Radiotherapy (radiatio; radiation therapy) is used adjuvantly to surgical and drug therapy. Ionizing radiation is used to cause maximum damage to tumor tissue while sparing healthy tissue. Radiation therapy destroys any tumor cells that may remain in the body after surgery. Radiation therapy thus reduces the risk of tumor recurrence and tumor mortality. Adjuvant (“supportive”) radiotherapy is recommended:
- After breast-conserving surgery (BET).
- Standard: whole breast radiotherapy with a dose of 40-50 Gy Option: hypofractionation with a total dose of 40 Gy. (Higher single doses have higher biological effect and require lowering of total dose and number of irradiations. (Advantage: less time required (3-5 weeks), same effectiveness, good tolerability). Standard therapy in Canada and England; now also standard in GermanyNote: The new multicatheter brachytherapy, an “accelerated” partial breast irradiation, reduces radiotherapy to 5 days.Current (guideline 2012): recommendation currently only for older patients because of feared late cardiac toxicity (after > 10 years):
- Without chemotherapy
- With small tumors
- Without lymph nodes
- + additional circumscribed, local dose saturation of the tumor bed, so-called boost irradiation with 10-16 Gy (it reduces the local recurrence rate in all age groups).
Note: Adjuvant radiotherapy reduces the local recurrence risk (recurrence of disease (recurrence) at the same site) after breast-conserving therapy of DCIS (ductal carcinoma in situ) by up to 50%.
- Standard: whole breast radiotherapy with a dose of 40-50 Gy Option: hypofractionation with a total dose of 40 Gy. (Higher single doses have higher biological effect and require lowering of total dose and number of irradiations. (Advantage: less time required (3-5 weeks), same effectiveness, good tolerability). Standard therapy in Canada and England; now also standard in GermanyNote: The new multicatheter brachytherapy, an “accelerated” partial breast irradiation, reduces radiotherapy to 5 days.Current (guideline 2012): recommendation currently only for older patients because of feared late cardiac toxicity (after > 10 years):
- After ablatio mammae (mastectomy),
- Assured benefit in high risk: T3, T4 tumors, > 3 lymph nodes.
- Reduction in local recurrence rate (recurrence of tumor at a previously treated site).
- Prolongation of survival
- Questionable benefit at intermediate risk (2012 guidelines: Benefit Early Breast Cancer Trialists’ Collaborative Group, 2014 meta-analysis.
- T1, T2 tumors, 1-3 lymph nodes, and presence of other risk factors such as blood, lymphatic vessel invasion, grading G3
- ≥ pT2 tumor without lymph node involvement.
- Assured benefit in high risk: T3, T4 tumors, > 3 lymph nodes.
- After surgery preinvasive lesions
- Ductal carcinoma in situ (DCIS): indication for postoperative adjuvant radiotherapy after breast-conserving surgery (BEO).
- It reduces the rate of invasive and noninvasive local recurrence.
- Boost irradiation does not add any effect.
- Tamoxifen use may reduce the rate of noninvasive local recurrences. The rate of invasive carcinomas remains unaffected
- Discontinuation after individual risk-benefit assessment in:
- Elderly female patients (≥ 70 years).
- DCIS with low grading
- Lobular carcinoma in situ (LCIS) (lobular neoplasia (LIN)): No indication for postoperative adjuvant radiotherapy.
- Intraductal atypical hyperplasia (ADH): No indication for postoperative adjuvant radiotherapy (supportive radiotherapy after surgery).
- Ductal carcinoma in situ (DCIS): indication for postoperative adjuvant radiotherapy after breast-conserving surgery (BEO).
- Partial breast irradiation (PBI) or accelerated partial breast irradiation (APBI): Radiotherapy limited to partial areas of the breast as PBI or APBI as the sole form of irradiation is not a standard of care. It is:
- Subject to study
- Possibly an option for patients in whom homogeneous irradiation of the entire breast is not feasible
- Intraoperative radiotherapy (IORT): IORT as the sole intraoperative radiotherapy (radiotherapy during surgery) is not a standard of care. It is given immediately after surgical tumor extirpation as a single-stage radiotherapy treatment limited to the tumor resection cavity with application of a total dose considered curative by:
- Electrons of a linear accelerator (= IOERT).
- Orthovolt therapy with 50 kV X-rays from a conventional X-ray machine.
- Balloon brachytherapy technique
Intraoperative radiotherapy (IORT) versus classical external beam radiotherapy of the breast (EBRT, Engl.external beam radiotherapy, external body radiation therapy): Intraoperative radiotherapy, which may be considered for selected patients with single tumor sites at early stages, was compared with conventional external breast irradiation; patients were followed for a median of 8.6 years. As a result, the recurrence rate and mortality rate due to breast cancer were almost the same in both groups.
- Radiotherapy (radiation therapy) of advanced or unresectableTumor (LABC: locally advanced breast cancer): Radiatio only if no operability can be achieved by system therapy (standard therapy: primary neoadjuvant system therapy, followed by surgery and postoperative Radiatio).
- Radiation therapy of the infraclavicular and supraclavicular lymph nodes is recommended in the case of
- > 3 axillary lymph nodes affected.
- Infestation of level III of the axilla
- Indication for irradiation of the axilla (residual tumor in the axilla).
- Axillary irradiation is recommended
- When the residual tumor in the axilla (armpit).
- When there is clear clinical involvement and axillary dissection (removal of lymph nodes from the axilla) has not been performed.
Radiotherapy of parasternal lymph nodes is generally not recommended. Further notes
- European long-term EORTC study: boost radiation in the former tumor area after breast-conserving surgery (BET) can prevent local recurrence (reappearance of tumor at a previously treated site) in the operated breast; this benefited esp. patients younger than 50 and women with ductal carcinoma in situ (DCIS) who received a higher dose (reduction in the rate of local recurrence from 31 to 15%); furthermore, women with a high-grade tumor had the greatest benefit.
- Radiatio after breast-conserving surgery: a reduced dose and partial breast irradiation achieved comparable tumor control in terms of rates of local recurrence (recurrence of tumor at a previously treated site) and all-cause mortality (all-cause mortality).
Solitary brain metastases.
In the presence of a maximum of four solitary brain metastases (lesion < 3 cm), these are irradiated with the so-called single-shot technique. Bone metastases
On the skeleton, vertebral bodies, femurs, pelvis, ribs, sternum, cranial dome, and humerus are affected in descending frequency. Indications for radiatio (radiation therapy) are:
- Local pain
- Risk of fracture
- Mobility and functional limitations
- Neurological symptoms (emergency: spinal cord compression).
- Pathological fractures (if not surgically treatable).
- Postoperative after surgical treatment of bone metastases, if no RO resection (removal of the tumor in healthy tissue) could be achieved.
