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Other Guidelines
Quality control in the locoregional treatment of breast cancer
Breast conserving treatment
BCT is a combination of a surgical excison aiming at
microscopically-free margins and of radiotherapy of the breast. It generally
applies to small (arbitrarily up to 4 cm) unifocal invasive breast cancer. The
aims are:
-
to achieve local control,
-
to preserve breast cosmesis.
The requirements for breast surgery are described in the previous
paragraph. In breast conservation, the surgeon aims at 1 cm free margins.
Requirements for breast radiotherapy are:
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high energy photons
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simulation and treatment planning
-
use of appropriate beam modifiers to achieve homogeneity of dose distribution:
dose should not exceed 110% and should not be under 95% of the prescribed dose
-
avoidance of heart, lung and contralateral breast irradiation
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interval between surgery and initiation of radiotherapy should preferably not
exceed 8 weeks.
Indications for BCT should take into account the risk factors for
local recurrence and the determinants for cosmetic outcome
[11][12].
The aim for BCT is to keep the breast relapse rate of invasive
cancer less then 1-2% per annum follow-up (<15% at 10 years)
[13][14].
If known risk factors indicate a higher risk for breast relapse (young age,
incompletely excised infiltrating or in situ cancer, impossibility to deliver
an adequate dose of radiation therapy), either a re-excision (when cosmetically
feasible) or mastectomy has to be considered
[15].
OUTCOME MEASURE: The breast relapse rate for invasive cancer after
BCT should not exceed 15% at 10 years.
OUTCOME MEASURE: Excellent or good cosmetic result from a patient's point of
view should be at least 80% at 3 years.
Recommendation: As radiation therapy substantially improves
breast tumour control (by a factor of 2-3), every patient (>95%) with invasive
cancer who have had breast conservation surgery must have had a consultation
with a radiation oncologist to ensure sufficient information has been given on
how to achieve the best tumour control with the least morbidity.
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