<prompt> The ideal timing of radiotherapy for WiIlms tumor after surgery is -Within 10 daysWithin 2 weeksWithin 2 monthsAny time after surgery  <response>: Ans. is a i.e. within 10 days The postoperative radiotherapy in Wilms tumour is staed within 10 days of surgery. Delay in staing radiotherapy beyond ten days leads to tumor cells repopulation and increases the relapse rate. 