Percutaneous Ethanol Injection for Thyroid Cancer Neck Nodal Recurrences and Thyroid and Parathyroid Cysts

Abstract

The use of ethanol for ablation of persistent nodal neck metastasis from thyroid cancer is a proven therapy alternative to another neck dissection, and it is a proven alternative to surgery for parathyroid and complex thyroid cysts with >50% fluid. If ultrasound evaluation is suspicious for a cancer node or complex cyst, then a fine needle aspiration (FNA) for lymph node cytology and needle washout studies for thyroglobulin and calcitonin must be positive, and the solid component of the cyst must be benign and molecular markers such as BRAF etc. are negative for thyroid cancer before considering ethanol therapy. Alternative methods to treat benign thyroid and parathyroid cysts with ethanol ablation percutaneous ethanol injection (PEI) prevent the expense and morbidity of a surgical procedure. Furthermore, the value of ethanol for ablation of nodal neck metastasis from thyroid cancer after prior neck dissection has been shown to save another surgery, and at the Mayo clinic, PEI saved 6 million dollars in 100 patients when nodes were ablated by ethanol. PEI Procedure for Thyroid and Parathyroid Cysts 1. Large cysts with local symptoms or cosmetic questions that have been biopsied and proven to be benign are candidates for PEI. Nodules with >50% cyst fluid can be treated by PEI. Because of cystic changes in papillary carcinoma, we recommend careful biopsy of the blood flow solid areas and collection of molecular markers before determining the nodule is ready for PEI. 2. Determine the volume of the cyst. 3. Draw up 50% of the cyst volume with 95%–99% ethanol. 4. Use a three-way stopcock with a large syringe to collect the fluid and another with the ethanol for injection. 5. Under US guidance, withdraw the cyst fluid until there is a small amount left around the needle tip. Switch the stopcock and have the assistant begin to slowly inject the ethanol. The sonologist must keep continuous view of the needle tip. 6. When the ethanol is injected, the sonologist withdraws the needle. Slight tingling along the needle track is transient. 7. Return visit in 4 weeks for ultrasound to see the progress in the regression of the cyst volume and determine if another PEI will be needed. 8. The same procedure is used for pure parathyroid cysts. Because they are never cancer, you only need the proof that they are of parathyroid origin by needle washout for parathyroid hormone. PEI for Thyroid Cancer Nodal Neck Metastasis 1. Candidates must have had a prior thyroidectomy and had at least one modified radical neck dissection on the side of the recurrence. Diagnostic detailed seven compartment endocrine neck ultrasound lymph node mapping followed by USG FNA with thyroglobulin or calcitonin needle washout of suspicious neck lymph nodes. 2. The ethanol is placed in a 1-cc syringe. 3. The sonologist guides the needle into the lymph node and injected 0.025 mL and asks the patient if they felt pain. If they did, the procedure is aborted. The lymph node capsule may be broached by the cancer. The other reason was bad positioned of the needle in the lymph node. After a 5-minute wait, a second try is possible. More pain is a definite cause for termination. If there is no pain, begin to inject 0.05 mL from the posterior of the node and finish at the anterior capsule. Again, a mild tingling sensation will occur at the withdrawal. Post-PEI loss of Doppler blood flow is a sign that the ethanol has ablated the node. 4. Patient returns for ultrasound size determination of the treated node. Additional PEI injections may be needed for some incompletely ablated nodes. 5. Any suspicious “lymph node” in the central compartment needs an additional needle washout for parathyroid hormone to prevent ablating a parathyroid gland. 6. Using a lidocaine injection around a cancer node can determine if the recurrent nerve is near. Transient hoarseness will tell you not to do the PEI. 7. A node that is not a candidate for PEI can be marked the day of the surgery with blue dye to help the surgeon find it. No competing financial interests exist. Runtime of video: 4 mins