The following international guidelines have been identified which include guidance on the use of hypofractionated radiotherapy for early breast cancer:
- The American Society for Radiation Oncology (ASTRO) guidelines on fractionation for whole breast irradiation, 2010
- The New Zealand Ministry of Health Guidelines for Management of Early Breast Cancer, 2009
- NICE Guidelines for early and locally advanced breast cancer, 2009
- Scottish Intercollegiate Guidelines Network (SIGN) guidelines, 2009
- BC Cancer Agency Breast cancer management consensus guidelines 2013
- European Journal of Medical Oncology (ESMO) guidelines on primary breast cancer diagnosis, treatment and follow-up, 2013
- German Society of Radiation Oncology (DEGRO) guidelines on radiotherapy of breast cancer, 2013
- Nice-Saint-Paul de Vence guidelines on adjuvant radiotherapy in the management of axillary node negative invasive breast cancer, 2013
The BC Cancer Agency consensus based guidelines for the management of early breast cancer include recommendations on the use of radiotherapy and recommend a hypofractionated radiotherapy regimen as standard. The guideline recommends the following dose fractionation for radiotherapy following breast conserving therapy (T1, T2; N0):
- Standard whole breast dose is 42.5 Gray (Gy) in 16 daily fractions
- Certain patients are at risk for inferior cosmetic outcome from the 16-fraction course. Extended fractionation should be considered for patients with very large breast size, and those with significant post-operative induration, oedema, erythema, hematoma or infection. Patients with these indications for extended fractionation should receive 45Gy in 25 daily fractions plus a boost dose of 10Gy in 5 fractions or 50.4 Gy in 28 daily fractions.
- If a boost is used, an additional dose of 6-16 Gy in 3-8 fractions is recommended.
The guideline recommends the following dose fractionation following mastectomy or BCS (T1,T2; N1, and T3;N0):
- Standard whole breast dose is 42.5 Gy in 16 daily fractions, chest wall dose is 40 Gy in 16 fractions, nodal dose is 37.5-40 Gy/16 fractions.
- Those at risk for increased toxicity post-BCS should be treated with the breast doses described above in the T1, T2, N0 section. Nodal dose should be 45 Gy/25 fractions.
- Those at risk for increased toxicity post-mastectomy, e.g. postoperative infection, and those undergoing reconstruction post-mastectomy should also be considered for extended fractionation. Patients with indications for extended fractionation post-mastectomy should receive 50.4 Gy in 28 daily fractions to the chest wall, and 45 Gy in 25 fractions to the nodal regions.
- For those with close or positive margins post-mastectomy, a higher chest wall dose (e.g. 42.5-44 Gy in 16 fractions) may be used, or a boost dose of 10Gy in 4 fractions or 16Gy in 8 fractions may be considered, if the anatomic area requiring the boost dose can be accurately delineated.