
authors.initials: R
authors.lastname: Vrba
authors.forename: M
authors.initials: M
authors.lastname: Stasek
authors.forename: M
authors.initials: M
authors.lastname: Myslivecek
authors.forename: R
authors.initials: R
authors.lastname: Formánek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000628:therapy; D016629:Esophagectomy / Q000379:methods*; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*