2021 CSCO Differentiated Thyroid Cancer Diagnosis and Treatment Guidelines Series Interpretation - Prof. Luo Yukun's Interpretation of Ablation Therapy

, Introduction Differential thyroid cancer (DTC) treatment methods include: surgery, endocrine therapy, radiotherapy and systemic therapy
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Ablation therapy has become an important supplementary treatment method for DTC diagnosis and treatment due to its simple operation, safety and effectiveness, and few complications
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In order to standardize the application of ablation therapy in the diagnosis and treatment of DTC, so that patients can obtain more quality survival benefits, Chinese multidisciplinary experts combined the latest evidence-based medical evidence and clinical experience at home and abroad, and jointly compiled the "Chinese Society of Clinical Oncology (CSCO)".
Guidelines for the diagnosis and treatment of differentiated thyroid cancer (2021)” (hereinafter referred to as the “Guidelines”)
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Yimaitong specially invited Professor Luo Yukun from the First Medical Center of the PLA General Hospital to interpret the ablation treatment chapter in the "Guide" for us
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Expert Profile Luo Yukun Director of the Ultrasound Diagnostic Department of the First Medical Center, chief physician, professor, doctoral tutor
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He is good at ultrasound diagnosis of abdomen, thyroid, breast, blood vessels, etc.
and ultrasound intervention (tumor ablation therapy, catheter placement, drug-targeted therapy, etc.
) , the curative effect is at the leading level
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He has won the Beijing Outstanding Physician Award, the National Famous Physician·Excellent Demeanor, the title of China's Outstanding Sonographer, and the "Bethune->
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He is currently the chairman of the Beijing Society of Ultrasound Medicine, the vice chairman of the Ultrasound Specialist Committee of the Chinese Medical Doctor Association, and the chairman of the Ultrasound Medicine Professional Committee of the China Research Hospital Association
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He has undertaken more than 20 national, provincial and ministerial-level projects, published more than 100 academic papers, won 1 first prize and 3 second prizes of the Army Science and Technology Progress Award, and 14 national patents.

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Ablation therapy is the use of physical or chemical methods to inactivate tumor cells in situ under the guidance of ultrasound, coagulation necrosis occurs in the lesion tissue, and finally the necrotic tissue is naturally dissolved and absorbed by the body, thereby eradicating or destroying the tumor in situ 1
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According to the different indications of DTC ablation treatment, the "Guide" gives different levels of treatment recommendations and guidance
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Table 1 Recommendations for ablation therapy in the Guidelines 1 Recommendation: For patients with primary low-risk papillary thyroid microcarcinoma, if the patient has the need to preserve glandular function and aesthetics, and refuses surgery or observation, ablation therapy can be considered Interpretation 1: Comprehensive consideration of the patient Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer, accounting for about 85% to 90% of all thyroid cancers1,2
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Among them, papillary thyroid microcarcinoma (PTMC) with a diameter of ≤10 mm accounts for about 50% to 60% of the PTC population
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PTMC has the characteristics of slow progression and good prognosis
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For low-risk PTMC, the American Thyroid Association (ATA) believes that follow-up observation can be considered after adequate communication with patients and their families
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However, during the long-term observation of survival with cancer, some patients have greater psychological pressure
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In this case, ultrasound-guided thermal ablation techniques can be used 3
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This technique can not only achieve good therapeutic effect, but also avoid excessive trauma caused by surgery, reduce the patient's anxiety, and preserve thyroid function 3
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A long-term follow-up study from South Korea showed that ultrasound-guided radiofrequency ablation has good efficacy in low-risk PTMC patients, and no local tumor progression, distant metastasis, or surgery-related death occurred during more than 5 years of follow-up.
4
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A long-term follow-up study from China showed that the survival curve of low-risk PTMC patients who received ultrasound-guided radiofrequency ablation was not significantly different from that of surgical patients, and had a higher quality of life 5
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It should be noted that PTMC thermal ablation treatment should be strictly controlled for indications, fully informed by the patient, and performed under the standard operation of qualified professionals 3
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Interpretation 2: Pay attention to preoperative evaluation and postoperative efficacy evaluation.
The thyroid is closely related to the common carotid artery, trachea, and recurrent laryngeal nerve and other important structures in the neck
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Therefore, whether it is a primary lesion or a recurrent and metastatic lesion, the patient's condition should be fully assessed before ablation therapy is used, which should include medical history inquiry, imaging examination, pathological puncture, etc.
Anatomy
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Liquid isolation is an important measure to improve the safety of ablation therapy
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During ablation, fixed ablation or mobile ablation should be used according to the size of the nodule; contrast-enhanced ultrasonography should be performed immediately after ablation, and the ablation treatment area showed no enhancement, more than 3 mm beyond the edge of the nodule, to ensure complete ablation of the lesion 1
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In addition, the efficacy of ablation therapy should be comprehensively evaluated in combination with evaluation indicators such as lesion volume, volume reduction rate, and lesion disappearance rate
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Recommendation: For patients with in situ recurrence and persistent/recurrent lateral cervical lymph node metastases, if the patient has high surgical risk or is refractory to radioactive iodine or refuses surgical treatment, ablation therapy may be considered.
One of the conventional treatments for metastatic DTC, but surgical scarring may increase the complications of reoperation
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In addition, in the process of clinical diagnosis and treatment, it is often faced with the risk of secondary surgery for elderly patients and the situation that patients refuse surgery
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Therefore, ablation therapy can be used as an alternative or palliative therapy for in situ recurrent thyroid cancer or for lateral neck lymph node metastases in patients with high surgical risk or who refuse surgery.

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Reference materials: 1.
Guidelines Working Committee of the Chinese Society of Clinical Oncology.
Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Differentiated Thyroid Cancer (2021) [M].
People's Health Publishing House 2.
Guidelines for the diagnosis and treatment of thyroid cancer (2018 edition) 3.
Thyroid cancer Expert consensus on the indications of thermal ablation for micropapillary carcinoma[J].
Chinese Journal of Medical Ultrasound(Electronic Edition),2019,16(08):571-574.
4, Cho SJ, Baek SM, Lim HK, Lee KD, Son JM, Baek JH.
Long-Term Follow-Up Results of Ultrasound-Guided Radiofrequency Ablation for Low-Risk Papillary Thyroid Microcarcinoma: More Than 5-Year Follow-Up for 84 Tumors.
Thyroid.
2020;30(12):1745-1751.
5, Zhang M, Tufano RP, Russell JO, et al.
Ultrasound-Guided Radiofrequency Ablation Versus Surgery for Low-Risk Papillary Thyroid Microcarcinoma: Results of Over 5 Years' Follow-Up.
Thyroid.
2020;30(3):408-417.