Can we rely on surgical clips placed during oncoplastic breast surgery to accurately delineate the tumor bed for targeted breast radiotherapy?

Ultrahypofractionated partial breast irradiation following oncoplastic surgery: secondary analysis of a phase II trial

PURPOSE

Although partial breast irradiation (PBI) is accepted as an effective and cosmesis-preserving technique for low-risk early-stage breast cancer following standard lumpectomy, data supporting PBI following oncoplastic surgery are sparse. We report prospective data in efforts to determine whether PBI can be safely utilized after oncoplastic surgery.

METHODS

Patients with low-risk stage 0-1 breast cancer following successful lumpectomy with optional oncoplastic reconstruction were enrolled on a phase II trial. Patients were treated with a modified Florence regimen to 30 Gy in 5 fractions on the Varian Edge radiosurgery system using IMRT or VMAT. Presurgical MRI, post-operative seroma and surgical clips were used to assist target delineation. The effect of oncoplastic surgery on radiation dosimetry and Breast Cancer Treatment Outcome Scale scores were assessed using student's t-test for continuous variables and chi-square for categorical variables.

RESULTS

From 2018 to 2022, 50 patients with 52 tumors were enrolled with 48% undergoing oncoplastic reconstruction. Although median PTV volumes were numerically larger in the oncoplastic group (266 cc vs. 223 cc), there were no statistically significant differences in PTV volumes, ratio of PTV to whole breast or mean heart or lung doses (p > 0.05). Mean baseline BCTOS aesthetic scores were 1.35 for standard lumpectomy vs. 2.52 for oncoplastic (p = 0.003). At long-term follow-up > 2 years, mean BCTOS aesthetic scores were 1.29 for standard lumpectomy vs. 1.35 for oncoplastic (p = 0.71). At a median follow-up of 46 months, there were no local recurrences.

CONCLUSIONS

When utilizing pre-treatment MRI, surgical clips and a relatively large PTV, PBI after oncoplastic surgery was safe and effective for appropriately selected patients. In combination with oncoplastic surgery, partial breast irradiation achieves excellent long-term cosmesis that improves over time.

First Results of the Primary Outcome of a Phase 2 Prospective Clinical Trial to Assess the Feasibility of Preoperative Radiation Boost in Patients With Breast Cancer

PURPOSE

A radiation therapy (RT) boost to the tumor bed is an important component of breast-conserving therapy in early breast cancer. This prospective phase 2 study assessed the feasibility of delivering the RT boost before surgery. We hypothesize wound complication rates to be comparable with postoperative RT and the target boost volume to be smaller than standard postoperative RT.

METHODS AND MATERIALS

This prospective phase 2 trial accrued 55 patients with clinically node-negative breast cancer eligible for breast-conserving therapy. Patients were treated with preoperative RT boost of 1332 cGy in 4 fractions, followed by lumpectomy and postoperative adjuvant whole breast RT to 3663 cGy in 11 fractions. The primary outcome was to demonstrate the incidence of grade 3 or more wound complications was not inferior to lumpectomy with standard postoperative whole breast RT and boost (6%-20%). We also compared the preop boost volume with a mock boost volume that would have been done after surgery.

RESULTS

Fifty-five women were enrolled between June 2021 and October 2022. Median age was 64 years old (range, 40-77 years). Forty-three patients had invasive cancers, and 5 had ductal carcinoma in situ. Median clinical tumor size was 13 mm (range, 5-26 mm). Grade 3 wound dehiscence requiring surgical revision occurred in 1 patient (2%). There were no other grade 3 adverse events. Three patients (6%) had grade 2 infections requiring antibiotics. The target boost volume was significantly lower than mock postoperative volume (11 cc vs 56 cc; P < .001) Cosmetic outcome at the first follow-up was very good or excellent in 87% of patients, and none had poor cosmetic outcomes.

CONCLUSION

The use of a preoperative RT boost followed by whole breast RT as administered here resulted in an acceptable primary outcome with a similar rate of postoperative wound complications and smaller boost volume compared with standard postoperative RT. This approach is currently under consideration for cooperative group phase 3 trial.

Oncoplastic breast surgery - a pictorial classification system for surgeons and radiation oncologists (OPSURGE)

INTRODUCTION

Changes to the tumour bed following oncoplastic breast surgery complicate the administration of adjuvant radiotherapy. Consensus guidelines have called for improved interdisciplinary communication to aid adjuvant boost radiotherapy. We propose a framework of tumour bed classification following oncoplastic surgery to enhance understanding and communication between the multidisciplinary breast cancer team and facilitate effective and more precise delivery of adjuvant boost radiotherapy.

METHODS

A classification system was devised by grouping oncoplastic procedures based on skin incision, tissue mobilization, tumour bed distortion, seroma formation and flap reconstruction. The system is supplemented by a colour-coded pictorial guide to tumour bed rearrangement with common oncoplastic procedures.

RESULTS

A 5-tier framework was developed. Representative images were produced to describe tumour bed alterations.

