title: Prophylactic embolization of renal angiomyolipomas: evaluation of therapeutic response using CT 3D volume calculation and density histograms.
abstract: OBJECTIVE
  To evaluate the efficacy and tolerance of prophylactic embolization of angiomyolipomas (AMLs) and to analyze the therapeutic response by using three-dimensional 3D volume calculation and 3D quantification of fatty and angiomyogenic components during computed tomography (CT) follow-up.
  
  
  METHODS
  Over a 51-month period, 30 patients with 34 AMLs (mean diameter, 82 mm ± 37; range, 30-173 mm) underwent 37 prophylactic embolization procedures. The protocol included supraselective arterial embolization with a combination of absolute alcohol, microparticles, and coils. Mean clinical and imaging follow-up were 20.5 and 14.5 months, respectively. The 3D volume calculation and density histograms were retrospectively analyzed for treatment evaluation.
  
  
  RESULTS
  Four technical failures were observed (11%), with one successful secondary reattempt, resulting in 31 AMLs (91.2%) being embolized. Thirty (88.2%) had CT follow-up and were included in the analysis. Embolization was complete after a single procedure for 25 AMLs (83%) and required two procedures in two cases. Three AMLs had incomplete embolization and were scheduled for a second procedure. Mean volume reductions were 43% ± 32 for AMLs followed for 1-6 months after embolization and 81% ± 19 for the 12 AMLs followed for more than 1 year. The volume reduction after embolization was significantly correlated with the AML initial composition, with fat-rich AMLs showing a much smaller reduction of size than predominantly angiomyomatous AMLs (P < .05).
  
  
  CONCLUSIONS
  Prophylactic embolization allows significant reduction of AML volume with a high success rate. Three-dimensional CT volume and density histogram calculations suggest that it is especially effective on angiomyogenic components and fat-poor AMLs.
authors.affiliation: Adult Radiology Service, Hôpital Necker Enfants Malades, 161 rue de Sèvres, 75743 Paris 15, France. op@cegetel.net
authors.forename: Olivier
authors.initials: O
authors.lastname: Planché
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Correas
authors.forename: Benoît
authors.initials: B
authors.lastname: Mader
authors.forename: Dominique
authors.initials: D
authors.lastname: Joly
authors.forename: Arnaud
authors.initials: A
authors.lastname: Méjean
authors.forename: Olivier
authors.initials: O
authors.lastname: Hélénon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D004621:Embolization, Therapeutic / Q000009:adverse effects; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007680:Kidney Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010297:Paris; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult