<prompt> Sentinel biopsy most effective in:Cervix cancerEndometrium caVulval caVaginal ca  <response>: Vulval carcinoma the lymphatic spread is primarily by embolisation and only in later stages the spread is by permeation to fill the lymphatic channels The lymph node involvement follows a sequential pattern. the lymphatics of labia-superficialinguinal lymph nodes-deep inguinal lymph nodes-pelvic nodes Regional lymph nodes are assessed clinically and also by MRI.,Sentinel node lymphoscintigraphy,ultrasound and PET. D.C.DUTTA;S TEXTBOOK OF GYNECOLOGY,Pg no:335,6th edition 