What is interventional radiology for thyroid conditions?

The incidence of thyroid disease among children and adolescents has increased in the past decade. Physicians at the Pediatric Thyroid Center at Children’s Hospital of Philadelphia (CHOP) are actively investigating and trialing minimally invasive diagnostic and therapeutic procedures. Their goal is to reduce the need for open surgery by using imaging tools to guide new, minimally invasive techniques.

While the Interventional Radiology (IR) Department at CHOP offers a full range of minimally invasive procedures, a few specific practices have proven successful in treating pediatric thyroid conditions. At CHOP, a dedicated team of thyroid experts, radiologists, registered nurses, physician assistants, nurse practitioners, clinical coordinators, sedation physicians and others work together to provide these procedures and treatments to pediatric patients in CHOP’s state-of-the-art interventional radiology suites.

Using IR to treat thyroid conditions

Traditional treatment for thyroid conditions included surgery, but this sometimes carries increased risk, and recovery was often prolonged. Today, many thyroid conditions – like thyroid nodules – can be safely diagnosed and treated by the interventional radiologist with minimally invasive, targeted procedures that shrink or “cook” the lesions, rendering them no longer functional. The most common interventional radiology procedures for thyroid conditions include the following:

Fine-needle aspiration biopsy

Fine-needle aspiration biopsy (FNAB) is considered the gold-standard for the diagnosis of thyroid nodules due to its safety, reliability, low cost and high patient tolerance. FNAB is performed using ultrasound guidance, allowing real-time control of the needle tip to avoid impacting vascular structures.

Percutaneous ethanol injection

Percutaneous ethanol injection (PEI) is a minimally invasive technique that introduces ethanol into targeted tissues, causing an inflammatory reaction that constricts blood flow and causes the nodule to shrink. In some cases, repeated PEI is required. PEI is commonly used for treatment of benign solid nodules and cysts when alternatives are less desirable, or to destroy papillary lymph nodes that have become cancerous.

Laser thermal ablation

Laser thermal ablation (LTA), sometimes called fiberoptic thermal ablation, is a minimally invasive technique that can treat cancerous lymph nodes and reduce the size of symptomatic thyroid nodules. This treatment can reduce large benign nodules without affecting thyroid function. By using targeted lasers to heat up the thyroid nodule, it causes necrosis (tissue death), followed by fibrosis (scar tissue) and a reduction in the size of the nodule.

Radiofrequency ablation

Radiofrequency ablation (RFA) is a newer minimally invasive technique often used to treat bone and abdominal tumors. Similar to laser thermal ablation, RFA can be used to treat benign thyroid nodules causing symptoms or cosmetic problems, or recurrent cancerous foci.

Treatment at CHOP Interventional Radiology

The decision about whether interventional radiology should be performed on a patient and which specific procedure should be undertaken is made jointly by the Thyroid and Interventional Radiology teams, in consultation with the patient and family. In most cases, interventional radiology procedures for thyroid conditions are performed on an outpatient basis and patients are released the same day.

The following is general information about scheduling, arrival to the IR suite and how to prepare your child. For answers to specific questions about your child’s procedure at CHOP, please call the Interventional Radiology Nurse scheduler at 215-590-7000.

IR scheduling and arrival

If your physician has told you that your child needs to have an Interventional Radiology procedure, please call the IR nurse scheduler at 215-590-7000 (press #1 at the first prompt, press #2 at the second prompt).

The nurse scheduler will ask questions about your child's medical history, including medications and whether your child has had reactions to sedation or anesthesia in the past.

Your doctor or an IR nurse will give you special instructions, if any. In most cases, your child will not be able to eat or drink before the procedure, particularly if your child will be sedated or undergo anesthesia.

About two weeks before your child's appointment, we will send you instructions about the specific procedure your child will have completed. Please keep these instructions in a safe place where you can refer to them before your appointment.

Please let the IR team know if your child has any special needs. Our goal is to make this experience as stress free as possible for you and your child.

What should you do when you arrive?

Please arrive 45 minutes before your appointment. Check in to Outpatient Registration, on the third floor of the Main Hospital on CHOP’s Philadelphia campus. It is important that you arrive on time. Otherwise, the procedure may be canceled.

Your referring physician must fax us a copy of a procedure request form stating the type of procedure and reason for it. An interventional exam is not scheduled without this form or prescription. We’ll also need proof of insurance and a referral, if required by your insurer.

When the registration process is complete, we will notify Interventional Radiology. A technologist, nurse or technician will come out to the central registration area and bring you and your child to a room for IV placement or other preparations.

Preparing your child

CHOP’s child life specialists can help you prepare your child and support them during the procedure. We can also arrange to have a child life specialist at your child's appointment to explain the procedure in developmentally appropriate ways and to help your child better cope with the stress of the hospital experience.

Follow-up and outcomes

The follow-up for patients after image-guided interventions depends largely on the condition being treated. For example, benign symptomatic thyroid nodules may be treated with ethanol ablation alone, thermal ablation or a combination of the two, depending on the composition of the thyroid nodule. In most cases, for purely or predominantly cystic lesions, ethanol ablation is preferred over thermal ablation. The success rate of using ethanol ablation for pure thyroid cysts is 85-98%.

The overall therapeutic success rate for predominantly solid benign thyroid nodules – as defined as a 50% reduction in nodule size – was 97.8% in a 2018 multi-institution study.¹

At CHOP, predominantly cystic thyroid nodules, that are benign, are typically treated with ethanol ablation and a follow-up ultrasound is performed 6 months post-procedure. If the outcome is successful, the patient typically will only need clinical follow-up.

For predominately solid benign nodules, surveillance is longer and often includes follow-up for potential complications within the first month or two, then additional visits between 6 and 12 months to measure any objective changes in the treated nodules with ultrasound. Technical success is defined as a volume reduction of 50%; clinical success can be assessed by improvements in compressive symptoms and cosmetic bulge.

Recurrent thyroid cancer metastasis can be treated with ethanol or thermal ablation. Currently, CHOP is only using ethanol ablation, but plans are underway to offer laser thermal ablation for this indication soon. For those with recurrent thyroid cancer, fewer than one in four patients will require surgical resection after ablation.

Patients with recurrent thyroid cancer that has been treated with interventional radiology techniques will require periodic measurement of serum thyroglobulin levels and ultrasound monitoring to monitor response to ablation therapy. The reason for surveillance is to detect persistent or recurrent disease. The first visit is 3 to 6 months after treatment. Longer-term follow-up may be every 6 months or yearly depending on evidence of tumor activity.

Reference

1. Jung SL, Baek JH, Lee JH, et al. Efficacy and Safety of Radiofrequency Ablation for Benign Thyroid Nodules: A Prospective Multicenter Study. Korean J Radiol. 2018;19(1):167-174.