F-18-2-Fluoro-2-Deoxyglucose Positron Emission Tomography Compared to Technetium-99m Hexakis-2-Methoxyisobutyl Isonitrile Single Photon Emission Chest Tomography in the Diagnosis of Indeterminate Lung Lesions

Abstract

Background:¹⁸FDG-PET plays a significant role in diagnosing malignancy of lung lesions but remains an expensive test available at a limited number of sites in Italy. Objective: We prospectively compare the diagnostic accuracy of ^99mTc-MIBI- SPECT and ¹⁸FDG-PET in patients with indeterminate lung lesions to demonstrate that ^99mTc-MIBI-SPECT may be considered as a valid alternative when ¹⁸FDG-PET is not available. Methods: 52 patients with indeterminate lung lesion were examined by ¹⁸FDG-PET and ^99mTc-MIBI-SPECT before surgery. The scintigraphic findings were analyzed visually and semiquantitatively and then correlated to the definitive diagnosis. Results: 38 were malignant lesions while 14 were benign. At visual analysis, the sensitivities of ¹⁸FDG-PET and ^99mTc-MIBI-SPECT were 92 and 84%, respectively (McNemar test p = 0.4), whereas the specificities were 78.6 and of 93% (p = 1.0), respectively. At semiquantitative analysis, ¹⁸FDG-PET showed a sensitivity and specificity of 92 and 71.4%, respectively, while ^99mTc-MIBI-SPECT produced a sensitivity and specificity of 86 and 100%, respectively (p = 0.194). For lymph node staging, ¹⁸FDG-PET and ^99mTc-MIBI-SPECT have a sensitivity and specificity of 88 and 92 of 77 and 100%, respectively. Conclusion:^99mTc-MIBI-SPECT is similar to ¹⁸FDG-PET in the detection of lung malignancies and represents an alternative when PET is not available. Yet, the combination of both techniques may improve patient selection for surgery.

Diagnostic Performances of 99mTc-Methoxy Isobutyl Isonitrile Scan in Predicting the Malignancy of Lung Lesions

“…The literature search process is demonstrated as a flowchart in Figure 1 . Of the 15 articles deemed eligible for inclusion, 10 , 12 , 27 – 30 , 32 – 39 one pair of article by Nikoletic et al 31 , 32 had overlapping data; thus, only the latest article 32 was included. Consequently, the final review comprised 14 studies.…”

“…However, a direct comparison between PET and SPECT is in the absence. Only 2 of the studies 30 , 39 compared SPECT with PET included in our meta-analysis, but the results were generally inconclusive. According to Santini et al, 30 99m Tc-MIBI SPECT was similar to FDG-PET in the detection of lung malignancies and represents an alternative if PET was not available.…”

“…Only 2 of the studies 30 , 39 compared SPECT with PET included in our meta-analysis, but the results were generally inconclusive. According to Santini et al, 30 99m Tc-MIBI SPECT was similar to FDG-PET in the detection of lung malignancies and represents an alternative if PET was not available. Finally, a further interesting point of discussion is a comparison of PET and 99m Tc-MIBI SPECT to estimate the value of these modalities in differentiating malignant and benign lung lesion.…”

In the era of ultrasound technology, could conventional trans-bronchial needle aspiration still play a role in lung cancer mediastinal staging?

“…All patients received a contrast enhanced whole body PET/CT. Mediastinal LNs were considered potentially metastatic if the short-axis diameter was >10 mm and/or the standardized uptake value (SUV) was >2.5 or had an uptake greater than the background activity of the mediastinum (13,14). TBNA biopsy was subcategorized and analyzed for diagnostic success based on the LN station as paratracheal (stations 2R, 4R, 2L, 4L) and subcarinal (station 7) according to the Mountain-Dresler classification (15) and on LN size (measure in mm).…”

Recent developments in PET and SPECT imaging

“…This is particularly advantageous when labelling small molecules for targeting structurally sensitive targets such as the brain. However, these advantages have to be set against the high capital costs involved in setting up a PET facility, and this suggests that this technique will not be available in the less developed areas of the world in the near future . The advantages of PET are perhaps less clear cut for preclinical small animal imaging where the higher sensitivity of PET (around 15 times higher based on phantom imaging) is offset by the higher resolution attainable using SPECT.…”