Cancer du sein traité exclusivement par l’association d’une irradiation externe et d’une curiethérapie exclusive : résultats à long terme

Modern Approaches for Breast Brachytherapy

Breast brachytherapy represents a radiation technique that can be utilized as both monotherapy and as a tumor bed boost following breast conserving surgery. As monotherapy, the rationale for brachytherapy is that the majority of residual disease and therefore recurrences occur in close proximity to the lumpectomy cavity; for boost treatment, brachytherapy represents a technique that provided a more conformal approach prior to 3D treatment planning, and more recently can be used in conjunction with oncoplastic surgery. Multiple guidelines are available to assist clinicians with patient selection for accelerated partial breast irradiation (APBI), and recent guidelines support brachytherapy as an appropriate technique to deliver APBI. Modern breast brachytherapy can be performed with interstitial or applicator-based brachytherapy with multilumen and strut devices offering the ability to provide greater skin, chest wall, and normal breast sparing than previous devices. Novel strategies are being evaluated, including high dose rate perioperative/intraoperative radiotherapy, permanent breast seed implants, and noninvasive breast brachytherapy. Additionally, studies are evaluating shorter courses of brachytherapy. Multiple Level I studies are now available supporting interstitial brachytherapy to deliver APBI while prospective data and the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 trial are available with applicator brachytherapy and provide standardized prescriptions, target volume definitions, and dosimetric goals.

The American Brachytherapy Society consensus statement for accelerated partial breast irradiation

PURPOSE

To develop clinical guidelines for the quality practice of accelerated partial breast irradiation (APBI) as part of breast-conserving therapy for women with early-stage breast cancer.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in breast cancer and breast brachytherapy in particular devised updated guidelines for appropriate patient evaluation and selection based on an extensive literature search and clinical experience.

RESULTS

Increasing numbers of randomized and single and multi-institution series have been published documenting the efficacy of various APBI modalities. With more than 10-year followup, multiple series have documented excellent clinical outcomes with interstitial APBI. Patient selection for APBI should be based on a review of clinical and pathologic factors by the clinician with particular attention paid to age (≥50 years old), tumor size (≤3cm), histology (all invasive subtypes and ductal carcinoma in situ), surgical margins (negative), lymphovascular space invasion (not present), and nodal status (negative). Consistent dosimetric guidelines should be used to improve target coverage and limit potential for toxicity following treatment.

CONCLUSIONS

These guidelines have been created to provide clinicians with appropriate patient selection criteria to allow clinicians to use APBI in a manner that will optimize clinical outcomes and patient satisfaction. These guidelines will continue to be evaluated and revised as future publications further stratify optimal patient selection.

[Brachytherapy of breast cancer]

For breast cancer, interstitial brachytherapy remains an accurate irradiation technique for delivering a high dose (increasing the local control) in a small volume (decreasing the toxicity). In this article, we present the technical data related to the breast brachytherapy proceeding, from the implantation of the vectors to the treatment itself, including the planning. The different indications of breast brachytherapy include all the breast irradiations focusing on the initial tumour bed (partial irradiation of the breast), such as boost, accelerated and partial breast irradiation (APBI) and second conservative radiosurgical treatment in case of ipsilateral in-breast recurrence. The results in terms of efficacy and toxicity are presented for each indication. Interstitial breast brachytherapy, performed according with the standard rules, remains a major technique for breast cancer treatment.