Authors: Matthew Binks (Division of Surgery, Gosford Hospital, Gosford, New South Wales, Australia), John Boyages (School of Medicine and Psychology, Australian National University, Canberra, Australian Capital Territory, Australia; Radiation Oncology, Icon Cancer Centre, Sydney, New South Wales, Australia), Hiroo Suami (Department of Health Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia), Nicholas Ngui (School of Medicine and Psychology, Australian National University, Canberra, Australian Capital Territory, Australia; Division of Surgery, Sydney Adventist Hospital, Sydney, New South Wales, Australia), Farid Meybodi (Division of Surgery, Sydney Adventist Hospital, Sydney, New South Wales, Australia), T. Michael Hughes (School of Medicine and Psychology, Australian National University, Canberra, Australian Capital Territory, Australia; Division of Surgery, Sydney Adventist Hospital, Sydney, New South Wales, Australia), Senarath Edirimanne (Division of Surgery, Sydney Adventist Hospital, Sydney, New South Wales, Australia; Nepean Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia)
Categories: Breast Surgery, boost radiotherapy, breast cancer, oncoplastic surgery, tumour bed
Source: Anz Journal of Surgery
Doi: 10.1111/ans.19212
Oncoplastic breast surgery – a pictorial classification system for surgeons and radiation oncologists (OPSURGE)
Authors: Matthew Binks, John Boyages, Hiroo Suami, Nicholas Ngui, Farid Meybodi, T. Michael Hughes, Senarath Edirimanne
Abstract
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.
Introduction
With advancements in breast cancer treatment and prognosis has come a greater appreciation for survivorship and quality of life. ^1^ , ^2^ The breasts are generally of great value to a woman's sense of self and her physical, psychological, social, and sexual well‐being. ^3^ , ^4^ Consequently, the progression of surgical techniques and the emergence of oncoplastic surgery (OPS) has been established as a critical component of breast cancer management.
OPS, the utilization of plastic surgical techniques to restore a woman's breast contour after undergoing breast‐conserving surgery, has considerably improved the quality of life of breast cancer survivors. ^5^ , ^6^ , ^7^
One particular concern regarding OPS is the surgeon's ability to effectively communicate the location of the tumour bed to the multidisciplinary team (MDT). ^8^ , ^9^ , ^10^ , ^11^ , ^12^ Local recurrence tends to be at the tumour bed and affects 2.2–10.5% of patients undergoing wide excision and adjuvant radiotherapy for breast cancer. ^5^ , ^13^ , ^14^ , ^15^ , ^16^ When administered to the tumour bed, boost radiotherapy reduces the risk of local recurrence. ^17^ , ^18^ , ^19^
Techniques used by the radiation oncologist to localize the tumour bed have proven less accurate when applied following OPS procedures. ^1^ , ^10^ , ^20^ , ^21^ , ^22^ For instance, dead space closure with minimal tension at the tumour bed is a key component of OPS and likely reduces seroma formation at the site after OPS procedures. ^23^ , ^24^ Consequently, previous scholars have advocated for improving interdisciplinary communication and developing a common clinical language among the MDT. ^10^ , ^25^ , ^26^
Knowledge of the exact location of the original tumour margin is imperative to both the surgeon in planning re‐excision and the radiation oncologist in planning boost radiotherapy. This publication introduces a new framework that classifies OPS procedures based on their implications for the tumour bed. It visually represents tumour bed alterations resulting from OPS, aiming to enhance treatment outcomes, particularly for patients who require post‐operative boost radiation.
Methods
A new classification system is proposed to assist nomenclature and communication between the surgeon, radiation oncologist and other members of the MDT.
The factors considered in this system The position and extent of the skin incision.The degree of distortion and displacement of the tumour bed margins.The interposition of flaps into the tumour bed, either glandular breast tissue or exogenous tissue.The degree of residual seroma in the tumour bed.
To maximize our framework's utility, it expands on the original Clough et al., 2010, framework, which classified OPS techniques as either Level I or Level II according to their complexity. ^1^ Similarly, it incorporates the concepts of volume displacement and replacement raised by Chatterjee et al. ^27^
Our pictorial atlas uses colour‐coded tumour bed margins to represent how each OPS framework category distorts the superior, inferior, medial, and lateral margins. The images also depict the skin incision used for each procedure, highlighting the incision's relationship to the tumour bed.
Ethics risk was deemed low, and approval was waived.
