_____________________________________________________________________________________________________incidence of hematologic toxicity was low (1 G1; 1G2).Early response evaluated by instrumental re-staging after 3 months from the end of treatment was encouraging, since 8 patients achieved complete response and 8 a partial response.Among the 6 patients with at least 2 years of follow up, 3 patient developed a progression disease (1 local relapse an 2 distant metastasis) and 1 patient died of disease after 3 years from treatment.The patient who underwent to radiation boost after chemoradiation developed anal stenosis which required a permanent colostomy. Conclusion:SIB with VMAT combined with chemotherapy is quite feasible in anal cancer treatment.It easily allows different dose delivering to target at different risk of disease involvement.Split course schedule has not be more used because of acceptable acute toxicity profile, which was confirmed in conventional fractionation.A larger patient number and a longer follow-up are required to confirm our data.

_____________________________________________________________________________________________________incidence of hematologic toxicity was low (1 G1; 1G2).Early response evaluated by instrumental re-staging after 3 months from the end of treatment was encouraging, since 8 patients achieved complete response and 8 a partial response.Among the 6 patients with at least 2 years of follow up, 3 patient developed a progression disease (1 local relapse an 2 distant metastasis) and 1 patient died of disease after 3 years from treatment.The patient who underwent to radiation boost after chemoradiation developed anal stenosis which required a permanent colostomy. Conclusion:SIB with VMAT combined with chemotherapy is quite feasible in anal cancer treatment.It easily allows different dose delivering to target at different risk of disease involvement.Split course schedule has not be more used because of acceptable acute toxicity profile, which was confirmed in conventional fractionation.A larger patient number and a longer follow-up are required to confirm our data.