CyberKnife radiosurgery for stage I lung cancer: results at 36 months.

PURPOSE: The aims of this study were to determine if image-guided robotic stereotactic radiosurgery by CyberKnife Radiosurgery System using ablative radiation doses achieves acceptable local control in medically inoperable patients with early non-small-cell lung cancer (NSCLC) and to evaluate disease-free survival, toxicity, and failure. CyberKnife can deliver the prescribed dose by using many different angles converging on the target, with real-time target tracking through a combined orthogonal radiograph imaging and optic motion tracking system (Synchrony). MATERIALS AND METHODS: A review of treatment details and outcomes for 59 patients, ranging in age from 51 years to 96 years, with 61 tumors with histologically proven cancers treated by image-guided robotic stereotactic radiosurgery at the CyberKnife Center of Miami between March 2004 and March 2007 is presented. Target localization and respiratory movement compensation were accomplished using a single fiducial marker placed within the tumor, and the X-Sight and Synchrony systems. Total doses ranged from 15 Gy to 67.5 Gy delivered in 1-5 fractions with an equivalent dose range of 24-110 Gy normalized treatment dose in 2 Gy fractions (alpha/beta = 20 Gy). RESULTS: Four patients with stage 1A NSCLC and 2 patients with stage 1B NSCLC had persistent or recurrent disease. All patients tolerated the radiosurgery well, fatigue being the main side effect. Of the 59 patients treated, 51 (86%) were still alive at 1-33-month follow-up. Eight patients have died, 2 of diseases other than cancer progression. CONCLUSION: The results indicate that the delivery of precisely targeted ablative radiation doses with surgical precision to limited treatment volumes of lung tumors in a hypofractionated fashion is feasible and safe. Image-guided robotic stereotactic radiosurgery of lung tumors with CyberKnife(R) achieves excellent rates of local disease control with limited toxicity to surrounding tissues and, in many cases, might be curative for patients for whom surgery is not an option.

Treatment of early non-small cell lung cancer, stage IA, by image-guided robotic stereotactic radioablation--CyberKnife.

OBJECTIVE: To evaluate the efficacy of using image-guided robotic stereotactic radioablation as an alternative treatment modality for patients with surgically resectable, but medically inoperable, T1 N0 M0, stage IA non-small cell lung cancer. METHODS: Between January 2004 and May 2006, 19 patients, 11 women and 8 men ranging in age from 52 to 88 years, with stage IA non-small cell lung cancer were treated. Tumor volume ranged from 1.7 to 13 mL. Total doses ranged from 24 to 60 Gy delivered in 3 fractions. Eleven patients received 60 Gy. Real-time target localization was accomplished by radiographic detection of fiducial marker(s) implanted within the tumor combined with respiratory motion tracking. RESULTS: All patients tolerated radioablation well with fatigue as the main side effect. Fourteen patients are alive from 1 to 25 months posttreatment. Four patients died: 2 of comorbid disease and 2 of cancer progression (status post 60 and 55.5 Gy). Three patients developed grade I radiation pneumonitis. Two patients have stable disease. In 3 patients, cancer recurred in the planning treatment volume: in 2 patients after treatment with 60 Gy and in 1 patient after treatment with 55.5 Gy. One patient had local control in the target volume but developed metastasis to the ipsilateral hilum. Nine patients had a complete response and show no evidence of disease. CONCLUSIONS: In our early experience, stereotactic radioablation using the CyberKnife system appears to be a safe, minimally invasive, and effective modality for treating early stage lung cancer in patients with medically inoperable disease. Dose escalation and/or increasing the treatment volumes, with the aid of the high conformality of this technique, may help to achieve further improvements in these promising results.