Novel Tumor Bed Marking In Breast Cancer: Expanding Beyond Lumpectomy
Toni Storm, M.D., Surgical Medical Director, PeaceHealth Southwest Kearney Breast Center and Co-Director Compass Breast Specialists, Vancouver, WA.
VeraForm® placement to assist with localization and delivery of adjuvant radiation
Historically, lumpectomies resulted in a scar immediately over the lumpectomy site, dictating delivery of adjuvant radiation on scar location, and frequently on the presence of a seroma. Currently, the question persists as to the optimal means to help direct the radiation oncologist to effectively deliver radiation in the oncoplastic era. With oncoplastic surgery, the lumpectomy site rarely correlates with the incisional scar and presence or absence of a seroma can no longer be counted on to correlate with the lumpectomy bed.
This leaves us with the need to address the lumpectomy site differently and challenge the conventional approach. By using a continuous flexible fiducial marker, VeraForm, the surgeon can now mark the lumpectomy cavity in a more realistic 3-dimensional manner. This then allows the radiation oncologist to see the area of concern through the surgeon’s eyes, rather than guess where to set their fields. As such, the radiation oncologist can now triangulate much more precisely on the resection site and surrounding tissues. Further, as VeraForm is a low-profile, fine filament, it is not palpable for the patient. Any marker that is palpable can result in both patient anxiety and an inability to identify a subtle clinical change such as a small mass or thickened nodularity.
We have successfully deployed VeraForm in over 100 patients in lumpectomy applications, including Level 1 and Level 2 oncoplastic procedures, yielding excellent cosmetic results and without a single episode of marker discomfort or palpability which can commonly be experienced with another known radiopaque 3D marker.
More recently, we have successfully expanded applications of the VeraForm continuous marker beyond breast conserving surgery. One such usage has been the successful deployment of VeraForm during mastectomies where the tumor extended to the chest wall. VeraForm was placed in a locking helical pattern over the area of concern on the chest wall (pectoralis). This has been extremely beneficial to our radiation oncologists because after mastectomy, it’s frequently very difficult for them to identify the extent and exact location of the original tumor bed. Placing VeraForm into the chest wall allows the surgeon the flexibility to define the area of concern, versus noting a simple ‘spot’, such as normally seen by a clip. This more detailed placement allows the surgeon to communicate far more information to the radiation oncologist and identify the true area of concern.
In addition to lumpectomies and mastectomies, we now have experience with VeraForm deployment beyond the breast. Here is a specific example of one such case:
69-year-old woman with a history of Stage IB, grade 3 cervical cancer diagnosed 1994, status post TAH/BSO, chemotherapy and radiation. Stage IIIB, locally advanced, ER/PR positive, HER-2 negative, grade 3, IDC of the left breast with muscle involvement diagnosed 07/30/2010, now with left lateral chest wall recurrence, ER/PR 100/100, strong/moderate, HER-2 negative, IDC involving the left lateral chest inferior and lateral to the axilla. She was found to have this, on 10/31/2019, undergoing neoadjuvant dose-dense doxorubicin and cyclophosphamide followed by weekly paclitaxel.
MRI revealed: Patient is status post mastectomy with reconstruction. A left breast implant demonstrates normal signal. In the inferior aspect of the left axilla/lateral chest wall there is a large enhancing mass which measures 2.5 x 6.2 x 2.7 cm. The mass has extremely irregular borders and appears to extend between muscle layers posteriorly and to the skin.
She was then taken to the operating room undergoing wide local resection of the left lateral posterior chest wall malignancy to include involved skin, latissimus and serratus anterior with tissue mobilization and closure and placement of VeraForm.
VeraForm was placed as a running locking helix partially re-approximating the serratus along the transverse lie of the muscle fibers. Again, a VeraForm was placed in a running locking helix, this time along the anterior medial edge of latissimus demarcating this edge of the resection field. Consequently, these filaments can then be seen by the Radiation Oncologist with minimal artifact, allowing maximize adjuvant radiation delivery.
Given the location and extent of disease, placing a radiopaque filament to help target the adjuvant radiation is extremely helpful, both for allowing better delivery of radiation to the exact tumor bed and limiting radiation spray to other structures such as the heart, lungs and surrounding muscles. In this case, it’s important to note that the scar is inferior to the tumor bed and thus, the radiation oncologist cannot simply rely on the scar as a planning target for the boost.
Having VeraForm delineate the exact target area and volume provides accurate RT planning information for the radiation oncologist. While our case series continue to grow, we have begun to realize the benefits of utilizing this low-profile continuous marker not only in standard lumpectomy tumor bed marking but particular mastectomies and soft tissue resections. We are now in a position to effectively guide the radiation oncologist toward the original tumor site, allowing them to minimize radiation to critical structures.
Fig 1. Pre-operative marking of Posterior lateral chest wall recurrence.
Fig 2. Pre-operative MRI demonstrating Left Lateral chest wall involvement of skin and soft tissues including serratus anterior and latissimus dorsi.
Fig 3. Pet CT, Pre Adjuvant Chemo demonstrating LEFT chest wall tumor; a) more cephalad image showing tumor extending between serratus anterior and latissimus dorsi, b) is more caudad image of tumor.
Fig 4. a) Intra-operative view of resected tumor bed, post NAC b), following VeraForm deployment along latissimus and serratus, and c) with overlay marking location of VeraForm.
Fig 5. Immediate Post a) operative photo and b) 5 days post operative.
Fig 6. Adjuvant XRT planning CT simulation with radiopaque VeraForm in place; a) along the serratus, b) along the anterior latissimus.