Technetium (99mTc) Phytate

This study aimed to evaluate usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC).

Sixteen patients with MTC were enrolled in the study from January 2013 to June 2019. Intratumoral injection of technetium (Tc)‐99m phytate followed by lymphoscintigraphy was performed preoperatively. Lateral sentinel lymph nodes were detected by a collimated gamma probe and underwent frozen analysis. Ipsilateral LND was performed in all patients to assess lateral LN status.

The identification rate of sentinel lymph nodes (SLNs) detected by radioisotope was 87.5% (14 of 16 patients). The sensitivity, specificity, positive predictive value, and negative predictive value of frozen analyses were 66.7%, 100%, 100%, and 91.6%, respectively. Based on final histopathology, however, the diagnostic values of lateral SLNB were all 100%.

This study showed that lateral SLNB can be a promising surgical tool for decisions on LND in patients with MTC.

A major controversy in sentinel node (SN) biopsy of endometrial cancer is the injection site of mapping material. We compared lymphatic drainage pathways of the uterine cervix and uterine body in the same patients by head-to-head comparison of intracervical radiotracer and fundal blue dye injections.

All patients with pathologically proven endometrial cancer were included. Each patient received 2 intracervical injections of 99mTc-phytate. At the time of laparotomy, the uterus was exposed, and each patient was injected with 2 aliquots of patent blue V (2 mL each) in the subserosal fundal midline locations. The anatomical locations of all hot, blue, or hot/blue SNs were recorded.

Overall, 45 patients entered the study. At least 1 SN could be identified in 75 of 90 hemipelves (83.3% overall detection rate, 82.2% for radiotracer [intracervical] alone, and 81.1% for blue dye [fundal] alone). In 71 hemipelves, SNs were identified with both blue dye (fundal) and radiotracer (intracervical) injections. In 69 of these 71 hemipelves, at least 1 blue/hot SN could be identified (97.18% concordance rate). In 10 patients, para-aortic SNs were identified. All of these nodes were identified by fundal blue dye injection, and only 2 were hot.

Our study shows that lymphatic drainage to the pelvic area from the uterine corpus matches the lymphatic pathways from the cervix, and both intracervical and fundal injections of SN mapping materials go to the same pelvic SNs.