CONCLUSION

The proposed framework (OPSURGE) improves the identification of the primary tumour bed after initial breast-conserving surgery, which is imperative to both the surgeon in planning re-excision and the radiation oncologist in planning boost radiotherapy.

Delineation Errors Caused by Replication and Expansion Operations in Monaco

BACKGROUND

This study aims to investigate the errors in structure volume and shape caused by the replication, expansion, and merging operations of the Monaco system and analyze their influence on dosimetry evaluation.

METHODS

A retrospective collection of 30 patients undergoing radiotherapy was utilized. Cylinders with radii of 5, 10, and 30 mm were delineated in computerized tomography (CT) images from 10 patients with thoracic and abdominal issues, and the Margins function in Monaco was used to expand the margins by 0, 3, 5, and 10 mm in 2D mode. In 10 patients with vertebral metastases, the Margins function was utilized to replicate and merge targets, and the Copy Structure function was employed to replicate targets. Cross-CT replication was performed for the targets of 10 patients with nasopharyngeal carcinoma. The deviation between the processed structure volume and the ideal value was compared. The difference in the maximum dose (Dmax) before and after lens replication was evaluated in 10 patients undergoing whole-brain radiotherapy.

RESULTS

Monaco's Margins function increased the volume of the processed structure during the copying procedure. The margin error was equivalent to expanding the structure by 0.3-0.4 mm, and a margin error of 0.3-0.4 mm was produced in each expansion instance. The volume deviation for a cylinder with a radius of 5 mm was 12.99%. The Merge function of Margins copied substructures and merged them. The Copy Structure function did not alter the structure during copying, but the volume was reduced by less than 1% after copying across CT. Dmax after lens replication was higher than that before replication, with a median difference of 31.3 cGy for the left lenses.

CONCLUSION

Monaco's Margins function introduces errors in organ replication, expansion, and merging, resulting in incorrect dose assessment. Physicians should be mindful of the potential effects when utilizing them.

The King is in the altogether: Radiation therapy after oncoplastic breast surgery

Breast cancer is the most common malignancy, and the majority of the patients are diagnosed at an early disease stage. Breast conservation is the preferred locoregional approach, and oncoplastic breast conservation surgery is becoming more popular. This narrative review aims to discuss the challenges and uncertainties in target volume definition for postoperative radiation after these procedures, to improve radiation therapy decisions and encourage multidisciplinary.

Comparison of Tumor Bed Delineation Using a Novel Radiopaque Filament Marker Versus Surgical Clips for Targeting Breast Cancer Radiotherapy

BACKGROUND

Accuracy of tumor bed (TB) delineation is essential for targeting boost doses or partial breast irradiation. Multiple studies have shown high interobserver variability with standardly used surgical clip markers (CMs). We hypothesize that a radiopaque filament marker (FM) woven along the TB will improve TB delineation consistency.

METHODS

An FDA-approved FM was intraoperatively used to outline the TB of patients undergoing lumpectomy. Between January 2020 and January 2022, consecutive patients with FM placed after either (1) lumpectomy or (2) lumpectomy with oncoplastic reconstruction were identified and compared with those with CM. Six "experts" (radiation oncologists specializing in breast cancer) across 2 institutions independently defined all TBs. Three metrics (volume variance, dice coefficient, and center of mass [COM] deviation). Two-tailed paired samples t tests were performed to compare FM and CM cohorts.

RESULTS

Twenty-eight total patients were evaluated (14 FM and 14 CM). In aggregate, differences in volume between expert contours were 29.7% (SD ± 58.8%) with FM and 55.4% (SD ± 105.9%) with CM ( P < 0.001). The average dice coefficient in patients with FM was 0.54 (SD ± 0.15), and with CM was 0.44 (SD ± 0.22) ( P < 0.001). The average COM deviation was 0.63 cm (SD ± 0.53 cm) for FM and 1.05 cm (SD ± 0.93 cm) for CM; ( P < 0.001). In the subset of patients who underwent lumpectomy with oncoplastic reconstruction, the difference in average volume was 21.8% (SD ± 20.4%) with FM and 52.2% (SD ± 64.5%) with CM ( P <0.001). The average dice coefficient was 0.53 (SD ± 0.12) for FM versus 0.39 (SD ± 0.24) for CM ( P < 0.001). The average COM difference was 0.53 cm (SD ± 0.29 cm) with FM versus 1.25 cm (SD ± 1.08 cm) with CM ( P < 0.001).

CONCLUSION

FM consistently outperformed CM in the setting of both standard lumpectomy and complex oncoplastic reconstruction. These data suggest the superiority of FM in TB delineation.

Implementation of a Breast Intraoperative Oncoplastic Form to Aid Management of Oncoplastic Surgery

INTRODUCTION

Oncoplastic breast conservation surgery (BCS) uses concurrent reduction and/or mastopexy with lumpectomy to improve aesthetic outcomes. However, tissue rearrangement can shift the original tumor location site in relation to external breast landmarks, resulting in difficulties during re-excision for a positive margin and accurate radiation targeting. We developed the Breast Intraoperative Oncoplastic (BIO) form to help depict the location of the tumor and breast reduction specimen. This study seeks to assess physician perspectives of the implementation outcomes.

METHODS

From February 2021 to April 2021, the BIO form was used in 11 oncoplastic BCS cases at a single institution. With institutional review board approval, surgical oncologists (SOs), plastic surgeons (PSs), and radiation oncologists (ROs) were administered a 12-question validated survey on Acceptability of Intervention Measure (AIM), Intervention Appropriateness Measure (IAM), and Feasibility of Intervention Measure (FIM), using a 5-point Likert scale during initial implementation and at 6-month reassessment.

RESULTS

Twelve physicians completed the survey initially (4 SOs, 4 PSs, and 4 ROs). The mean scores for Acceptability of Intervention Measure, Intervention Appropriateness Measure, and Feasibility of Intervention Measure were high (4.44, 4.56, and 4.56, respectively). Twelve completed the second survey (5 SOs, 3 PSs, and 4 ROs). The mean scores were marginally lower (4.06, 4.21, and 4.25). There were no significant differences when stratified by number of years in practice or specialty. Free text comments showed that 75% of physicians found the form helpful in oncoplastic BCS.

CONCLUSIONS

The data indicate high feasibility, acceptability, and appropriateness of the BIO form. Results of this study suggest multidisciplinary benefits of implementing the BIO form in oncoplastic BCS.

Sometimes it is better to just make it simple. De-escalation of oncoplastic and reconstructive procedures

Simple breast conservation surgery (sBCS) has technically advanced onto oncoplastic breast procedures (OBP) to avoid mastectomy and improve breast cancer patients' psychosocial well-being and cosmetic outcome. Although OBP are time-consuming and expensive, we are witnessing an increase in their use, even for cases that could be managed with sBCS. The choice between keeping it simple or opting for more complex oncoplastic procedures is difficult. This review proposes a pragmatic approach in assisting this decision. Medical literature suggests that OBP and sBCS might be similar regarding local recurrence and overall survival, and patients seem to have higher satisfaction levels with the aesthetic outcome of OBP when compared to sBCS. However, the lack of comprehensive high-quality research assessing their safety, efficacy, and patient-reported outcomes hinders these supposed conclusions. Postoperative complications after OBP may delay the initiation of adjuvant RT. In addition, precise displacement of the breast volume is not effectively recorded despite surgical clips placement, making accurate dose delivery tricky for radiation oncologists, and WBRT preferable to APBI in complex OBP cases. With a critical eye on financial toxicity, patient satisfaction, and oncological outcomes, OBP must be carefully integrated into clinical practice. The thoughtful provision of informed consent is essential for decision-making between sBCS and OBP. As we look into the future, machine learning and artificial intelligence can potentially help patients and doctors avoid postoperative regrets by setting realistic aesthetic expectations.

Optimising post-operative radiation therapy after oncoplastic and reconstructive procedures

Surgical techniques for breast cancer have been refined over the past decades to deliver an aesthetic outcome as close as possible to the contralateral intact breast. Current surgery further allows excellent aesthetic outcome even in case of mastectomy, by performing skin sparing or nipple sparing mastectomy in combination with breast reconstruction. In this review we discuss how to optimise post-operative radiation therapy after oncoplastic and breast reconstructive procedures, including dose, fractionation, volumes, surgical margins, and boost application.

Accelerated Partial Breast Irradiation: Technological Advances and Current Challenges

Accelerated partial breast irradiation is a mature, standard-of-care treatment option for many women with early-stage breast cancer. In this paper, we discuss technological challenges and advances in the delivery of accurate and reproducible accelerated partial breast irradiation.

Breast Radiotherapy after Oncoplastic Surgery-A Multidisciplinary Approach

Oncoplastic breast surgery encompasses a range of techniques used to provide equitable oncological outcomes compared with standard breast surgery while, simultaneously, prioritizing aesthetic outcomes. While the outcomes of oncoplastic breast surgery are promising, it can add an extra complexity to the treatment paradigm of breast cancer and impact on decision-making surrounding adjuvant therapies, like chemotherapy and radiotherapy. As such, early discussions at the multidisciplinary team meeting with surgeons, medical oncologists, and radiation oncologists present, should be encouraged to facilitate best patient care.

Update on oncoplastic techniques in breast conserving surgery: algorithms for predictable results and custom-made reconstructions

Breast cancer surgery is going to be a relevant specialty involved in the multidisciplinary disease management, finalized to guarantee high performances on mortality reduction together with a quality of life improvement. The intellectual architecture of this field is characterized by its inclination to respect, sharing, empathy and scientific knowledge that can make it a high model of medical culture. In this context, oncoplastic breast conserving surgery is identified by special aesthetic sensitivities, as well as creativity and innovation. Knowing how to reshape the gland and fill the gaps, planning the targeted exeresis design, while anticipating the final outcome, respecting symmetries and ensuring first of all oncological safety, are the new skills that are required to the breast surgeon. Several tecniques could provide a refined surgical treatment but always challenging according to anatomical findings and patient expectations, as a systematic process of self-critical reflection, with the purpose to optimize criteria for improving therapeutic results.