Lack of correlation of functional scintigraphy with (99m)technetium-methoxyisobutylisonitrile with histological necrosis following induction chemotherapy or measures of P-glycoprotein expression in high-grade osteosarcoma.
In osteosarcoma, some studies have suggested P-glycoprotein expression is a prognostic factor. The clearance of (99m)technetium hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been used in some tumor systems as an in vivo measure of P-glycoprotein-mediated efflux. In this study we explored the correlation between (99m)Tc-MIBI clearance and histological necrosis following induction chemotherapy and P-glycoprotein expression in osteosarcoma. The primary tumors of 20 patients with high-grade osteosarcoma were imaged at diagnosis with (99m)Tc-MIBI, and the uptake ratios and biological half-lives were calculated. P-Glycoprotein expression in the tumor tissue was determined immunohistochemically and by measuring mRNA expression of the multidrug resistance-1 gene. The histological necrosis following induction chemotherapy was assessed by the Huvos grading system. The biological half-life of (99m)Tc-MIBI ranged from 1.4 to 52.5 h. Seven of the 20 tumor samples had a favorable extent of necrosis following induction chemotherapy. The (99m)Tc-MIBI half-life and uptake ratio showed no correlation with histological necrosis following induction chemotherapy. The (99m)Tc-MIBI half-life and uptake ratio did not correlate with either measure of P-glycoprotein expression. The results of this pilot study indicate that (99m)Tc-MIBI imaging is not an effective predictor of histological necrosis following induction chemotherapy in high-grade osteosarcoma. (99m)Tc-MIBI imaging did not correlate with measures of P-glycoprotein expression in the tumor tissue.
Gorlick
R
R
Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA. gorlickr@mskcc.org
Liao
A C
AC
Antonescu
C
C
Huvos
A G
AG
Healey
J H
JH
Sowers
R
R
Daras
M
M
Calleja
E
E
Wexler
L H
LH
Panicek
D
D
Meyers
P A
PA
Yeh
S D
SD
Larson
S M
SM
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D002648:Child; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009336:Necrosis; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics; D010865:Pilot Projects; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D011877:Radionuclide Imaging; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012334:RNA, Neoplasm; D017256:Technetium Tc 99m Sestamibi