title: Squamous cell carcinoma of the external auditory canal: two cases treated with high dose rate 192Ir remote afterloading system (RALS).
abstract: We report two cases of early-stage external auditory canal cancer treated by intracavitary irradiation with a high dose rate (HDR) 192Ir remote afterloading system (RALS) for preoperative treatment. A 6-Fr catheter for the HDR 192Ir remote afterloader, fixed by a plastic earplug, was inserted into the external auditory canal in two cases (case 1, T2N0M0; case 2, T1N0M0). The total intracavitary radiation dosages were 50 Gy (10 Gy/2 Fr/wk for 5 wks) for case 1, and 42 Gy (15 Gy/5 Fr/wk for 3 wks) for case 2. No external irradiation was given in either case. Surgical resection was performed in both cases, three to four weeks after irradiation. Histopathological examination confirmed the post-irradiation changes of necrosis, hyalinosis, and calcification, although vivid cancer cells remained. In preoperative irradiation of external auditory cancer, this method, although limited to treating early-stage cancers, may be a modality of choice for its efficacy and less severe side effects.
authors.affiliation: Department of Radiology, Shimane Medical University, Izumo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Uchida
authors.forename: S
authors.initials: S
authors.lastname: Kuroda
authors.forename: T
authors.initials: T
authors.lastname: Kushima
authors.forename: M
authors.initials: M
authors.lastname: Moriyama
authors.forename: K
authors.initials: K
authors.lastname: Sugimura
authors.forename: H
authors.initials: H
authors.lastname: Kawauchi
authors.forename: R
authors.initials: R
authors.lastname: Shirakawa
mesh_terms: D001918:Brachytherapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D004424:Ear Canal; D004428:Ear Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D008875:Middle Aged; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed
chemical_list: D007496:Iridium Radioisotopes