Potential of (99m)Tc-MIBI for detecting bone marrow metastases.
In this study, we evaluated the potential of (99m)Tc-hexakis-2-methoxyisobutylisonitrile (MIBI) for detecting bone metastases in comparison with a conventional bone tracer.


METHODS
(99m)Tc-MIBI and (99m)Tc-hydroxymethylene diphosphonate (HMDP) scans were obtained from 99 patients with proven malignant diseases and suspected bone metastases. We compared 373 lesions that showed abnormal uptake on (99m)Tc-MIBI scans or (99m)Tc-HMDP scans (or both).


RESULTS
Bone metastases were confirmed in 334 of 373 lesions. Thirty-nine lesions on (99m)Tc-HMDP scans had false-positive findings, but only 2 of these lesions had false-positive findings on (99m)Tc-MIBI scans. (99m)Tc-MIBI and (99m)Tc-HMDP scans were equivalent in 168 of 334 lesions (50.3%). (99m)Tc-MIBI scans correctly detected more lesions than (99m)Tc-HMDP scans: 284 lesions (85.0%) versus 218 lesions (65.3%) (P < 0.005), respectively. (99m)Tc-MIBI scans showed a markedly higher sensitivity for detecting metastases in the femur and humerus compared with (99m)Tc-HMDP scans: 97 of 98 lesions (99.0%) versus 35 of 98 lesions (35.7%) (P < 0.005) and 21 of 22 lesions (95.5%) versus 11 of 22 lesions (50.0%) (P < 0.005), respectively. (99m)Tc-HMDP scans of 17 patients showed no abnormal images. However, (99m)Tc-MIBI scans correctly detected bone metastases, and subsequent development of multiple lesions was observed on follow-up (99m)Tc-HMDP scans of 15 patients. (99m)Tc-MIBI scans were superior to (99m)Tc-HMDP scans in the detection of metastases attributed to breast cancer, multiple myeloma, and hepatoma. On the contrary, (99m)Tc-MIBI scans were less sensitive than (99m)Tc-HMDP scans for detecting bone metastases attributed to prostate cancer in the other skeletal sites except for femur and humerus.


CONCLUSIONS
(99m)Tc-MIBI scans have better sensitivity for detecting bone metastases and provide more specific complementary findings than conventional bone scans. (99m)Tc-MIBI accumulation attributed to bone marrow metastases may occur at an early stage, before the bone remodeling process in the surrounding bone can be detected on conventional bone scans.
Wakasugi
Shigetoshi
S
Department of Nuclear Medicine, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Noguti
Atushi
A
Katuda
Toshizou
T
Hashizume
Terumi
T
Hasegawa
Yoshihisa
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019046:Bone Marrow Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D001859:Bone Neoplasms / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives*; D017256:Technetium Tc 99m Sestamibi
C024226:technetium Tc 99m hydroxymethylene diphosphonate; D017256:Technetium Tc 99m Sestamibi; D013669:Technetium Tc 99m Medronate