Wednesday, November 17, 2010

Radiation Therapy

For those without lymph node involvement, and those who want to leave radiation in the arsenal of tools available for treating unlikely recurrences, partial breast radiation therapy is now an option.

Whole breast radiation remains the "standard."

Here's what the radiation people have to say:

The Task Force proposed three patient groups: (1) a “suitable” group, for whom APBI outside of a clinical trial is acceptable, (2) a “cautionary” group, for whom caution and concern should be applied when considering APBI outside of a clinical trial, and (3) an “unsuitable” group, for whom APBI outside of a clinical trial is not generally considered warranted. Patients who choose treatment with APBI should be informed that whole-breast irradiation (WBI) is an established treatment with a much longer track record that has documented long-term effectiveness and safety.

Accelerated partial-breast irradiation is a new technology that may ultimately demonstrate long-term effectiveness and safety comparable to that of WBI for selected patients with early breast cancer. This consensus statement is intended to provide guidance regarding the use of APBI outside of a clinical trial and to serve as a framework to promote additional clinical investigations into the optimal role of APBI in the treatment of breast cancer.

Here's more info from the paper:

All patients considered for APBI should be candidates for breast-conserving therapy (no prior radiotherapy, no history of certain collagen vascular diseases, and not pregnant) and should be committed to long-term follow-up to evaluate for recurrence, second primary cancers, and treatment toxicity.

*this paper does NOT recommend partial breast radiation for anyone stage 1 under 50, and everyone over 60, although NO radiation is indicated for stage 1 women over 60!!!*

Here's some more info: To promote appropriate multidisciplinary cancer care, the Task Force strongly recommended that the decision to treat a patient with APBI should be made only after the patient's consultation with a radiation oncologist and review of the final pathology specimen.

Here's what Cedars Sinai has to say:

Mammosite Partial Breast Radiation Therapy (PBRT)

Mammosite is a type of partial breast radiation therapy (PRBT). It is an implant that uses a catheter to deliver high doses of radiation to a localized area to minimize the radiation effect on surrounding tissue such as the lungs and heart.

PRBT is not for everyone. In determining whether a patient is a candidate for the procedure, a physician will consider the size of the lump (<4 cm), how close it is to the skin, the size of the breast, and tumor size and characteristics.

PRBT may be a viable option for patients that plan to have a lumpectomy or other breast conserving surgery and patients who have already had radiation therapy.

PRBT requires five days of twice-daily treatments rather than the six weeks of Monday through Friday treatments required for standard radiation therapy.

PRBT is as effective in prevent breast cancer recurrence as whole breast radiation therapy.

My radiologist reported that this info. is for the "most tested" group, which is postmenopausal women over 60, under 70. She says that the studies / conferences she's attended recently only have 5 years of data for women under 45, and that data only involves hundreds, not thousands, of people.

She also reported that while the machine her office currently has, the trilogy medical linear accelerator, is good, it is not as good for partial breast as another machine that is available elsewhere. I don't know the name of that machine -- but it is what she used previously.


Newer methods of delivering radiation boost are available and are referred to as partial breast irradiation (PBI). PBI targets the radiation to the area of the breast most likely to have a cancer recurrence, the site around the lumpectomy. Three types of PBI treatments are used most commonly:
Multi-catheter brachytherapy (also known as "interstitial brachytherapy")
Balloon catheter brachytherapy (MammoSite® Radiation Therapy System)
Three-dimensional conformal external beam radiation therapy
These methods are all effective and allow the radiation oncologist to deliver a higher total dose of radiation to the area where the tumor was removed.

Current phase III research studies are underway to determine if partial breast irradiation (PBI), which involves a shorter course of radiation over 4-5 days, can be just as effective (good cosmesis, no increase in breast tumor recurrence, and no decrease in overall survival) as the current standard of 35 treatments over six or seven weeks of external whole breast radiation.


  1. Interbeam? << this is a question from a friend.

  2. Good question! This is when they zap the site of the tumor before closing you up.

    By the way, my radiologist said that if anyone jerks me around for having the wrong acronym for partial: imrt, pbi, etc., I should call him/her on it, since the profession uses several acronyms, they are interchangable.

    Anyway, the zapping:

    1) they may have to go back in and see to the margins, and I don't know how that runs with interbeam

    2) your surgeon has to have the machine in the operating theatre and use it or have the radiation oncologist there to use it -- not something that is currently common (now that a lumpectomy is outpatient / dr. office stuff)

    3) even partial is relatively experimental for under 45 patients, so it is enough of a fight to get partial if you're under 45 -- you'd have to be in a trial for that -- they are afraid of giving some of these treatments to those under 45.