TONGUE CANCER
(Prepared by Dr Jaime Carmona)
Male, 74 year old, ex-smoker with a history of cancer of the tongue base (invasive squamous cell carcinoma). PET-FDG with 13 mCi, injected with blood glucose level of 124 mg/dl showed irregular area of intense tracer uptake measuring approximately 4.9 x 3.4 cm with maximum SUV uptake of 20.8 (black arrows). In addition, two focus are displayed with moderate activity at high left lateral cervical region measuring up to 1.3 cm and maximum SUV of 5.1 (red arrows). Likewise, another one of moderate concentration of labeled glucose in the posterior mediastinum in the midline, measuring 1.8 cm and maximum SUV of 5.2 (blue arrow).
Horiuchi C et al found that FDG-PET is especially useful to detect distant metastasis, double cancer with head and neck cancer and unknown primary tumor with metastatic neck lymph nodes. The conventional modalities, e. g., CT or MRI, show anatomical images in the body. FDG-PET can estimate metabolic activity in cancer and is useful in evaluating or monitoring the response to concurrent chemoradiotherapy of the head and neck cancer. However, we should recognize the limitations of FDG -PET. An acute inflammatory disease shows high FDG uptake like cancer.
Huang SH at described the sensitivity and specificity of fused PET/MRI were also
highest among the 4 modalities (90.0%/90.9%, 80.0%/84.1%, 80.0%/79.5%, and
55.0%/81.8%, respectively). The maximal lesion size was 3.0 to 6.0 cm in the
pathology specimen. Regression analysis showed better agreement between fused
PET/MRI and pathology results. Fused PET/MRI is more reliable for focal invasion
assessment and tumor size delineation in advanced BSCC compared with PET/CT,
MRI, and CT. PET/CT has the lowest confidence level, which may limit its use in
the clinical setting.
References:
1 Horiuchi C, Tsukuda M, Matsuda H, Taguchi T, Nishimura G, Takahashi M, Watanabe M, Komatsu M. . The role and limitations of FDG-PET in head and neck cancer. Gan To Kagaku Ryoho 2009 Dec; 36 (13): 2542-6.
2 Huang SH, Chien CY, Lin WC, Fang FM, Wang PW, Lui CC, Huang YC, Hung BT, Tu MC, Chang CC. A Comparative Study of Fused FDG PET/MRI, PET/CT, MRI, and CT Imaging for Assessing Surrounding Tissue Invasion of Advanced Buccal Squamous Cell Carcinoma. Clin Nucl Med. 2011 Jul;36(7):518-525.