Long-term results of intraoperative multicatheter breast implant (IOMBI) for accelerated partial breast irradiation (APBI) on early breast cancer patients

BACKGROUND AND PURPOSE

Multicatheter breast brachytherapy is a standard technique for accelerated partial breast irradiation (APBI) in early breast cancer patients. Intraoperative multicatheter breast implant (IOMBI) followed by perioperative high-dose-rate brachytherapy (PHDRBT) offers a novel and advantageous approach. We present long-term oncological, toxicity, and cosmesis outcomes for a well-experienced single institution.

MATERIALS AND METHODS

Eligible women aged ≥ 40 years with clinically and radiologically confirmed unifocal invasive or in situ ≤ 3 cm breast tumors underwent IOMBI during breast-conserving surgery. Patients meeting APBI criteria by definitive pathologic results received 3.4 Gy × 10fx with PHDRBT. Patients not suitable for APBI received PHDRBT-boost followed by WBRT.

RESULTS

A total of 171 patients underwent IOMBI during BCS, 120 patients (70.1 %) were suitable for APBI and 51 (29.8 %) for anticipated PHDRBT-boost. The median age was 61 years (range: 40-78), the median tumor size was 1.1 cm (range: 0.2-3.5), with a histological diagnosis of invasive ductal carcinoma in 78.9 % and ductal in situ in 21.1 %. A median of 9 catheters (range: 4-14) were used. For APBI, the median CTV and V100 were 40.8 cc (range: 8.6-99) and 35.4 cc (range: 7.2-94). The median of healthy breast tissue irradiated represents 7.2 % (range: 2.3-28 %) and the median local treatment duration was 10 days (range: 7-16). With a median follow-up of 8.8 years (range: 0.3-16.25), the 8-year local, locoregional, and distant control rates were 99 %, 98.1 %, and 100 %. G1-G2 late-toxicity rate was 53.4 %. Long-term cosmetic evaluation was excellent-good in 90.8 %.

CONCLUSION

IOMBI&PHDRBT program reports excellent long-term oncological outcomes, with a reduction from unnecessary irradiation exposure which translates into low long-term toxicity and good cosmesis outcomes, especially on well-selected APBI patients.

Analysis of the changes induced by bevacizumab using a high temporal resolution DCE-MRI as prognostic factors for response to further neoadjuvant chemotherapy

BACKGROUND

Antiangiogenic drugs are being used in the treatment of locally advanced breast cancer. The effect of these drugs can be monitorized using high temporal resolution dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

PURPOSE

To evaluate changes in tumor microvasculature induced by bevacizumab and the usefulness of these changes predicting response to further neoadjuvant therapy.

MATERIAL AND METHODS

Seventy patients with locally advanced breast cancers were treated with one cycle of bevacizumab followed by neoadjuvant therapy, combining bevacizumab and cytotoxic chemotherapy. Two DCE-MRI were performed before and after bevacizumab. Changes in tumoral volume, pharmacodynamic curves, and pharmacokinetic variables (K(trans), Kep, Ve, AUC90) in a ROI (ROI 1) encompassing the entire tumor and in another ROI (ROI 2) in the area of higher values of K(trans) were analyzed. Correlations with pathological response were made: parametrical and non-parametrical statistical analysis and ROC curves were used; a P < 0.05 was considered significant.

RESULTS

Significant changes in tumoral volume (-4%), pharmacodynamic curves, and pharmacokinetic variables in ROI 1 K(trans) (-45%), Kep (-38%), Ve (-11%), and AUC90 (-44%) and ROI 2 K(trans) (-43%), Kep (-39%), Ve (-5%), and AUC90 (-45%) were observed after bevacizumab (P < 0.05). The effect of bevacizumab was not different between responders and non-responders (P > 0.05), and these changes could not predict response to further neoadjuvant therapy.

CONCLUSION

Bevacizumab induces remarkable tumoral volume, pharmacodynamics, and pharmacokinetic changes. However, these changes could not be used as early predictors for response to further neoadjuvant therapy.