The Value of 99mTc-MIBI SPECT/CT Imaging in Evaluation of Head and Neck Cancer in Children

Abstract

Introduction: Cancers that are known collectively as head and neck cancers can vary in their histological form and localization. This disease has a high social significance thus it require well-timed and delicate approach, especially in children. We can improve the accuracy of our methods by using new algorithms and technologies. We were the first to implement 99mTc-MIBI SPECT/CT imaging in evaluation of children with head and neck cancer and introduce it as a routine method in Russia. Purpose: Improve the accuracy in diagnostics of children with head and neck cancer by practical application of hybrid SPECT/CT method. To determine diagnostic value of planar scintigraphy and 99mTc-MIBI SPECT/CT in children with head and neck cancer. Material and methods: This study was performed as a prospective clinical study. Between January 2017 and December 2017, 53 patients which met the inclusion criteria were examined. The inclusion criteria were patients with histologically proven malignancy, age 1–18, weight more than 10 kg, up to date CT or MRI scans (less than two weeks passed from scanning), for initial patients a tumor findings (more than 20 mm in the largest scale). We concluded 61 whole body planar scintigraphy followed by head and neck 99mTc-MIBI SPECT/CT examinations. 10 patients were examined twice, 1patient was undergoing for this procedure for three times. Initial patients – 23, dynamic – 30. We performed scanning using a hybrid SPECT/CT after 15 minutes 99mTc-MIBI was injected. First stage was standard whole-body planar scintigraphy, second stage SPECT/CT (head and neck). Results: We evaluated diagnostic accuracy of planar scintigraphy and 99mTc-MIBI SPECT/CT. Planar scintigraphy sensitivity, specificity, NPV and PPV were 68.8, 96.6, 73.7, 95.7 %. SPECT/CT – 87.5, 96.6, 87.5, 96.6 %. The verification method was histological examination or follow-up imagining (CT or MRI) during a 12 month period. Additional imagining using hybrid SPECT/CT method allows us to increase sensitivity and NPV of isotope scanning. Most of false-negative results were obtained after planar scintigraphy, it can be related with image interpretation difficulties caused by equivocal image, especially, in patients during therapy. Six of such patients were correctly diagnosed with SPECT/CT and we revealed the presence of active tumor tissue. With CT we additionally detected destruction of skull bones in 10 patients. Conclusion: 1. Diagnostic accuracy of scintigraphy with 99mTc-MIBI is high: Sens. – 68.8 %. 2. We can increase diagnostic accuracy using hybrid methods, and so it plays an important role in final diagnosis: Sens. – 87.5 %, Spec. – 96.6 %. 3. SPECT/CT additionally detected destruction of skull bones even with negative scintigraphy results. 4. A strict clinical reasoning is needed in each individual case. 5. A further evaluation of the diagnostic capabilities of 99mTc-MIBI SPECT/CT in a larger number of patients appears justified.