Delineation of target volume for radiotherapy of high-grade gliomas by 99m Tc-MIBI SPECT and MRI fusion.
OBJECTIVE
Computed tomography (CT) and magnetic resonance imaging (MRI) are traditionally used for treatment planning of high-grade glioma. 99m Tc-methoxy-isobutyl-isonitrile (MIBI) single-photon emission computed tomography (SPECT) showed high sensitivity and specificity in literature series. In the present study, it was investigated how the information provided by 99m Tc-MIBI SPECT and MRI fusion could affect target delineation for radiotherapy of high-grade glioma.


METHODS
21 patients with high-grade glioma were studied by MRI and 99m Tc-MIBI SPECT imaging. The gross tumor volume (GTV) was outlined on MRI (MRI-GTV) and SPECT images (SPECT-GTV). Three additional volumes were analyzed: the (MRI+SPECT)-GTV representing the whole amount of MRI-GTV plus SPECT-GTV, the (MRI&SPECT)-GTV identified by the overlapping region of MRI-GTV and SPECT-GTV, and the (SPECT/MRI)-GTV identified by the extension of SPECT-GTV outside MRI-GTV.


RESULTS
MRI contrast-enhanced and 99m Tc-MIBI SPECT-positive lesions were found in all 21 patients. The average SPECT-GTV was slightly larger than the average MRI-GTV, with greater difference for resected than for unresected cases. The average increment of (MRI+SPECT)-GTV compared to MRI-GTV was 33%, being significantly higher for resected than for unresected cases (p = 0.006).


CONCLUSIONS
The fusion of 99m Tc-MIBI SPECT and MRI significantly affected the delineation of the target volume identified by MRI alone.
Radiotherapy, University of Piemonte Orientale, Novara, Italy. krengli@med.unipmn.it
Marco
M
Krengli
Gianfranco
G
Loi
Gianmauro
G
Sacchetti
Irene
I
Manfredda
Giuseppina
G
Gambaro
Marco
M
Brambilla
Alessandro
A
Carriero
Eugenio
E
Inglese
D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000532:radiotherapy* / Q000601:surgery; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005909:Glioblastoma / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000532:radiotherapy* / Q000601:surgery; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal / Q000379:methods*; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D017256:Technetium Tc 99m Sestamibi