Results
The classification system consists of five categories (A‐D2) of tumour beds, encompassing the different patterns of tissue redistribution observed after OPS. Among the five categories, Type D tumour beds are characterized as being filled with a flap of tissue. Furthermore, Type D tumour beds are subdivided into D1 and D2, depending on whether the flap comprises intramammary or extramammary tissue, respectively. The classification system, OPSURGE (Oncoplastic Surgery for Surgeons and Radiation Oncologists) is detailed below.
Type A tumour bed
The Type A tumour bed is the result of traditional non‐oncoplastic wide local excision of breast cancer (Figs 1 and 2). The surgical technique used to create this tumour bed
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A simple skin incision placed directly over the tumour.
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No or minimal mobilization of glandular breast tissue.
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Absence of defect closure/breast tissue apposition, with resultant seroma formation.
Type B tumour bed
The Type B tumour bed is produced by level 1 oncoplastic techniques (Figs 1 and 2). Features A simple skin incision, often remote from the location of the tumour bed.Glandular breast tissue mobilization in a single or dual plane. Undermining of the nipple‐areola complex is common.Apposition of the walls of the tumour bed by primary suture repair typically leads to minimal seroma formation.Minor nipple‐areola complex repositioning.
Examples: dual plane undermining, Benelli round block mammoplasty.
Type C tumour bed
The Type C tumour bed is created using techniques involving significant volume displacement without secondary flaps (Figs 1 and 2). This category results from a variety of Level II oncoplastic techniques. Features Complex and extensive skin incision, which is often remote from the tumour bed.Significant glandular breast tissue mobilization and rearrangement to facilitate defect closure. The tumour bed margins are often significantly distorted and may be displaced from the original site of excision.The original breast shape and size are altered with a reduction of breast volume.There is usually minimal seroma.
Examples: Modified Lejour therapeutic mammoplasty, Wise pattern therapeutic mammoplasty for an inferior pole tumour, V‐mammoplasty, racquet mammoplasty, and Grisotti flap mammoplasty.
Type D tumour bed
The Type D class is produced by OPS techniques that fill the tumour bed with a flap. Type D tumour beds are subclassified as Type D1 when a secondary dermoglandular or glandular breast tissue flap is used or Type D2 when non‐breast tissue such as lipodermal or myocutaneous flaps are used (Figs 1 and 2). Features Complex and extensive skin incision that may be remote from the location of the tumour bedGlandular breast tissue is mobilized to varying degrees. D1 tumour beds involve significant mobilization in single or dual planes. D2 tumour beds are filled with extramammary tissue and, therefore, require less mobilization of breast tissue.The margins of a Type D tumour bed are separated by intervening flap tissue.Following a Type D1 procedure, the breast shape and size are altered with reduction of breast volume. A Type D2 procedure causes minimal change to breast size and shape.There is usually minimal seroma. When present, the seroma may be distant from the tumour bed.
Examples: Type D1: Wise pattern therapeutic mammoplasty for superior pole tumour with a dermoglandular flap based on an inferior pedicle.
Type D2: Partial breast reconstruction using chest wall perforator flaps (lateral intercostal artery perforator flap (LICAP), anterior intercostal artery perforator flap (AICAP), thoracodorsal artery perforator flap (TDAP), lateral thoracic artery perforator flap (LTAP)), latissimus dorsi mini‐flap, omental flap.
An overview of the framework and its relationship with the various OPS techniques is provided in Table 1. The characteristics of each tumour bed are summarized in Table 2.
