Does the path length of vaginal cuff cylinder brachytherapy treatment as adjuvant therapy for endometrial cancer vary based on histology (serous, etc)?  

There was some thought that treatment of high risk histologies, positive LVI, or high Grade required a longer vaginal length be treated. Including 2/3 or full length. That is largely unsupported by high-quality data and would increase distal vagina toxicity in this population. Our clinic treats upp...

I don’t change the length of vaginal treatment for adjuvant brachytherapy alone based on histology.  The only thing I do differently is in high risk disease who need EBRT, I treat the larger length of vagina with EBRT followed by brachy boost to upper 3 cm only.

Anecdotally, my institution has seen a few mid vaginal recurrences in high-risk histology (serous/carcinosarcoma/clear cell) patients treated to a 'standard' distance of 3 cm of proximal vagina, which became very challenging salvage situations. Thus, I do change my treatment length based on histolo...

I also agree with what has been discussed above by @Neil K. Taunk and @Sushil Beriwal. We don't change the path length based on histology as there is limited data to support this.