Imaging of nasopharyngeal carcinoma with Tc-99m MIBI.
OBJECTIVE
Differentiation of recurrent nasopharyngeal carcinoma (NPC) from radiation fibrosis using conventional diagnostic methods can be difficult. The authors prospectively studied patients with NPC to determine the efficacy of Tc-99m MIBI scintigraphy in detecting the primary, residual, and recurrent tumors.


METHODS
The authors performed Tc-99m MIBI SPECT studies of the head and neck and whole-body scans on 21 healthy adult volunteers and 43 patients with NPC before (n = 26) or after (n = 17) radiotherapy. The images were qualitatively assessed by comparing the nasopharyngeal uptake to scalp radioactivity. MIBI uptake index was calculated as a ratio of mean counts per pixel in the normal nasopharynx or tumor to mean counts per pixel in the scalp.


RESULTS
There was significantly higher uptake of Tc-99m MIBI by NPC than normal nasopharynx and radiation fibrosis (P < .05). The authors determined the optimum cutoff MIBI uptake index value of 1.3 with a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 96%, and an accuracy of 98% for diagnosing NPC.


CONCLUSIONS
This study suggests that Tc-99m MIBI SPECT is useful for detecting primary NPC and for differentiating residual or recurrent tumor from radiation fibrosis. The authors propose the cutoff MIBI uptake index value of 1.3 for diagnosing NPC.
Pui
M H
MH
Department of Nuclear Medicine, First Affiliated Hospital of Sun Yat-Sen University of Medical Sciences, Guangzhou, Peoples' Republic of China.
Du
J Q
JQ
Yueh
T C
TC
Zeng
S Q
SQ
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D003937:Diagnosis, Differential; D005260:Female; D005355:Fibrosis; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D009305:Nasopharynx / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects; D009333:Neck / Q000000981:diagnostic imaging; D009361:Neoplasm Invasiveness / Q000000981:diagnostic imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011832:Radiation Injuries / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D012535:Scalp / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi