title: Clinical outcomes of stereotactic radiotherapy for stage I non-small cell lung cancer using a novel irradiation technique: patient self-controlled breath-hold and beam switching using a combination of linear accelerator and CT scanner.
abstract: We have developed a novel irradiation technique for lung cancer that combines a linear accelerator and CT scanner with patient-controlled breath-hold and radiation beam switching. We applied this technique to stereotactic three-dimensional (3D) conformal radiotherapy for stage I non-small cell lung cancer (NSCLC) and evaluated the primary therapeutic outcomes. A total of 35 patients with stage I (15 IA, 20 IB) primary NSCLC (20 adeno, 13 squamous cell, and 2 others) were treated with this technique. Patients ranged from 65 to 92 years old (median, 78 years). Twenty-three (66%) patients were medically inoperable due to mainly chronic pulmonary disease or high age. Three-dimensional treatment plans were made using 10 different non-coplanar dynamic arcs. The total dose of 60 Gy was delivered in 10 fractions (over 5-8 days) at the minimum dose point in the planning target volume (PTV) using a 6 MV X-ray. After adjusting the isocenter of the PTV to the planned position by a unit comprising CT and linear accelerator, irradiation was performed under patient-controlled breath-hold and radiation beam switching. All patients completed the treatment course without complaint. Complete response (CR) and partial response (PR) rates were 8/35 (23%) and 25/35 (71%), respectively. Pulmonary complications of National Cancer Institute-Common Toxicity Criteria grade >2 were noted in three (9%) patients. During follow-up (range, 6-30 months; median, 13 months), two (6%) patients developed local progression and five (14%) developed distant or regional lymph node metastases. Two-year overall survival rates for total patients and medically operable patients were 58 and 83%, respectively. In conclusion, this new irradiation technique, utilizing patient-controlled radiation beam switching under self-breath-hold after precise alignment of the isocenter, allows safe high-dose stereotactic radiotherapy with sufficient margins around the CTV and reduced treatment times. Based on the initial results, excellent local control with minimal complications is expected for stage I NSCLC.
authors.affiliation: Department of Radiation Oncology, Yamanashi Medical University, 1110 Shimokato Tamaho-cho, Nakakoma-gun, Yamanashi 409-3898, Japan. honishi@res.yamanashi-med.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Onishi
authors.forename: Kengo
authors.initials: K
authors.lastname: Kuriyama
authors.forename: Takafumi
authors.initials: T
authors.lastname: Komiyama
authors.forename: Shiho
authors.initials: S
authors.lastname: Tanaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Sano
authors.forename: Kan
authors.initials: K
authors.lastname: Marino
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikenaga
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
authors.forename: Minoru
authors.initials: M
authors.lastname: Uematsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D009367:Neoplasm Staging; D010315:Particle Accelerators; D016634:Radiosurgery / Q000379:methods*; D012119:Respiration; D012648:Self Care; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome