Comparison of 18F FDG-PET and CT/MRI for the Diagnosis of Cervical Lymph Node Metastasis in Head and Neck Cancer: A Level-by-Level Based Study / 대한핵의학회잡지

PURPOSE: Cervical lymph node metastasis is the most important factor of the prognosis and therapeutic planning in head and neck cancer. With increasing interest of minimally invasive neck surgery, more accurate preoperative assessment of cervical lymph node becomes more essential. We evaluated the diagnostic accuracy of 18F FDG-PET in the assessment of lymph node metastasis in patients with primary head and neck cancer and compared the results with those of CT/MRI. MATERIALS AND METHODS: Thirty-two patients (M/F=27/5, 56 +/- 10yr) with biopsy proven head and neck cancer (16 supraglottic cancer, 9 tongue cancer, 7 others) underwent FDG-PET and CT/MRI (25/7) within 1 month before neck dissection. Based on lymph node level, the diagnostic sensitivity and specificity of FDG PET and CT/MRI for the metastasis of cervical lymph node were compared. RESULTS: Of 153 lymph node levels dissected in 32 patients, 32 lymph node levels of 19 patients were positive for metastasis by histopatholologic examination. The overall sensitivity and specificity of FDG-PET were 88% (28/32) and 93% (113/121), whereas those of CT/MRI were 56% (18/32) (p=0.002) and 92% (112/121), respectively. The diagnostic sensitivity and specificity of FDG-PET were different according to location of lymph node levels, and those of ipsilateral level II were lower than those of other levels. CONCLUSION: FDG-PET is more sensitive in detecting metastatic cervical lymph node in head and neck cancer than CT/MRI. FDG-PET might be useful in guiding the extent of neck dissection.

The Reconstruction of the Recurrent Laryngeal Nerve after the Combined Resection of the Recurrent Laryngeal Nerve and the Papillary Thyroid Cancer

BACKGROUND: The function of the recurrent laryngeal nerve might be normal even though there is some extent of cancer invasion. The recurrent laryngeal nerves are usually saved when the preoperative vocal function is normal. However, it is difficult to save a nerve with a minimal amount of remnant cancer tissue when the cancer invasion is deep and broad. In a such instance, combined resection of the recurrent nerve and reconstruction of the recurrent nerve could be considered if the postoperative recovery of the vocal function is acceptable. METHODS: We tried reconstruction of the recurrent laryngeal nerve with the ansa hypoglossi-recurrent nerve (n=6) and with direct end-to-end anastomosis (n=4). The postoperative vocal function of these patients were compared to that of 11 patients whose recurrent nerves were resected and left without reconstruction. RESULTS: The maximal comfortable phonation time of the reconstruction group was significantly longer (mean 11.4+/-3.8 sec) than that of the no reconstruction group (mean 6.9+/-3.2 sec). There was, however, no significant difference between the ansa hypoglossi-recurrent nerve anastomosis group (mean 11.5+/-4.5 sec) and the direct end-to-end anastomosis group (mean 11.3+/-3.0 sec). Median fixation of the vocal cord and no or minimal glottic gap were observed in the reconstructed group. On the other hand, in the no reconstruction group paramedian fixation of the vocal cord and a wider glottic gap were observed. CONCLUSIONS: We feel that the recovery of the vocal function after the reconstruction of the recurrent nerve is acceptable and is enough to try a combined resection of a recurrent nerve severely invaded by papillary thyroid cancer even though the pre operative vocal function is normal.