Discussion
This paper describes a simple classification scheme, OPSURGE, to enhance communication between the surgeon and radiation oncologist about their respective crafts following breast‐conserving surgery. Local recurrence at the tumour bed remains a concern following breast‐conserving surgery. Patients with local recurrence suffer significant physical and emotional consequences. ^28^ , ^29^ , ^30^ In addition to wide local excision and adjuvant whole breast radiotherapy, boost radiotherapy remains an important element in local breast cancer control following breast‐conserving surgery. ^18^ , ^31^ , ^32^
The necessity of boosting radiotherapy following OPS has been questioned. ^10^ , ^33^ The additional operative margin taken with OPS may render additional means of local control superfluous, with studies finding reduced margin positivity compared to traditional breast‐conserving surgery. ^3^ , ^34^ , ^35^ For instance, the margin attained during a therapeutic mammoplasty for an inferior tumour is likely to be much wider than that for a superior pole tumour, with the former less likely to derive much benefit from a boost. However, without robust evidence to support such de‐escalation, means of adapting boost radiotherapy to advancements in OPS, such as our framework, are required to ensure its safe delivery. The boost is particularly important for tumours at higher risk of local recurrence, such as triple‐negative or HER2‐positive breast cancers or lesions with extensive intraductal component or lymphovascular invasion. ^10^
An individualized approach is, therefore, necessary when delivering boost radiotherapy. ^18^ , ^22^ The American Society for Radiation Oncology (ASTRO, 2018) advised that a boost should be considered for women with invasive disease unless the patient is over the age of 70 with hormone‐positive, low‐grade disease and with negative margins by at least 2 mm. Patients with in situ disease should be offered boost radiotherapy unless they are over the age of 50 and have screen‐detected, low or intermediate‐grade disease that is <2.5 cm in size and removed with >3 mm margins. ^36^
Accelerated partial breast irradiation (APBI) has emerged as a viable alternative to whole breast irradiation. ^37^ By specifically targeting the portion of the breast affected by cancer, APBI aims to reduce the irradiation of normal tissues and depends on a clear understanding of the tumour bed location similar to that for boost radiotherapy ^38^ Oncoplastic surgery has been seen as a relative contraindication to APBI, and our proposed framework may help increase its use in this setting. ^39^ , ^40^
The rearrangement of breast and extra‐mammary tissue that occurs with OPS significantly distorts the tumour bed and impairs the radiation oncologist's ability to identify and target it with boost radiotherapy. ^17^ The surgical incision, post‐operative seroma location and preoperative imaging have all proven unreliable landmarks in determining the tumour bed following OPS. ^2^ Intraoperative clip placement is an essential tool used by the surgeon to communicate the location of the tumour bed to the radiation oncologist. ^9^ , ^41^ However, even clip placement has significant limitations. Variable surgeon compliance with clip placement, use of clips for other purposes such as haemostasis and the lack of standardized placement methods mean that the information conveyed by intraoperative clip placement can be challenging to interpret. ^10^ , ^20^ , ^42^ Furthermore, intraoperative clips commonly migrate outside their original quadrant and may be significantly displaced from the expected position. ^30^ , ^41^ , ^42^ Consequently, clip placement is only effective if the radiation oncologist has a sound understanding of OPS techniques used in their facility and if clear lines of communication exist between the surgeon and radiation oncologist. Table 3 summarizes previous guidelines for tumour bed boost administration by Boyages et al., 2018, with the addition of our tumour bed classification. ^22^ Technological advancements such as continuous filament markers may further improve localisation in the future. ^43^
Metz et al., in 2022, highlighted the importance of communication between surgeon and radiation oncologist when planning OPS and recommended preoperative referral to an oncoplastic MDT. ^2^ With the increasing incidence of breast cancer, many MDT meetings are pressed for time, with an average of 2 min allocated to each patient's management in some MDTs. ^44^ , ^45^ Furthermore, finding a time for an additional oncoplastic MDT that suits the various clinicians involved can be difficult. ^45^ In addition, intraoperative findings and changes to the operative plan often require nuanced post‐operative adjustment of the radiation fields when planning a boost. Such adjustment depends on clear communication from the surgeon so that the radiation oncologist can interpret the planning CT scan, the location of tumour bed clips in relation to preoperative imaging and the histopathology report. ^33^ By providing a guide for communication, our framework offers an opportunity to clarify the position and distortion of the tumour bed following OPS for the radiation oncologist and has the potential to save clinician and MDT time.
To our knowledge, our framework is the first to prioritize the effects of OPS on the tumour bed. The framework detailed by Clough et al., 2010, is widely used to describe the various OPS techniques available in breast surgery. ^1^ This framework groups OPS procedures into two broad categories – Level I and Level II – based on the proportion of the breast removed, the degree of breast tissue rearrangement and the degree of technical difficulty they require. Other classification systems incorporate the concepts of volume displacement and volume replacement. ^27^ Such frameworks give little insight into the position and morphology of the post‐operative tumour bed, with significant overlap within groups. For example, using existing frameworks, OPS techniques that yield a Type C tumour bed would be classified as Level 2, as would those that produce very different Type D1 or Type D2 tumour beds, making such categorisation of little value to radiotherapy field planning. Table 4 summarizes previously reported OPS frameworks. ^1^ , ^27^ , ^46^ , ^47^ , ^48^ , ^49^ None directly consider tumour bed distortion.
