Intraoperative Radiation Therapy (IORT) with VeraForm®: Marking for Variability
Radiation therapy choices vary for comprehensive breast cancer treatment. One such option, intraoperative radiation therapy (IORT) is employed in many centers around the country. IORT using the Zeiss® Intrabeam® System has been proven to be non-inferior to External Beam Radiation Therapy (EBRT) in local recurrence and disease-free survival. IORT’s advantage is one treatment during surgery instead of several weeks of EBRT which has obvious benefits for patient convenience, compliance and quality of life. A further important benefit is the lower incidence and severity of toxicities with the Zeiss Intrabeam system as compared to EBRT.
In this time of COVID-19, IORT may offer less exposure to the health care system and therefore less risk of transmission. The ideal patient for IORT is postmenopausal with a relatively small tumor (<3cm), ER positivity and no known nodal involvement or indicators for neoadjuvant chemotherapy. These criteria include most patients that are diagnosed with breast cancer in the US today.
However, consider that up to 20% of patients require post IORT EBRT1 due to features found on final pathology such as positive nodes, a larger tumor than expected, tumor biology surprises, or positive margins found on final pathology requiring re-excision. If a positive node is found on frozen section intraoperatively we may continue with the IORT treatment and use it as a boost.
In our center, VeraForm® has proven to be a safe, effective, user and patient friendly way of marking the tumor bed for EBRT cases and we use it routinely. In discussions with our Radiation Oncology colleagues, we are now using it to mark the tumor bed for IORT cases for the benefit of situations that may require additional radiation in the form of EBRT. In addition, we are marking the area of the tumor bed to aid the breast radiologist who will read follow up mammograms, sonograms and MRIs.
After the lumpectomy is completed, the IORT applicator is placed in the tumor bed and tissue conformance to the applicator is accomplished using a purse-string suture (Fig 1). This is confirmed using intraoperative ultrasound. At the conclusion of the treatment, the applicator is removed and VeraForm is placed to delineate the tumor bed in a 3D manner (Fig 2). Usual oncoplastic techniques are performed to complete the operation.
VeraForm was approved at the Northwell Health system and our hospital was one of the first to adopt it as a regular part of our practice. We have done so for about a year and are very happy with the results. Other technologies have had problems with lack of absorption leaving uncomfortable lumps in the patient which are worrisome on patient self-exam. VeraForm is a soft radiopaque tissue marker filament and cannot be felt by the patient or the physician. It can conform to cavities of any size or shape in contrast to a rigid marker and provides continuous delineation of the target for the radiation oncologist during planning/treatment. It does not affect cosmesis and oncoplastics outcomes can be accomplished with little change in technique.
While many centers utilize IORT in their treatment of breast cancer patients, we believe many are not regularly marking the tumor cavity. We feel the advent of the VeraForm tissue marker makes it an excellent option to combine its application as a routine component of a comprehensive breast treatment program with IORT.
1 Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomised clinical trialBMJ 2020; 370 doi: https://doi.org/10.1136/bmj.m2836 (Published 19 August 2020)Cite this as: BMJ 2020;370:m2836