Below is a recap of key presentations from the San Antonio Breast Cancer Symposium (SABCS), December, 2018.  Clinical data from two important Accelerated Partial Breast Irradiation (APBI) clinical trials were presented:

  • RAPID, a randomized trial of partial breast irradiation using 3-D conformal radiotherapy (3D-CRT)
  • Primary results of NSABP B-39/ RTOG 0413 (NRG Oncology): a randomized Phase III study of whole Breast Irradiation (WBI) vs Partial Breast Irradiation (PBI) for women with stage 0, I or II breast cancer

The RAPID trial and NSABP B-39/RTOG 0413 were both randomized trials that compared whole breast radiotherapy (WBI) with ABPI, which shortens the course of radiation,.

In the B-39 Trial, the rates of ipsilateral breast tumor recurrence (IBTR) at 10 years for WBI vs. APBI were 3.9% and 4.6%, respectively. The IBTR) rate differential between APBI and WBI was only 0.7%. (note: the abstract notes 4.1% vs 4.9%, but the actual presented data is reported here.  However, based on the pre-set study hazard ratio success criteria, APBI was not found to be equivalent to WBI.

Tissue sparing approaches offer a better cosmetic outcome but treatment with 3DCRT (twice a day regimen), as observed in the RAPID trial, did not support improved cosmesis, and in fact the investigators were unable to recommend this treatment.   Data on cosmesis for the B-39 Trial has not yet been reported.

APBI continues to demonstrate that treating the entire breast with radiation is not necessary. Two of the B-39 principle investigators discuss how brachytherapy in low risk patients (node negative) continues to be an appropriate alternative to WBI .

Study investigators: Robert Kuske, MD and Frank Vicini, MD

 

 

 

 

 

 

 

 

Cianna Medical is looking for your insights and feedback on the new APBI data and expanding utilization for brachytherapy!
If you are interested in sharing your thoughts in a brief phone survey, please email Marie Shaw: mshaw@merit.com