Stereotactic radiotherapy for lung and liver tumors using a body cast system: setup accuracy and preliminary clinical...

To evaluate the feasibility and treatment outcomes of stereotactic radiotherapy (SRT) using a newly developed simple body cast system for lung and liver tumors.

From April 2003 to July 2004, 20 patients were treated with SRT at the Kyushu University Hospital. Thirteen patients had primary lung cancer, 5 had metastatic lung cancer, and 2 had hepatocellular carcinoma. All patients were fixed with a thermoplastic body cast combined with a vacuum pillow, arm and leg support, and a carbon plate. SRT was given in 5-8 fields with an isocenter dose of 48-60 Gy in 4-10 fractions. Target verification was performed by computed tomography (CT) during the first session, and by anterior-posterior (A-P) and lateral portal images during the second and subsequent sessions.

The average setup errors and deviation in the first treatment session were 1.4 +/- 1.2, 1.1 +/- 1.0, and 3.3 +/- 2.8 mm in the lateral, A-P, and cranio-caudal (C-C) directions, respectively. The setup errors in the second and subsequent sessions were 2.4 +/- 0.5, 1.4 +/- 1.8, and 3.7 +/- 2.6 mm in the lateral, A-P, and C-C directions, respectively. The patient's movement during a treatment session was within 5 mm in any direction. Despite the short follow-up periods (1-15 months), complete response was shown in 4 lesions, and partial response was shown in 15 lesions. Neither local progression nor serious complication was observed in any patient.

SRT using our body cast system was a safe and reliable treatment method for extracranial tumors.