title: Thyroid tissue: US-guided percutaneous laser thermal ablation.
abstract: OBJECTIVE
  To evaluate in vivo the safety and effectiveness of percutaneous laser thermal ablation (LTA) in the debulking of thyroid lesions.
  
  
  METHODS
  Twenty-five adult patients at poor surgical risk with cold nodules (n = 8), autonomously hyperfunctioning thyroid nodules (n = 16), or anaplastic carcinoma (n = 1) underwent LTA. One to four 21-gauge spinal needles were inserted with ultrasonographic (US) guidance into the thyroid lesions. A 300-microm-diameter quartz optical fiber was advanced through the sheath of the needle. Nd:YAG laser was used with output power of 3-5 W. Side effects, complications, and clinical and hormonal changes were evaluated at the end of LTA and during follow-up. Linear regression analysis was used to investigate the correlation between energy delivered and reduction in nodule volume. Volume of induced necrosis and reduction in nodule volume were assessed with US or computed tomography.
  
  
  RESULTS
  LTA was performed without difficulties in 76 LTA sessions. After treatment with 5 W, two patients experienced mild dysphonia, which resolved after 48 hours and 2 months. Improvement of local compression symptoms was experienced by 12 of 14 (86%) patients. Thyroid-stimulating hormone (TSH) was detectable in five of 16 (31%) patients with hyperfunctioning nodules at 6 months after LTA. Volume of induced necrosis ranged from 0.8 to 3.9 mL per session. Anaplastic carcinoma treated with four fibers yielded 32.0 mL of necrosis. Echo structure and baseline volume did not influence response. Energy load and reduction in nodule volume were significantly correlated (r(2) =.75, P <.001). Mean nodule volume reduction at 6 months in hyperfunctioning nodules was 3.3 mL +/- 2.8 (62% +/- 21.4 [SD]) and in cold nodules was 7.7 mL +/- 7.5 (63% +/- 13.8).
  
  
  CONCLUSIONS
  LTA may be a therapeutic tool for highly selected problems in the treatment of thyroid lesions.
authors.affiliation: Departments of Radiology and Diagnostic Imaging, Ospedale Regina Apostolorum, Via San Francesco 50, 00041 Albano Laziale, Rome, Italy. cmpacel@katamail.com
authors.forename: Claudio Maurizio
authors.initials: CM
authors.lastname: Pacella
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Bizzarri
authors.forename: Stefano
authors.initials: S
authors.lastname: Spiezia
authors.forename: Antonio
authors.initials: A
authors.lastname: Bianchini
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Guglielmi
authors.forename: Anna
authors.initials: A
authors.lastname: Crescenzi
authors.forename: Sara
authors.initials: S
authors.lastname: Pacella
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Toscano
authors.forename: Enrico
authors.initials: E
authors.lastname: Papini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006044:Goiter, Nodular / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000601:surgery*; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000601:surgery*; D013972:Thyrotropin / Q000097:blood; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color; D018084:Ultrasonography, Interventional
chemical_list: D013972:Thyrotropin