Sentinel-Node-Markierung bei Plattenepithelkarzinomen des Kopfes und Halses

BACKGROUND

Commonly used staging procedures often cannot predict the absence of lymphatic micro- metastases in squamous cell carcinoma (SCC) of the head and neck. Therefore in many cases an elective neck dissection (ND) is necessary. In the surgical therapy of melanoma or breast cancer the presence of metastases can be evaluated securely by identification and examination of the sentinel lymph node (SLN). The type of surgical procedure is usually chosen in regard to the histopathological result. The present study evaluates the applicability of this concept for SCC of the head and neck.

METHODS

Radioactive labeled micro-albumin particles were injected preoperatively around the tumor in 38 patients without proven metastases. Following the excision of the primary tumor the sentinel lymph node/s were detected and dissected and ND was completed. Histological examination of the tissue was performed to evaluate whether the SLN reflected the lymphatic status.

RESULTS

In two cases (5.1 %) no SLN were detected. ND was completed in 32 cases. In nine cases (28.1 %) the SLN were infiltrated by the primary tumor. In 22 cases (68.8 %) SLN and ND revealed a N(0) stage. In one case (3.1 %) we could not identify a metastasis because of the anatomical closeness of the SLN to the primary. The negative predictive value was 96 %.

CONCLUSION

Predictive value regarding metastases to the neck was higher with the detection of SLN than with conventional staging procedures. Whether the detection of a tumor-free SLN is an indication not to perform an elective neck dissection is a matter of discussion, especially under the aspect of the effective reduction of postoperative morbidity.

[Comparison of the effectiveness of two different dosages of levothyroxine-iodide combinations for the therapy of euthyroid diffuse goiter]

BACKGROUND AND OBJECTIVE

Administration of levothyroxine and/or iodide can effectively reduce the volume of endemic goitre. However, TSH suppression during levothyroxine treatment may increase the number of recurrences through the persistence of intrathyroidal iodine deficiency. With special attention paid to the level of levothyroxine, a comparison was made of two dosages of combined levothyroxine and iodide.

PATIENTS AND METHODS

44 patients with diffuse euthyroid goitre were randomized to two treatment groups. Group A received 100 micrograms levothyroxine + 100 micrograms iodide, group B 75 micrograms levothyroxine + 150 micrograms iodide, all of them for three months. This was followed by three months without the medication. Intrathyroidal iodine concentration was measured at the onset of the study, then three months and six months later. At these same times thyroid volume was measured by ultrasound, as well as urinary iodine and various parameters of thyroid function.

RESULTS

Thyroid gland volume was reduced in both groups (group A: -17.3%; group B: -14.8%; p < 0.001). There was no significant difference of intrathyroidal iodine concentration and thyroid volume between both groups. After the treatment period, TSH suppression was more marked in group A, while TSH rise was greater in group B.

CONCLUSIONS

Both drug combinations resulted in comparable reduction of thyroid volume, while the intrathyroid concentration of iodine remained unchanged. The smaller rise of TSH after the treatment suggests that the dosage of 75 micrograms levothyroxine + 150 micrograms iodine is to be preferred.

X-ray fluorescence analysis (XFA) of thyroidal iodine content (TIC) with an improved measuring system

X-ray fluorescence analysis is based on the principal that the electron structure of stable iodine in the thyroid is excited by Americium-241 gamma rays to emit a characteristic fluorescence radiation which is proportional to the amount of iodine present in the gland. A stationary measuring system consisting of a 11.1 GBq Am-241 source and a high-purity Germanium detector with spectrum analyser has been improved by a PC guided method for sonographic definition of the measuring volume. The lower limit of detectibility of the system corresponds to 0.01 mg of Iodine per ml of thyroid volume; the in vivo precision given as coefficient of variation amounts to 15%. The thyroid is exposed with a radiation dose of 6 microSv per measurement. First studies with this improved system carried out in 50 female volunteers between 20 and 40 years of age with normal thyroid volumes resulted in a mean iodine concentration of the thyroid of 0.665 +/- 0.304 mg/ml. The mean iodine excretion in urine was normal with 10.8 +/- 10.4 microg/dl.