Has anyone completed the 5 day radiation instead of the 20 for breast

I did 5 days for 1.6 cm DCIS stage 0, no nodes. I only had 1 mm margin, but the cancer center said because it was 1 mm at a focal point that it would be okay. I did this 4 years ago, 60cGy ea, 5 days, total 30 Gy. They usually do a little less now. I’ve had no recurrence.

It really depends on the type bc, and specifics. The FAST Forward clinical trial followed patients for 10 years. AI pulled this info together, that might be helpful:
The 5-day radiation regimen is specifically validated and indicated for patients meeting the following clinical profile:
Disease Stage: Early-stage invasive breast cancer or ductal carcinoma in situ (DCIS) typically classified in trials as pT1–3, pN0–1, M0.
Surgical Status: Patients who have undergone conservative breast-conserving surgery (lumpectomy) or, in specific contexts, those evaluated post-mastectomy.
Node Status: Primarily node-negative or with limited regional node involvement, depending on institutional and national oncology guidelines (such as NICE or ASTRO).

Best wishes for next week!

Thank you. My cancer sounds similar to yours. Helps me think I am making right decision.

I did not do the shorter version. Was diagnosed in 2023, 10 year follow-up study results were completed in 2026. At the time my oncologist at DFCI said there was not long term studies available. I probably still would have declined shorter radiation today- 10 years not long enough research for me.
Best of luck❤️

@triciaot
I also underwent 10 radiation sessions over 5 days for stage 1, no nodal involvement, post lumpectomy in January 2022. I have been on letrozole therapy since February 2022. No recurrence.

I also considered the genetic testing and family history. I do have an older sister who had DCIS but it was 17 years ago and no new/recurrence. No other breast, ovarian cancer in family. I had no genetic markers (although they now test for a few more than in 2022).

I’ve always been a bit concerned about the fat level I carry. Fat = estrogen, not great for estrogen positive cancer risk. I work to keep off the weight I lost during this whole process, probably anxiety driven. Even now at a BMI of 22 I have disportioncate fat to muscle. So I did decide on taking tamoxifen. I know all the right things to do to change that fat level . . . working on that. I fear I fail often.

I am sure my BMI is much higher than 22. Keep your head up. Don’t be too hard on yourself sending a hug.

@jnlnwool
I also did 5 days early morning and late afternoon. Mine was quite similar and that was three years ago. Maybe had the very slightest fatigue...more nerves driving to the center 2 x a day.
Hugs.

I did in September and did not have the redness or peeling. I use cream every day to prevent dryness.

Yes - no nodal involvement and 7 mm tumour. Five sessions over five days in Feb 2024 with minimal side effects. Followed by five years of Anastrozole. So far all ok.

I had the exact same question so I fully understand your concern. I had stage 1, ILC, 18mm. I had a lumpectomy (July 2026) with clean margins, and then 5 days of full breast radiation at 26 gy (vs spot) and completed the 5 days on September 25, 2026. I asked the radiologist how she made the decision for 5 days vs 15 (all other friends who have been through this did 15). She said that the longer treatment was typically always done but the medical community started testing fewer days and different doses (gy or gray) and it was shown that it was medically evidenced (can’t recall her term) that it was the same outcome for 5 days and better for the patient. She also said that other countries have been doing 5 days for many years. She commented that the hospital makes more money with a longer treatment and she is grateful her administration cares about the ethical side and what’s best for the patient versus prioritizing making money. On a related note I also had test called an AidaBreast test on the lump/tissue they removed which is used to assess the 10 year locoregional recurrence and predict the radiation benefit for early stage invasive breast cancer (this was approved by the FDA in April 2026). This gave me more specificity of the chance of recurrence even with radiation which is 6% which I’m not thrilled with but at least I know.

When I had the radiation I used MepitalOne film which can only be purchased from the UK (another one can be purchased on Amazon, but you most get MepitalOne). I had zero skin issues and sailed thru radiation. P.S. You could ask the same question on how they determined 5 days vs more. Push until you're satisfied. Good luck