title: Radiation therapy for roentogenographically occult lung cancer by external beam irradiation and endobronchial high dose rate brachytherapy.
abstract: OBJECTIVE
  We investigated the clinical usefulness of radiation therapy by external beam irradiation and endobronchial brachytherapy for the treatment of roentogenographically occult lung cancer.
  
  
  METHODS
  From 1995 to 1996, five patients were treated with radiation therapy. We analyzed their treatment outcomes. The follow-up period varied from 3.0 to 3.8 years or until death. External beam radiation (40 Gy/20 fractions/4 weeks) was delivered to the tumor site alone, and not prophylactically given to the mediastinum. Endobronchial brachytherapy using high dose rate iridium (Ir)-192 was concurrently administered principally to a total dose of 18 Gy on the bronchial mucosa in three weekly fractions of 6 Gy each.
  
  
  RESULTS
  Complete remission was obtained in all patients. Two patients died of intercurrent diseases at 12 and 21 months without any evidence of recurrence. The disease has been also controlled in the other three cases. With the above doses, three small tumors < 1 cm were controlled without adverse effect. In two tumors, the dose reference points were set 2-7 mm beneath the mucosa, and larger doses were administered by brachytherapy. An applicator acting as a spacer was not used in these cases. The tumors were controlled, although the irradiated bronchi showed severe stenosis in 6 months following the treatment. However, the patients were asymptomatic and did not need further intervention.
  
  
  CONCLUSIONS
  External beam irradiation combined with endobronchial brachytherapy was useful for the treatment of roentogenographically occult lung cancer as an alternative to surgery. Further investigation is needed to determine the optimal doses of radiation therapy.
authors.affiliation: Division of Radiation Therapy, Tochigi Cancer Center, Utsunomiya, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Furuta
authors.forename: I
authors.initials: I
authors.lastname: Tsukiyama
authors.forename: T
authors.initials: T
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Katano
authors.forename: K
authors.initials: K
authors.lastname: Yokoi
authors.forename: M
authors.initials: M
authors.lastname: Sawafuji
authors.forename: K
authors.initials: K
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Tominaga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D001980:Bronchi / Q000528:radiation effects; D001999:Bronchoscopy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D005336:Fiber Optic Technology; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D009367:Neoplasm Staging; D013902:Radiography, Thoracic; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome