Intraoperative sentinel node biopsy in patients with squamous cell carcinomas of the head and neck--experiences using a well-type NaI detector for gamma ray spectroscopy.

: The sentinel node (SN) biopsy in an actually discussed topic. The use of a well-type NaI detector for gamma ray spectroscopy (WTD) beside the use of a handheld gamma probe (HGP), is investigated. In 18 patients suffering from a head and neck squamous cell carcinoma (HNSCC) with different lymph node status an intraoperative SN biopsy was accomplished with a HGP. 64 separately taken lymph nodes were supplied to an additional measurement in a WTD. A tumor-free SN represented the tumor-free lymph node status in 9 patients. In 5 cases an isolated tumor metastasis could be proven in the SN. SN biopsy has no meaningfullness in cases of advanced metastatic spread ipsilaterally, but possibly in contralateral N0-neck. In 64 separately investigated lymph nodes an activity enrichment could be proven in the WTD. With this procedure small count rates could be determined in contrast to the HGP. The distinction of weakly enriching lymph nodes was less favourable with the HGP but successful with the WTD. The additional use of a WTD offers a more exact distinction of intranodal disintegration rates of the draining lymph nodes. The WTD may increase the security of intraoperative SN biopsy.