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

Background/aims: 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. method: 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. trial registration: clinicaltrials.gov: nct00658294 © 2015 ammann et al.