After breast conserving surgery, margins clear

Margins <3mm wider excision recommended prior to adjuvant RT

Two-field tangential beams
- 4250 cGy in 16 fractions or 5000 cGy in 25 fractions

- or partial breast treatment (one week) as per OCOG study
- Margins of >3mm are recommended (deep margin is an exception if went to fascia)

- Boost can be applied if patient declines re-excision

SEGMENTAL RESECTION

Lymph Node Negative

Tangential breast fields
- 4250 cGy in 16 fractions

- 5000 cGy in 25 fractions

- 4500 cGy in 20 fractions

Or partial breast treatment (one week) as per OCOG study (for tumors < 3cm)

1-3 positive nodes

For both pre- and post-menopausal patients, regional nodal radiation is not recommended. Results from MA-20 will clarify whether nodal radiation is of benefit in this group.

- Radiation to breast and regional nodes, including IMC's:

  - 5000 cGy in 25 fractions

  - 4500 cGy in 20 fractions

- If > 10 nodes resected, may exclude axilla and treat IMC/supraclavicular area only

- tumor > 5 cm

- skin involvement

- muscle involvement

Radiation to chest wall and regional lymph nodes, including the IMC's

- 5000 cGy in 25 fractions

- 4500 cGy in 20 fractions

All patients to be referred for radiation oncologist consultation:

Pre-menopausal-regional node radiation in this setting is individualized.

Post-menopausal - If tamoxifen only used, regional nodal radiation, including IMC's, is recommended. When chemotherapy is used, regional nodal radiation in this setting is individualized.

- 4500 cGy in 20 fractions

- 5000 cGy in 25 fractions

Addendum: The data from the Danish update for pre-menopausal, 1-3+ nodes shows a survival benefit when CMF chemotherapy was given. There is no survival data from the Danish study in post-menopausal, 1-3+ nodes treated with chemotherapy as they were all treated with Tamoxifen. The absolute benefit of locoregional radiotherapy, in reduction of locoregional recurrence, is in the range of 5%.

Any number of nodes resected with 4 or more positive; pre- or post-menopausal

Chest wall and regional nodal radiotherapy, including IMC's:

- 5000 cGy in 25 fractions

- 4500 cGy in 20 fractions

If > 10 nodes resected, may exclude axilla and treat IMC/supraclavicular area only

Breast conserving surgery:

RADIATION BOOST

Primary recommendation:

further surgery to clear margins

If wider excision not an option

- 1000 cGy in 4 or 5 fractions if whole breast treated to 4250 cGy in 16 fractions

- Recommend 1000 cGys in 5 fractions or 1600 cGys in 8 fractions when 5000 cGys in 25 fractions used or 4500 cGy in 25 fractions (as an option in large breasted patients)

- Boost recommended to be sequential to tangent treatments

- All women under age 40 recommended to have boost even if clear margins

- Over age 40 boost for <3 mm margins at the discretion of RO

For post-mastectomy patients, no radiation recommended if margins close or focally positive. If grossly positive resection margin, there may be benefit from chest wall radiaiton. (Tamoxifen should also be considered (ER status may help decide which patient benefits) if patient had DCIS only). Bolus is recommended if radiation is delivered to chest wall. Details of bolus are at radiation oncologist's discretion.