title: Percutaneous radiofrequency ablation for the hepatocellular carcinoma abutting the diaphragm: assessment of safety and therapeutic efficacy.
abstract: OBJECTIVE
  To assess the safety and therapeutic efficacy of a percutaneous radiofrequency (RF) ablation for the hepatocellular carcinoma (HCC) abutting the diaphragm.
  
  
  METHODS
  We retrospectively assessed 80 patients who underwent a percutaneous RF ablation for a single nodular (< 4 cm) HCC over the last four years. Each patient underwent an ultrasound-guided RF ablation using internally cooled electrodes for the first-line treatment. We divided patients into two subgroups based on whether the index tumor was abutting (less than 5 mm) the diaphragm or not: group A (abutting; n = 31) versus group B (non-abutting; n = 49). We compared the two subgroups for complications and therapeutic efficacy using image and the review of medical records. The statistical assessment included an independent t-test, Fisher's exact test, and chi-square test.
  
  
  RESULTS
  The assessment of the diaphragmatic swelling at CT immediately following the procedure was more severe in group A than group B (mean thickness change:1.44 vs. 0.46 mm, p = 0.00). Further, right shoulder pain was more common in group A than B (p = 0.01). Although minor complications (hemothorax 1 case, pleural effusion 1 case) were noted only in group A, no major thoracic complication occurred in either group. The technical success rate was lower in group A than group B (84% vs. 98%, p = 0.03). As well, the primary and secondary technique effectiveness rates in group A and group B were 90% versus 98% (p = 0.29) and 79% versus 91% (p = 0.25), respectively. The local tumor progression rate was higher in group A than in group B (29% vs. 6%, p = 0.02).
  
  
  CONCLUSIONS
  We found that the percutaneous RF ablation for the HCC abutting the diaphragm is a safe procedure without major complications. However, it is less effective with regard to technical success and local tumor control.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Kang
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002056:Burns / Q000209:etiology; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D003964:Diaphragm / Q000293:injuries / Q000473:pathology; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000601:surgery*; D055370:Lung Injury / Q000209:etiology; D008297:Male; D008875:Middle Aged; D020069:Shoulder Pain / Q000209:etiology; D016896:Treatment Outcome; D055815:Young Adult