[Palpation and sonography in after-care of head-neck tumor patients: comparison of ultrasound tumor entity parameters].

The ranking of postoperative palpation and sonography is examined in respect of imaging of neck lymph node enlargement and neck lymph node metastases or lymphomas, using a prospective study involving 127 patients whose head and neck tumours had already undergone treatment. These patients had been subjected to tumour aftercare for an average period of 26 months. Sonography is well suited for detecting the presence of enlarged neck lymph nodes, the accuracy being 97.5%. In this study palpation was clearly less safely defined, the accuracy being only 85%. The following results were obtained in respect of the specific imaging of metastases: sensitivity of palpation (75%) is below that of sonography (M/Q ratio) (93%). In respect of specificity palpation also yielded poorer results than sonography (M/Q ratio 94%) because of the relatively high proportion of false positive palpations (17%). The reason for this is non-differentiation between reactively enlarged lymph nodes and lymph nodes metastases. The advantage of sonography vs palpation by using the M/Q ratio is therefore the accuracy of the findings (94% sonography, 81% palpation) and hence the clear reduction in false positive and false negative findings. Furthermore, sonography can image the exact relationship to surrounding tissue and especially the vessels. The drawback of sonography is that lymph nodes < 9 mm maximal diameter cannot be assessed with the safety and accuracy mentioned above. Sonomorphological criteria such as the central marrow reflex and a widened lymphatic node cortex enhance diagnostic safety of the sonographic expansion parameters to yield an assessment of tumour status.