What dose and target volume do you use for neoadjuvant chemoRT in a patient with a locally advanced uterine/endometrial cancer involving parametria, cervix, and the uterine fundus (no side wall involvement) requiring downstage to be eligible for surgery?

Her primary disease is too large for any brachytherapy; if substantial residual disease remains, how would you approach external beam boost?

2 Answers

Mednet Member

Radiation Oncology · Vanderbilt-Ingram Cancer Center

Answered on

Presuming that this is an endometrioid cancer - I would start with RT +/- chemo. There is potential for there to be sufficient shrinkage to facilitate brachytherapy boost. I do appreciate the link Dr. @Dr. First Last published, and would consider doing SBRT with a neoadjuvant dose how we would as per Dr. @Dr. First Last's paper (say 5 Gy x 4 rather than 5 Gy x 5) boost prior to planned surgical resection (assuming sufficient downstaging).

A separate comment I'll make about downstaging endometrial cancer - the focus of neoadjuvant radiation is to attempt to clear the vagina, parametria, and cervix, in (IMO) that order of importance, of disease that will lead to a positive margin.

If I was unable to fully cover the fundal extent of disease with brachytherapy in a patient who can undergo a hysterectomy, I would not worry too much, as that will be resected and it's not an issue of whether the margin will be positive or not.

If a non-endometrioid cancer, I think there is a strong argument to be made for considering neoadjuvant chemotherapy alone given upfront IIIB disease.

Mednet MemberInvited Expert

Radiation Oncology · Varian Medical Systems/Allegheny health network

Answered on

This is our series and approach; Vargo et al., PMID 25218303.

A few points in this series did have interstitial brachytherapy with the goal of focusing more on areas where downsizing will make surgery feasible.