Targeted intraoperative radiotherapy (TARGIT) yields very low recurrence rates when given as a boost

Received 11 May 2006; received in revised form 21 July 2006; accepted 27 July 2006. published online 02 November 2006.

Purpose: Patients undergoing breast-conserving surgery were offered boost radiotherapy with targeted intraoperative radiotherapy (TARGIT) using the Intrabeam system to test the feasibility, safety, and efficacy of the new approach.

Methods and Materials: We treated 302 cancers in 301 unselected patients. This was not a low-risk group. One-third of patients (98/301) were younger than 51 years of age. More than half of the tumors (172, 57%) were between 1 cm and 2 cm, and one-fifth (62, 21%) were >2 cm; 29% (86) had a Grade 3 tumor and, in 29% (87), axillary lymph nodes contained metastasis. After primary surgery, 20 Gy was delivered intraoperatively to the surface of the tumor bed, followed by external-beam radiotherapy (EBRT), but excluding the usual boost.

Results: The treatment was well tolerated. The follow-up ranged from 3 to 80 months (164 and 90 patients completed 2 and 3 years follow-up, respectively). Four patients (1.3%) had local recurrence. The Kaplan-Meier estimate of local recurrence is 2.6% (SE = 1.7) at 5 years. This compares favorably with the 4.3% recurrence rate in boosted patients from the EORTC boost study, in which only 8.1% patients were node-positive, as opposed to 29% in our series.

Conclusion: Targeted intraoperative radiotherapy combined with EBRT results in a low local recurrence rate. This could be attributed to both accurate targeting and timeliness of the treatment. These data support the need for a randomized trial to test whether the TARGIT boost is superior to conventional external boost, especially in high-risk women.

Keywords: Breast cancer, Targeted intraoperative radiotherapy (TARGIT), Boost, Recurrence rate, Breast-conserving surgery

⁎ Department of Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom

† Department of Surgery and Radiation Oncology, University College London, London, United Kingdom

‡ Department of Surgery and Radiation Oncology, Centro di Riferimento Oncologico (CRO), Aviano, Italy

§ Mannheim Medical Center, University of Mannheim, Mannheim, Germany

¶ Department of Radiation Oncology, Sir Charles Gairdner Hospital and School of Surgery and Pathology, University of Western Australia, Perth, Australia

∥ Department of Radiation Oncology, Our Lady of Mercy, New York Medical College, New York, NY

Reprint requests to: Jayant S. Vaidya, M.B.B.S., M.S., D.N.B., F.R.C.S., Ph.D., F.R.C.S. (GEN), Surgery and Molecular Oncology, Level 6, Ninewells Hospital and Medical School, University of Dundee, DD12UY, Dundee, Scotland, United Kingdom. Tel: (+44) 138-266-0111; Fax: (+44) 138-249-6363

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.

PII: S0360-3016(06)02754-4

doi:10.1016/j.ijrobp.2006.07.1378

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