title: Outcome after Discontinuing Long-Term Benzimidazole Treatment in 11 Patients with Non-resectable Alveolar Echinococcosis with Negative FDG-PET/CT and Anti-EmII/3-10 Serology.
abstract: OBJECTIVE
  Benzimidazoles are efficacious for treating non-resectable alveolar echinococcosis (AE), but their long-term parasitocidal (curative) effect is disputed. In this study, we prospectively analyzed the potential parasitocidal effect of benzimidazoles and whether normalization of FDG-PET/CT scans and anti-Emll/3-10-antibody levels could act as reliable "in vivo" parameters of AE-inactivation permitting to abrogate chemotherapy with a low risk for AE-recurrence.
  
  
  METHODS
  This prospective study included 34 patients with non-resectable AE subdivided into group A (n = 11), followed-up after diagnosis and begin of chemotherapy at months 6, 12 and 24, and group B (n = 23) with a medium duration of chemotherapy of 10 (range 2-25) years. All patients were assessed by FDG-PET/CT examinations and anti-EmII/3-10 serology. Chemotherapy was abrogated in patients with normalization of FDG-PET/CT and serum anti-EmII/3-10 levels. These patients were closely followed-up for AE recurrence. Endpoint (parasitocidal efficacy) was defined by the absence of AE-recurrence >24 months after stopping treatment.
  
  
  RESULTS
  Normalization of FDG-PET/CT scan and anti-EmII/3-10 levels occurred in 11 of 34 patients (32%). After abrogation of chemotherapy in these 11 patients, there was no evidence of AE-recurrence within a median of 70.5 (range 16-82) months. However, the patients' immunocompetence appears pivotal for the described long-term parasitocidal effect of benzimidazoles.
  
  
  CONCLUSIONS
  The combination of negative FDG-PET/CT-scans and anti-EmII/3-10 antibody levels seem to be reliable parameters for assessing in vivo AE-larval inactivity after long-term benzimidazole chemotherapy.
  
  
  BACKGROUND
  clinicaltrials.gov: NCT00658294.
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital of Zurich, Zürich, Switzerland.
authors.forename: Rudolf W
authors.initials: RW
authors.lastname: Ammann
authors.affiliation: Institute of Radiology, Hirslanden Hospital, Zürich, Switzerland.
authors.forename: Katrin D M
authors.initials: KD
authors.lastname: Stumpe
authors.affiliation: Institute of Parasitology, University of Zurich, Zurich, Switzerland.
authors.forename: Felix
authors.initials: F
authors.lastname: Grimm
authors.affiliation: Institute of Parasitology, University of Zurich, Zurich, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Deplazes
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital of Zurich, Zürich, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Huber
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital of Zurich, Zürich, Switzerland.
authors.forename: Kaja
authors.initials: K
authors.lastname: Bertogg
authors.affiliation: Division of Nuclear Medicine, University Hospital Zurich, Zürich, Switzerland.
authors.forename: Dorothee R
authors.initials: DR
authors.lastname: Fischer
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital of Zurich, Zürich, Switzerland; Swiss HPB (Hepato-Pancreato-Biliary) Center, University Hospital of Zurich, Zürich, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Müllhaupt
mesh_terms: D000328:Adult; D000368:Aged; D000871:Anthelmintics / Q000008:administration & dosage*; D000909:Antibodies, Helminth / Q000097:blood; D001562:Benzimidazoles / Q000008:administration & dosage*; D016903:Drug Monitoring; D004443:Echinococcosis; D004444:Echinococcosis, Hepatic / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000871:Anthelmintics; D000909:Antibodies, Helminth; D001562:Benzimidazoles; C031000:benzimidazole