Thoracic re-irradiation using stereotactic body radiotherapy (SBRT) techniques as first or second course of treatment.
OBJECTIVE
Management for in-field failures after thoracic radiation is poorly defined. We evaluated SBRT as an initial or second course of treatment re-irradiating in a prior high dose region.


METHODS
Thirty-three patients were treated with re-irradiation defined by the prior 30 Gy isodose line. Kaplan-Meier estimates were performed for local (LC), regional (RC), distant control (DC), and overall survival (OS). The plans when available were summed to evaluate doses to critical structures. Patient and treatment variables were analyzed on UVA for the impact on control and survival measures.


RESULTS
Median follow-up was 17 months. Treatment for sequential courses was as follows: (course1:course2) EBRT:SBRT (24 patients), SBRT:SBRT (7 patients), and SBRT:EBRT (3 patients). Median re-irradiation dose and fractionation was 50 Gy and 10 fractions (fx), with a median of 18 months (6-61) between treatments. Median OS was 21 months and 2 year LC 67%, yet LC for >1 fraction was 88% (p=0.006 for single vs. multiple). 10 patients suffered chronic grade 2-3 toxicity (6 chest wall pain, 3 dyspnea, 1 esophagitis) and 1 grade 5 toxicity with aorta-esophageal fistula after 54 Gy in 3 fx for a central tumor with an estimated EQD2 to the aorta of 200 Gy.


CONCLUSIONS
Tumor control can be established with re-irradiation using SBRT techniques for in-field thoracic failures at the cost of manageable toxicity.
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA. Electronic address: jkilburn@wfubmc.edu.
Jeremy M
JM
Kilburn
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
Jeffrey G
JG
Kuremsky
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
A William
AW
Blackstock
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
Michael T
MT
Munley
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
William T
WT
Kearns
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
William H
WH
Hinson
Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, USA.
James F
JF
Lovato
Department of Hematology and Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
Antonius A
AA
Miller
Department of Hematology and Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
William J
WJ
Petty
Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, USA.
James J
JJ
Urbanic
D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D013909:Thorax / Q000528:radiation effects*
Lung; Re-irradiation; SBRT