Bone SPECT to assess mandibular invasion by intraoral squamous-cell carcinomas.
It is important for head and neck surgeons planning their operative approach to assess tumor infiltration to the mandible by intraoral squamous-cell carcinomas. Two- to 3-hr planar bone scintigraphy is sensitive but not specific in detecting mandibular invasion by tumor. We evaluated 3-hr SPECT bone scintigraphy, which provides better anatomical detail, to determine if it more accurately assesses tumor invasion.


METHODS
Thirty consecutive patients with proven intraoral squamous-cell carcinomas were studied. Semiquantitative assessment of the mandible was performed with a three-level graded scoring system, based on comparisons of tracer uptake in the mandible to that in the upper cervical vertebrae and in an unaffected part of mandible. Lesion-to-cervical spine (L/S) count ratios and lesion-to-nonlesion (L/N) count ratios in the mandible on the 3-hr SPECT images were calculated.


RESULTS
All patients with proven tumor invasion showed higher tracer uptake than those with normal mandible or other dental diseases. The L/S and L/N count ratios on the SPECT images were significantly higher in patients with tumor invasion than in those without (L/S, p < 0.001; L/N, p < 0.01). L/S ratios provided better differentiation than L/N ratios.


CONCLUSIONS
Bone SPECT provides a reliable means of assessing tumor invasion to the mandible by intraoral squamous-cell carcinomas.
Department of Nuclear Medicine, Western General Hospital National Health Service Trust, Edinburgh, Scotland.
K W
KW
Chan
M V
MV
Merrick
R
R
Mitchell
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D008339:Mandibular Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D009060:Mouth Floor; D009062:Mouth Neoplasms / Q000473:pathology*; D009361:Neoplasm Invasiveness; D013669:Technetium Tc 99m Medronate; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
D013669:Technetium Tc 99m Medronate