title: Percutaneous laser ablation in the treatment of hepatocellular carcinoma with small tumors: analysis of factors affecting the achievement of tumor necrosis.
abstract: OBJECTIVE
  To identify the factors that affect the achievement of tumor necrosis with percutaneous laser ablation (PLA) in patients with hepatocellular carcinoma (HCC) and tumor size no larger than 4.0 cm.
  
  
  METHODS
  Ultrasound-guided biopsy results were retrospectively studied in 99 lesions (range, 0.5-4.0 cm; mean, 2.7 cm) from 82 patients (44 men, 38 women; age range, 50-80 years; median, 68 y) who had undergone PLA.
  
  
  RESULTS
  Complete tumor ablation was obtained in 90 lesions (90.9%). Of the nine cases in which complete tumor necrosis was not achieved, six had tumors located in sites that did not allow the optimal placement of fibers, and five of these had a tumor diameter greater than 3 cm. Early discontinuation of PLA as a result of decompensation of liver cirrhosis was the reason for not achieving a complete tumor ablation in three other cases. There was a clear relationship between the energy delivered and the volume of necrosis achieved (r = 0.56; P < .001) regardless of the initial size of HCC tumors. The number of illuminations required, and consequently the amount of energy delivered, was also affected by tumor location. In fact, lesions adjacent to large vessels (> or = 3 mm) required a greater number of illuminations than the other lesions to achieve complete ablation (2.9 +/- 1.4 vs 2.3 +/- 0.9; P = .043). The eight cases with undifferentiated histology required more illuminations than the cases with other histologic types (3.4 +/- 0.9 vs 2.2 +/- 0.9; P < .001). However, these cases were located in sites that did not allow the optimal placement of fibers, therefore requiring multiple treatments.
  
  
  CONCLUSIONS
  PLA is a highly effective treatment in HCC with a tumor size of 4.0 cm or smaller. In this setting, two variables, tumor size and tumor location, affect the achievement of complete tumor ablation and the number of treatments required to obtain tumor necrosis.
authors.affiliation: Department of Diagnostic Imaging and Interventional Radiology, Ospedale Regina Apostolorum, Rome, Italy. claudiomaurizio.pacella@fastwebnet.it
authors.forename: Claudio Maurizio
authors.initials: CM
authors.lastname: Pacella
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Bizzarri
authors.forename: Giampiero
authors.initials: G
authors.lastname: Francica
authors.forename: Antonio
authors.initials: A
authors.lastname: Bianchini
authors.forename: Stefano
authors.initials: S
authors.lastname: De Nuntis
authors.forename: Sara
authors.initials: S
authors.lastname: Pacella
authors.forename: Anna
authors.initials: A
authors.lastname: Crescenzi
authors.forename: Silvia
authors.initials: S
authors.lastname: Taccogna
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Forlini
authors.forename: Zaccaria
authors.initials: Z
authors.lastname: Rossi
authors.forename: John
authors.initials: J
authors.lastname: Osborn
authors.forename: Roberto
authors.initials: R
authors.lastname: Stasi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D006528:Carcinoma, Hepatocellular / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053685:Laser Therapy; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000453:epidemiology; D009367:Neoplasm Staging; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden