Technical Description
Appropriate patients are selected on the basis of having cytologically
proven recurrent DTC that cannot be managed with ablative radioiodine
and have small volume non-palpable recurrent disease in the neck at the
site of previous surgery (either thyroid bed or neck dissection). The
patient is subject to general anaesthesia, and prior to the skin
incision the lesions are re-identified and confirmed using US. Between
0.5 - 2.0 ml of sterile activated charcoal suspension (Charcotrace®) is
injected by an experienced Head and Neck radiologist under ultrasound
guidance either into the lesion or the tissues immediately superficial
to the target lesion. In addition, the lesion’s relationship to
anatomical landmarks and depth from the skin are imaged and reported to
the operating surgeon.
Where possible the previous thyroidectomy/neck dissection incision is
re-utilised and dissection is performed carefully towards the lesion
which is now easily identified visually due to the obvious charcoal
staining of the tissues immediately anterior to it, and the surgeon’s
knowledge of the site of the lesion relative to other anatomy. Once the
lesion is excised, a repeat US can be performed intra-operatively to
confirm excision before closure in equivocal cases. Recurrent laryngeal
nerve monitoring is used if the lesion is in proximity to the nerve.
Fig.1 The recurrent lesion is easily identified due to the
black hue of the charcoal dye anterior to its surface. Intra-operatively
the lesion was impalpable but was confirmed by the presence of
Charcotrace and pre/post resection ultrasound images, see figure 2.
Fig.2 Pre-operative (left hand image) ultrasound scan (USS)
demonstrates an irregular hypoechoic lesion medial to the carotid artery
and lateral to the tracheal wall (yellow arrow) consistent with
recurrent papillary thyroid cancer. The post-operative (left hand image)
USS demonstrates the lesion has completely resected. CA: Carotid Artery,
IJV: Internal Jugular Vein, TL: Tracheal Lumen