Author |
원경숙(Kyoung Sook Won),류진숙(Jin Sook Ryu),문대혁(Dae Hyuk Moon),양승오(Seoung Oh Yang),이희경(Hee Kyung Lee),이정교(Jung Kyo Lee),권병덕(Byung Duk Kwun), |
Abstract |
Following radiation therapy for brain tumors, patients
often have clinical deterioration due to either
radiation necrosis or recurrent tumor progression in
the treatment field. The distinction between these
entities is important but difficult clinically or even
with CT or MRI. T1-201 has been known to accumulate in
various tumors and be useful to grade, predict
prognosis or detect recurrence of glioma. The aim of
this study was to evaluate the usefulness of T1-201
SPECT in the differentiation of recurrent tumor from
radiation necrosis. Of 67 patients who did T1-201 brain
SPECT imaging with clinically suspected recurrent tumor
or radiation necrosis, 20 patients underwent
histopathological examination and constituted the study
population. T1-201 uptake indices on T1-201 brain SPECT
imaging were calculated and correlated with
histopathological diagnosis. Of 20 patients, 15 were
histopathologically confirmed as recurrent original
tumor or malignant transformation of benign tumor and 5
were diagnosed as radiation necrosis. On T1-201 SPECT,
18 of 20 had T1-201 index above 2.5 which was regarded
as positive indicator for the presence of tumor.
Seventeen cases showed concordance, which consisted of
15 true positive and 2 true negative. Discordant 3
cases were all false positive. There was no case of
false negative. The sensitivity, specificity, positive
and negative predictive value of T1-201 SPECT were
100%, 40%, 83% and 100%. In conclusion, T1-201 brain
SPECT is a sensitive diagnostic test in the detection
of recurrent tumor following radiation therapy and is
useful in the differentiation of recurrent tumor from
radiation necrosis. Relatively low specificity should
be evaluated further in larger number of patients in
consideration of sampling error and referral bias for
pathologic examination. |