Clinical Outcomes of Stereotactic Body Radiotherapy for Small Lung Lesions Clinically Diagnosed as Primary Lung Cancer on Radiologic Examination
Received 21 August 2008; received in revised form 17 November 2008; accepted 20 November 2008. published online 23 February 2009.
Purpose
Image-guided biopsy occasionally fails to diagnose small lung lesions, which are highly suggestive of primary lung cancer. The aim of the present study was to evaluate the outcome of stereotactic body radiotherapy (SBRT) for small lung lesions that were clinically diagnosed as primary lung cancer without pathologic confirmation.
Methods and Materials
A total of 115 patients were treated with SBRT in 12 institutions. Tumor size ranged from 5 to 45 mm in diameter, with a median of 20 mm.
Results
The 3-year and 5-year overall survival rates for patients with a tumor size ≤20 mm in diameter (n = 58) were both 89.8%, compared with 60.7% and 53.1% for patients with tumors >20 mm (n = 57) (p <0.0005), respectively. Local progression occurred in 2 patients (3.4%) with a tumor size ≤20 mm and in 3 patients (5.3%) with tumors >20 mm. Among the patients with a tumor size ≤20 mm, Grade 2 pulmonary complications were observed in 2 (3.4%), but no Grade 3 to 5 toxicity was observed. In patients with a tumor size >20 mm, Grades 2, 3, and 5 toxicity were observed in 5 patients (8.8%), 3 patients (5.3%), and 1 patient (1.8%), respectively.
Conclusion
In patients with a tumor ≤20 mm in diameter, SBRT was reasonably safe in this retrospective study. The clinical implications of the high local control rate depend on the accuracy of clinical/radiologic diagnosis for small lung lesions and are to be carefully evaluated in a prospective study.
∗Hokkaido University Department of Radiology, Sapporo, Japan
†Ofuna Central Hospital, Department of Radiology, Ofuna, Japan
‡Yamanashi University Department of Radiology, Kofu, Japan
§Hiroshima University Department of Radiology, Hiroshima, Japan
‖Kagawa University Department of Radiology, Takamatsu, Japan
¶Tokyo Metropolitan Komagome Hospital, Department of Radiology, Tokyo, Japan
#Kitami Red Cross Hospital, Department of Radiology, Kitami, Japan
∗∗Sapporo Medical University Department of Radiology, Sapporo, Japan
††Hokkaido University First Department of Internal Medicine, Sapporo, Japan
Reprint requests to: Hiroki Shirato, M.D., Ph.D., Department of Radiology, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan. Tel: +81-11-706-5977; Fax: +81-11-706-7876
ABSTRACT