Evaluation of Sentinel Lymph Node Dose Distribution in 3D Conformal Radiotherapy Techniques in 67 pN0 Breast Cancer Patients

De-escalation of axillary irradiation for early breast cancer - Has the time come?

Introduction of sentinel lymph node biopsy, initially in clinically node-negative and subsequently in patients presenting with involved axilla and downstaged by primary systemic therapy, allowed for significant decrease in morbidity compared to axillary lymph node dissection. Concurrently, regional nodal irradiation was demonstrated to improve outcomes in most node-positive patients. Additionally, over the last decades, introduction of more effective systemic therapies has resulted in improvements not only at distant sites, but also in locoregional control, creating space for de-escalation of locoregional treatments. We discuss the data on de-escalation in axillary surgery and irradiation, both in patients undergoing upfront surgery and primary systemic therapy, with special emphasis on the feasibility of omission of nodal irradiation in patients undergoing primary systemic therapy. In view of the accumulating evidence, omission of axillary irradiation may be considered in clinically node-positive patients converting after primary systemic therapy to pathologically negative nodes on sentinel lymph node biopsy (preferably also with in-breast pCR), presenting with lower initial nodal stage, older age and were treated with breast-conserving surgery followed by whole breast irradiation. Omission of regional nodal irradiation in patients with aggressive tumor phenotypes achieving a pCR is under investigation. In patients undergoing preoperative endocrine therapy the adoption of axillary management strategies utilized in case of upfront surgery seems more suitable than those used in post chemotherapy-based primary systemic therapy setting.

Does the number of removed axillary lymphnodes in high risk breast cancer patients influence the survival?

Background

The decision making process for axillary dissection has changed in recent years for patients with early breast cancer and positive sentinel lymph nodes (LN). The question now arises, what is the optimal surgical treatment for patients with positive axillary LN (pN+). This article tries to answer the following questions:

Is there a survival benefit for breast cancer patients with 3 or more positive LN (pN3+) and with more than 10 removed LN?

Is there a survival benefit for high risk breast cancer patients (triple negative or Her2 + breast cancer) and with 3 or more positive LN (pN3+) with more than 10 removed LN?

In pN + patients is the prognostic value of the lymph node ratio (LNR) of pN+/pN removed impaired if 10 or less LN are removed?

Methods

A retrospective database analysis of the multi center cohort database BRENDA (breast cancer under evidence based guidelines) with data from 9625 patients from 17 breast centers was carried out. Guideline adherence was defined by the 2008 German National consensus guidelines.

Results

2992 out of 9625 patients had histological confirmed positive lymph nodes. The most important factors for survival were intrinsic sub types, tumor size and guideline adherent chemo- and hormonal treatment (and age at diagnosis for overall survival (OAS)). Uni-and multivariable analyses for recurrence free survival (RFS) and OAS showed no significant survival benefit when removing more than 10 lymph nodes even for high-risk patients. The mean and median of LNR were significantly higher in the pN+ patients with ≤10 excised LN compared to patients with > 10 excised LN. LNR was in both, uni-and multivariable, analysis a highly significant prognostic factor for RFS and OAS in both subgroups of pN + patients with less respective more than 10 excised LN. Multivariable COX regression analysis was adjusted by age, tumor size, intrinsic sub types and guideline adherent adjuvant systemic therapy.

Conclusion

The removal of more than 10 LN did not result in a significant survival benefit even in high risk pN + breast cancer patients.

To clip or not to clip the breast tumor bed? A retrospective look at the geographic miss index and normal tissue index of 110 patients with breast cancer

OBJECTIVE

Planning of breast radiation for patients with breast conserving surgery often relies on clinical markers such as scars. Lately, surgical clips have been used to identify the tumor location. The purpose of this study was to evaluate the geographic miss index (GMI) and the normal tissue index (NTI) for the electron boost in breast cancer treatment plans with and without surgical clips.

MATERIAL AND METHODS

A retrospective descriptive study of 110 consecutive post-surgical patients who underwent breast-conserving treatment in early breast cancer, in which the clinical treatment field with the radiologic (clipped) field were compared and GMI/NTI for the electron boost were calculated respectively.

RESULTS

The average clinical field was 100 mm (range, 100-120 mm) and the clipped field was 90 mm (range, 80-100 mm). The average GMI was 11.3% (range, 0-44%), and the average NTI was 27.5% (range, 0-54%). The GMI and NTI were reduced through the use of intra-surgically placed clips.

CONCLUSION

The impact of local tumor control on the survival of patients with breast cancer is also influenced by the precision of radiotherapy. Additionally, patients demand an appealing cosmetic result. This makes "clinical" markers such as scars unreliable for radiotherapy planning. A simple way of identifying the tissue at risk is by intra-surgical clipping of the tumor bed. Our results show that the use of surgical clips can reduce the diameter of the radiotherapy field and increase the accuracy of radiotherapy planning. With the placement of surgical clips, more tissue at risk is included in the radiotherapy field. Less normal tissue receives radiotherapy with the use of surgical clips.