Stereotactic body radiation therapy for unbiopsied early-stage lung cancer: a multi-institutional analysis

Medically inoperable lung cancer patients often have comorbidities that preclude pathologic diagnosis from being attained. We perform a multi-institutional analysis to determine if unbiopsied early-stage lung carcinoma can be safely and effectively treated with stereotactic body radiation therapy (SBRT).

Thirty-four patients with unbiopsied lung cancer were treated with SBRT at the University of Louisville or University of Virginia. Patients had computed tomography (CT) and positron emission tomography (PET) imaging clinically consistent with lung malignancy. Median SBRT dose was 50 Gy (range, 30 to 55 Gy) in a median of 5 fractions (range, 3 to 10 fractions) with static field SBRT or volumetric modulated arc therapy.

Median follow-up is 16.7 months. Primary tumors had a median longest dimension on the original CT of 1.6 cm (range, 0.5 to 3.3 cm) and posttreatment CT scan of 1.25 cm (range, 0.0 to 4.5 cm) (P=0.025). Median pretreatment standard uptake value on initial PET scan is 4.6 mg/mL (range, 0.0 to 16.2 mg/mL), and at a median of 7.6 months after SBRT, decreased to 2.25 mg/mL (range, 0.0 to 10.9 mg/mL) on posttreatment PET (P=0.002). Crude local control is 97.1%. The estimated 2-year regional control is 80%, distant control 85%, and overall survival 85%. There were no grade 3 or greater acute toxicities and only 3 grade 3 chronic treatment-related toxicitities.

In medically inoperable patients with unbiopsied lung cancer, local control can be achieved with minimal toxicity with the use of SBRT. The use of SBRT for unbiopsied early-stage lung cancer patients should be performed in a multidisciplinary setting and after detailed discussion with the patient about the risks and benefits of SBRT.