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Updated: Jan 1, 2026
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
The Effectiveness of Intraoperative Clip Placement in Improving Radiation Therapy Boost Targeting After Oncoplastic
Matthew D Riina1, Ramy Rashad1, Stephanie Cohen1
1Tufts University School of Medicine, Boston, Massachusetts.
Purpose:
The role of surgical clips as markers of the tumor bed cavity for radiation therapy boost targeting after oncoplastic surgery is not well understood. Therefore, we sought to evaluate whether the placement of surgical clips can reduce interobserver variability in the delineation of the tumor bed cavities of oncoplastic surgery patients and ultimately determine an optimal number of clips to place.
Methods And Materials:
We reviewed records of 39 women with breast cancer who underwent oncoplastic breast surgery and adjuvant radiation therapy at our institution. Three radiation oncologists contoured tumor bed cavity volumes on planning computed tomography simulation images. Interobserver variability was measured both by a coefficient of variation of radiation oncologists contour volume and a concordance index defined as the quotient of the intersecting and aggregated volume of the contours. Patients were stratified by the number of surgical clips placed and compared by 1-way analysis of variance. Simple linear regression was used to evaluate the relationship of total excised volume and interobserver variability in patients with a sufficient quantity of surgical clips.
Results:
Interobserver variability in the delineation of the tumor bed cavity as measured by concordance index was significantly reduced in patients who received intraoperative surgical clips (F = 5.755; P = .001). A similar trend was seen in contour volume (F = 2.616; P = .052). Results of 1-way analysis of variance and post hoc analysis showed that 4 clips are effective and sufficient for reproducible delineation of the tumor bed cavity for the radiation therapy boost. Increasing excision volume does not result in an increase in interobserver variability (r2 = 0.00003).
Conclusions:
In oncoplastic surgery patients, intraoperative placement of surgical clips is beneficial and effective in improving the delineation of the tumor bed cavity for the radiation therapy boost. Four clips are necessary and sufficient for accurate boost targeting after lumpectomy with oncoplastic reconstruction.
Insights
Placing surgical clips after oncoplastic surgery significantly reduces variability in radiation therapy boost targeting. Four clips are sufficient for accurate tumor bed delineation, improving patient outcomes.
Area of Science:
- Oncology
- Surgical Oncology
- Radiation Oncology
Background:
- The precise delineation of the tumor bed cavity is crucial for effective radiation therapy boost targeting after oncoplastic surgery.
- The role of surgical clips as fiducial markers for this delineation remains unclear.
Purpose of the Study:
- To evaluate if surgical clips reduce interobserver variability in tumor bed cavity delineation.
- To determine the optimal number of surgical clips for reproducible contouring.
Main Methods:
- Retrospective review of 39 breast cancer patients undergoing oncoplastic surgery and radiation therapy.
- Three radiation oncologists contoured tumor bed cavities on CT simulation images.
- Interobserver variability assessed using concordance index and contour volume variation; analysis by number of clips and excision volume.
Main Results:
- Surgical clips significantly reduced interobserver variability in tumor bed cavity delineation (concordance index, P = .001).
- A trend towards reduced variability was observed in contour volume (P = .052).
- Four surgical clips were found to be effective and sufficient for reproducible delineation.
Conclusions:
- Intraoperative surgical clips are beneficial for improving tumor bed cavity delineation in oncoplastic surgery patients.
- Four clips are necessary and sufficient for accurate radiation therapy boost targeting post-lumpectomy with oncoplastic reconstruction.
