Inclusion Criteria:  Recurrent Ta-T1a (above muscularis mucosa) LOW GRADE bladder tumor Accept cystoscopy surveillance Main lession less than 10mm Less than 7 lesions Negative or low grade cytology No solid aspect  Exclusion Criteria:  previous High grade bladder cancer tumors previous Cis previous Upper Urinary Tract tumor previous pelvic radiotherapy hematuria meatal localisation