International Journal of Radiation Oncology*Biology*Physics
Clinical investigationBreastTargeted intraoperative radiotherapy (TARGIT) yields very low recurrence rates when given as a boost
Introduction
Early local recurrences after breast-conserving surgery and postoperative radiotherapy for breast cancer most commonly occur in the vicinity of the primary tumor bed (1). A radiotherapy boost to the tumor bed is therefore part of standard treatment. However, accurate targeting of this boost can be difficult because of deformation and positional change of the postoperative breast, particularly because there is often a considerable delay between surgery and radiotherapy planning. A “geographical miss” occurs in 50–80% of patients (2, 3, 4) and this may contribute toward a proportion of local recurrences. Modern radiotherapy planning by computed tomography simulation, in which surgical clips are outlined, may be able to reduce this. However, a much simpler and direct method may be to use intraoperative radiotherapy.
We developed a novel technique of delivering intraoperative therapeutic irradiation that we call targeted intraoperative radiotherapy (TARGIT) (5, 6). With this technique, using the Intrabeam system, the target tissue—namely, the tumor bed—is wrapped around or conformed to the radiotherapy source, which delivers radiotherapy from within the breast, usually under the same anesthetic as the primary surgery. The procedure can be performed in a standard operating theater and adds 20 to 40 min to the operation time.
We are currently testing whether partial-breast irradiation, using this technique in selected patients, can replace conventional whole-breast external-beam radiotherapy (EBRT) in a multicenter randomized trial (7, 8). Centers participating in this trial initially treated a series of pilot cases to test the feasibility and safety of using the new technique of intraoperative radiotherapy supplemented by standard EBRT in patients with a high risk of local recurrence. This article describes the outcomes in relation to local recurrence, among the 301 consecutive patients in whom intraoperative radiotherapy was used as a tumor bed boost.
Section snippets
Methods and materials
The study protocol was approved by the local ethics committee in each center. Patients of any age suitable for breast-conserving surgery were approached and consented to participate in the pilot studies at each of the five centers. Tumors were unifocal on mammography up to 4 cm in diameter. There was no restriction by tumor type, tumor grade, receptor status, or axillary lymph node involvement. Each patient had her breast-conserving surgery as per local protocol—typically a wide local excision
Results
Between July 1998 and Aug 2005, 321 patients participated in this pilot study; 20 patients were excluded. One patient had multiple diffuse margin involvement and declined further surgery, 1 patient had bilateral prophylactic mastectomy (at her request), and 18 patients had further surgery for involved margins: 13 mastectomy and 5 re-excision. Thus, the total evaluable patients included in this study are 301. One patient had bilateral cancers treated, making the total number of cancers equal to
Discussion
This study demonstrates that radiotherapy targeted to the tumor bed, when it is most accessible at the time of surgery for the cancer, is associated with a low rate of local disease recurrence: 2.6% in actuarial terms at 5 years. The patient population in this series is representative of patients suitable for breast-conserving therapy (with T1 = 78% and T2 = 21%, Gr1 = 22%, Gr2 = 48.8%, Gr3 = 28.7%, and 29% node-positive). Approximately one-third (98/301) of these patients were younger than 51
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Biological response in breast cancer patients using intraoperative radiotherapy
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2018, Reports of Practical Oncology and RadiotherapyCitation Excerpt :The targeted intraoperative radiotherapy (TARGIT) trial verified the value of kilovoltage photon-based IORT for APBI.13 The advantage of the method is that it can be followed with WBRT.14,15 The TARGIT trial protocol recommends using WBRT after IORT in cases of extensive intraductal component, resection margins <1 mm, and lobular cancer.
Breastdosimetry of <sup>99m</sup>Tc-balloon in complementary radiotherapy
2016, Applied Radiation and IsotopesRisk factors for seroma evacuation in breast cancer patients treated with intraoperative radiotherapy
2016, Reports of Practical Oncology and RadiotherapyCitation Excerpt :The technique and its clinical application were described by Vaidya.12,13 IORT given as a boost is an effective option for breast-conserving treatment.14 Data gathered in the Targeted Intraoperative radiotherapy (TARGIT) and Intraoperative radiotherapy with electrons (ELIOT) trials support the idea that some patients with breast cancer can be offered APBI as a sole radiation modality in BCT.15–17
Intraoperative Irradiation
2015, Clinical Radiation Oncology
J.S.V., M.B., and J.S.T. conceived the study.
J.S.V., M.B., J.S.T., S.M., M.R., B.H., U.K., F.W., D.J., C.S., A.M.T., J.A.D. recruited and treated patients. J.S.V., M.B., J.S.T., S.M, M.R., B.H., U.K., F.W., D.J., C.S., A.M.T., J.A.D., E.H., and J.H. collected the data.
M.K., R.S., M.D., and F.M. were involved in later follow-up care.
J.S.V., O.M., S.M., U.K.T., T.C., and B.H. analyzed the data.
J.S.V. and S.M. wrote the first draft and all other authors contributed to the final manuscript.