Radiation lobectomy: preliminary findings of hepatic volumetric response to lobar yttrium-90 radioembolization.
OBJECTIVE
To describe volumetric changes of "radiation lobectomy," a manifestation of hepatic parenchymal response to lobar (90)Y microsphere radioembolization.


METHODS
Twenty patients exhibiting this phenomenon were identified. Pre- and posttreatment absolute right and left hepatic lobar volume (HLV), relative HLV (rHLV = HLV/total liver volume), and degree of lobar atrophy (DA) or hypertrophy (DH) (DA or DH = |posttreatment rHLV - pretreatment rHLV|) were determined. Laboratory toxicities, tumor response, and patient survival were also assessed.


RESULTS
Twenty patients with primary (HCC, n = 17; peripheral cholangiocarcinoma, n = 3) liver malignancies demonstrated findings of radiation lobectomy. Initial absolute right and left HLV was 955 cm(3) (range 644-1,842 cm(3), rHLV = 57%) and 719 cm(3) (range 328-1,387 cm(3), rHLV = 43%), respectively. Following (90)Y, absolute right HLV decreased to 460 cm(3) (range 185-948 cm(3), 52% reduction, rHLV = 31%, DA = 26%, P < 0.0001), while absolute left HLV increased to 1,004 cm(3) (range 560-1,558 cm(3), 40% increase, rHLV = 69%, DH = 26%, P < 0.0001). No grade 3 or 4 bilirubin toxicities were encountered. Tumor response ranged from 55% to 70% by size criteria. Forty-six percent 5-year survival was achieved in HCC patients.


CONCLUSIONS
Radiation lobectomy following (90)Y radioembolization of right lobe tumors manifests extensive contralateral lobar hypertrophy, high response rates, and prolonged survival. This phenomenon was noted in 6.4% (20/315) of the entire cohort and 19.8% (20/101) of patients with unilobar right lobe tumors. Further investigation is necessary to determine contributing factors that may predict this effect.
Gaba
Ron C
RC
Department of Radiology, University of Illinois at Chicago, USA.
Lewandowski
Robert J
RJ
Kulik
Laura M
LM
Riaz
Ahsun
A
Ibrahim
Saad M
SM
Mulcahy
Mary F
MF
Ryu
Robert K
RK
Sato
Kent T
KT
Gates
Vanessa
V
Abecassis
Michael M
MM
Omary
Reed A
RA
Baker
Talia B
TB
Salem
Riad
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D001653:Bile Ducts, Intrahepatic; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000532:radiotherapy*; D018281:Cholangiocarcinoma / Q000473:pathology / Q000532:radiotherapy*; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology* / Q000528:radiation effects; D008113:Liver Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D009929:Organ Size / Q000528:radiation effects; D015021:Yttrium Radioisotopes / Q000627:therapeutic use
D015021:Yttrium Radioisotopes