Our framework prioritizes the impact of OPS on the tumour bed to provide a common language between specialties that has been called for by multiple consensus statements. ^10^ , ^26^ The pictorial atlas with colour‐coded tumour bed margins offers a clear insight into the breast's rearrangement following OPS for radiation oncologists less familiar with OPS techniques and will aid boost localisation if required. For example, cases involving a LICAP flap could have the normal tissue dose reduced by using more sophisticated volumetric modulated arc therapy (VMAT) techniques, whereby a ring‐shaped boost is administered around the edge of the flap as guided by clip markers and a planning CT (Fig. 2). ^50^
The use of a synchronous integrated boost (SIB) reduces overall treatment time without increased toxicity, ^51^ without differences in toxicity or cosmesis ^52^ and with equivalent local control outcomes. ^53^ VMAT allows radiation fields to be ‘sculpted’ to the patient, reducing normal tissue dosage such as that to the heart when treating the internal mammary chain and offers superior dose conformity, fewer hot and cold spots in the breast and normal tissues and faster treatment times than intensity modulated radiation therapy (IMRT). ^22^ Unpublished data from the ICON Cancer Centre from 28 centres across Australia shows that VMAT radiation use in non‐palliative patients with breast cancer increased from 9% in 2018 to 57% in 2023.
Furthermore, the surgical margin following breast surgery is usually asymmetrical, which has led to anisotropic boost administration to reduce normal tissue toxicity and local recurrence. ^54^ , ^55^ , ^56^ Instead of expanding the radiotherapy field symmetrically around the surgical clips (known as the CTV or clinical tumour volume) to obtain an isotropic PTV or planning tumour volume, an anisotropic PTV may be administered, whereby wide surgical margins are relatively spared from the field and the radiation is focused on the close margin(s). ^55^ , ^57^ While studies have found interobserver variability to be significantly increased when using anisotropic boost radiotherapy, an improved understanding of the post‐OPS tumour bed and the location of close margins, such technology may help minimize radiotherapy complications. ^54^ , ^55^ , ^56^ It is hoped that aids such as OPSURGE will improve the accuracy of boost radiotherapy and potentially assist with the safe and consistent administration of an anisotropic boost.
A limitation of our system is the interplay between local excision and axillary management. Minimal access breast surgery involves performing sentinel node biopsy via the incision used for wide local excision of the primary tumour. ^58^ , ^59^ In such instances, the axilla or internal mammary chain is accessed by transecting the posterolateral or posteromedial walls of the tumour bed, respectively. While such procedures will lead to additional deformity of the breast, OPSURGE will clarify the expected tumour bed changes after the subsequent OPS technique used to reconstruct the breast. Further, with the increasing use of preoperative PET‐CT scanning and more effective systemic therapy, the IMC often remains unexplored and is instead treated with radiation. In addition, micrometastasis to an axillary sentinel node is more likely to be treated with radiation rather than a subsequent axillary dissection. ^60^ , ^61^
OPSURGE is an aid and depends on individual clinicians' compliance with established means of tumour bed identification. Standardized and disciplined usage of intraoperative clips, frequent interaction between team members and interdisciplinary education regarding local OPS techniques are fundamental to effectively administering boost radiotherapy. ^2^ , ^10^ , ^20^
In addition, further research is required to correlate data related to our surgical framework category, the boost volume and the technique used with cosmetic, local control, and toxicity outcomes, including breast oedema. ^62^
Conclusion
OPS grows with each passing decade. Integrating boost radiotherapy and OPS is an evolving sphere of breast cancer management and requires a mutual understanding between the oncoplastic surgeon and radiation oncologist. The OPSURGE framework aims to overcome the limitations of existing OPS frameworks concerning tumour bed distortion and identification and seeks to enhance the adaptation of adjuvant radiotherapy to OPS.
Author contributions
Matthew Binks: Writing ‐ review and editing. John Boyages: Conceptualization; supervision; writing ‐ review and editing. Hiroo Suami: Conceptualization; writing ‐ review and editing. Nicholas Ngui: Conceptualization; writing ‐ review and editing. Farid Meybodi: Conceptualization; writing ‐ review and editing. T Michael Hughes: Conceptualization; writing ‐ review and editing. Senarath Edirimanne: Conceptualization; supervision; writing ‐ review and editing.
Conflicts of interest
None declared.