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


CONCLUSIONS
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.
Vaidya
Jayant S
JS
Department of Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK. j.s.vaidya@dundee.ac.uk
Baum
Michael
M
Tobias
Jeffrey S
JS
Massarut
Samuele
S
Wenz
Frederik
F
Murphy
Olive
O
Hilaris
Basil
B
Houghton
Joan
J
Saunders
Christobel
C
Corica
Tammy
T
Roncadin
Mario
M
Kraus-Tiefenbacher
Uta
U
Melchaert
Frank
F
Keshtgar
Mohammed
M
Sainsbury
Richard
R
Douek
Michael
M
Harrison
Elly
E
Thompson
Alastair
A
Joseph
David
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D010865:Pilot Projects; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage