title: Radiation Pneumonitis Changes over Time after Stereotactic Body Radiation Therapy for Lung Tumors: Post-treatment Cavity (Sunny-side-up Egg-like) Changes.
abstract: Stereotactic body radiation therapy (SBRT) is a viable treatment option for stage I non-small cell lung carcinoma (NSCLC) in non-surgical candidates. Although treatment with a 100 Gy biological effective dose is considered to carry a low risk of local recurrence, only a few reports have focused on changes in tumors or surrounding intact portions of the lung after SBRT. Such changes are assessed using diagnostic imaging specifically for radiation pneumonitis, which can be difficult to distinguish from local tumor recurrence. Cavity changes after SBRT observed around the tumor within the irradiated field resemble an egg, fried with the yolk facing upward, and are thus referred to as 'sunny-side-up egg-like' changes. They have the appearance of a residual tumor in the center. This study aimed to evaluate patients with post-treatment cavity changes after SBRT for stage I NSCLC.
  
  
  
  Cavity changes were observed in four cases. Tumors were irradiated with a 6-MV X-ray using 10 fixed ports. The single dose was 12 Gy, the total dose 48 Gy.
  
  
  
  The time until the appearance of cavity changes ranged from 4 to 9 months (median=6 months). The cavity changes disappeared in 12-20 months (median=16 months).
  
  
  
  Cavity changes (sunny-side-up egg-like) in the lungs may develop after SBRT for stage I NSCLC.
authors: Department of Radiology, Nihon University School of Medicine, Tokyo, Japan maebayashi.toshiya@nihon-u.ac.jp.
authors: Toshiya
authors: T
authors: Maebayashi
authors: Department of Radiology, Nihon University School of Medicine, Tokyo, Japan.
authors: Naoya
authors: N
authors: Ishibashi
authors: Department of Radiology, Nihon University School of Medicine, Tokyo, Japan.
authors: Takuya
authors: T
authors: Aizawa
authors: Department of Radiology, Nihon University School of Medicine, Tokyo, Japan.
authors: Masakuni
authors: M
authors: Sakaguchi
authors: Radiology Clinic, Sonoda Medical Corporation, Tokyo, Japan.
authors: Tsutomu
authors: T
authors: Sato
authors: Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan.
authors: Jiro
authors: J
authors: Kawamori
authors: Department of Radiation Oncology, Kawasaki Saiwai Hospital, Kawasaki, Japan.
authors: Yoshiaki
authors: Y
authors: Tanaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D017564:Radiation Pneumonitis / Q000473:pathology*; D016634:Radiosurgery
keywords: Radiation pneumonitis; cavity changes; lung cancer; non-small cell lung cancer; radiation therapy; stereotactic body radiation therapy