title: CT-guided interstitial single-fraction brachytherapy of lung tumors: phase I results of a novel technique.
abstract: OBJECTIVE
  To assess the safety of CT-guided brachytherapy of lung malignancies and to evaluate the initial therapeutic response.
  
  
  METHODS
  Fifteen patients with 30 lung malignancies were included in this prospective phase I trial (metastases, 28; non-small cell lung cancers, 2). Pre-interventionally two patients had a vital capacity of < 80% (39% and 63%). These two patients, and one other, had FEV1 values of < 80% predicted (17%, 48%, and 64%). Tumors with a maximum diameter of 4 cm were treated with a single brachytherapy catheter that was positioned under CT-fluoroscopy. In two tumors with tumor diameters of 5.5 and 6.5 cm, two applicators were used. In one patient with an 11-cm irregularly shaped tumor, nine catheters were inserted. Treatment planning for 192Ir brachytherapy was performed using three-dimensional CT data that were acquired after percutaneous applicator positioning. All procedures were performed under local anesthesia. A follow-up CT was performed 6 weeks later and every 3 months pos-tintervention.
  
  
  RESULTS
  The mean diameter of the 30 lung tumors was 2 cm (range, 0.6 to 11 cm; median diameter, 1.5 cm). The minimal dose within the tumor margin was 20 Gy in all 30 tumors treated. Except for nausea in one patient and focal hemorrhage detected on CT in two patients, no acute adverse events were recorded. One patient developed an abscess at the previous tumor location 9 months after treatment, which proved to be a local tumor recurrence. The median follow-up period was 5+ months with a local tumor control of 97%.
  
  
  CONCLUSIONS
  The novel technique of CT-guided interstitial brachytherapy was safe for the treatment of lung tumors and yielded a very low complication rate. The initial data on therapeutic response are promising.
authors.affiliation: Klinik für Strahlenheilkunde, Charité, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany. jens.ricke@charite.de
authors.forename: Jens
authors.initials: J
authors.lastname: Ricke
authors.forename: Peter
authors.initials: P
authors.lastname: Wust
authors.forename: Gero
authors.initials: G
authors.lastname: Wieners
authors.forename: Susanne
authors.initials: S
authors.lastname: Hengst
authors.forename: Maciej
authors.initials: M
authors.lastname: Pech
authors.forename: Enrique
authors.initials: E
authors.lastname: Lopez Hänninen
authors.forename: Roland
authors.initials: R
authors.lastname: Felix
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010166:Palliative Care / Q000379:methods*; D011336:Probability; D011446:Prospective Studies; D011788:Quality of Life; D015642:Radiology, Interventional / Q000379:methods*; D011879:Radiotherapy Dosage; D018570:Risk Assessment; D016019:Survival Analysis; D019452:Terminally Ill; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome