Early Dynamic Risk Stratification Decreases Rate of Ablative and Adjuvant Radioiodine Use in ATA Low and Intermediate Risk Papillary Thyroid Cancer Patients

Objectives: In differentiated thyroid cancer (DTC), radioiodine (RAI) therapy is most frequently employed for remnant ablation or as adjuvant therapy for the remaining disease. The application of RAI to patients classified as intermediate risk (InR) is still a matter of debate. The aim of this study is to analyze the effect of early postoperative risk assessment on RAI use on papillary thyroid cancer patients who are classified as low risk (LoR) or InR.
Methods: This is a single-center, prospective registry study. One-hundred-eighty-six patients operated between January 2012 and August 2021 and categorized as LoR or InR were included in this study. All patients had total thyroidectomy and central lymph node dissection by the same endocrine surgeon. An early dynamic risk assessment (EDRA) consisting of neck ultrasonography, serum thyroglobulin (Tg) and anti-Tg levels was performed 6 weeks after surgery. Most of the patients were either followed up without RAI or received ablative low activity (30–50 mCi) RAI based on predetermined criteria.
Results: Median follow-up was 63 months. Sixty-six (61%) patients in the LoR group and 43 (56%) patients in the InR group did not receive RAI treatment. Thirty-eight (35%) and 22 (29%) patients in LoR and InR groups received ablative (30–50 mCi) RAI therapy, respectively. In LoR group 5 (4.6%) patients and in InR group 12 (16%) patients received 100 mCi or more RAI activity. Only one patient in the InR group recurred during follow-up. No statistically significant difference regarding local recurrence was found between patients who didn’t receive RAI or were treated with RAI within both LoR (p=0.152) and InR (p=0.272) groups.
Conclusion: There is consensus for LoR patients about omitting RAI therapy after surgery. Indications for RAI treatment in InR DTC are still under debate. RAI use based on EDRA seems to be a better option than decisions solely made on histopathological risk factors and decreases adjuvant high-activity RAI use without increasing recurrence risk.

Erken Dinamik Risk Tabakalandýrmasý ATA Düþük ve Orta Riskli Papiller Tiroid Kanserli Hastalarda Ablatif ve Adjuvan Radyoiyot Kullaným Oranýný Azaltýr

Amaç: Diferansiye tiroid karsinomunda (DTC) radyoaktif iyot (RAI) genellikle remnant ablasyonu veya adjuvan tedavi amacýyla kullanýlmaktadýr. Orta risk (InR) grubu hastalar için RAI kararý halen tartýþma konusudur. Bu çalýþmanýn amacý, düþük riskli (LoR) veya InR olarak sýnýflandýrýlan papiller tiroid kanseri (PTC) hastalarýnda erken postoperatif risk deðerlendirmesinin RAI kullanýmýna etkisini analiz etmektir.
Gereçler ve Yöntemler: Bu, tek merkezli, prospektif bir kayýt çalýþmasýdýr. Ocak 2012 ile Aðustos 2021 tarihleri arasýnda ameliyat edilen ve LoR veya InR olarak sýnýflandýrýlan 186 hasta bu çalýþmaya dahil edildi. Tüm hastalara ayný endokrin cerrah tarafýndan total tiroidektomi (TT) ve santral lenf nodu diseksiyonu (CLND) uygulandý. Her hastaya ameliyattan sonra altýncý haftada boyun ultrasonografisi (US), serum tiroglobulin (Tg) ve anti-tiroglobulin (Anti-Tg) düzeylerinden oluþan bir erken dinamik risk deðerlendirmesi (EDRA) yapýldý. Hastalarýn çoðu ya RAI uygulanmadan izlendi ya da önceden belirlenmiþ kriterlere göre ablatif düþük aktivite (30-50 mCi) RAI aldý.
Sonuçlar: Medyan takip süresi 63 ay idi. LoR grubundaki altmýþ altý (%61) hasta ve InR grubundaki 43 (%56) hasta RAI tedavisi almadý. LoR ve InR gruplarýndaki sýrasýyla otuz sekiz (%35) ve 22 (%29) hasta ablatif (30-50 mCi) RAI tedavisi aldýlar. LoR grubunda 5 (%4.6) hasta ve InR grubunda 12 (%16) hasta 100 mCi veya daha fazla RAI aktivitesi ile tedavi edildiler. InR grubundan sadece bir hastada takip sýrasýnda nüks geliþti. LoR (p=0,152) ve InR (p=0,272) gruplarýnda RAI almayan veya RAI ile tedavi edilen hastalar arasýnda lokal nüks açýsýndan istatistiksel olarak anlamlý bir fark bulunmadý.
Çýkarýmlar: LoR hastalarýnda ameliyattan sonra RAI tedavisinin verilmemesi konusunda uzlaþma vardýr. InR DTC’de RAI tedavisi endikasyonlarý halen tartýþýlmaktadýr. EDRA'ya dayalý RAI kullanýmý, yalnýzca histopatolojik risk faktörlerine göre verilen kararlardan daha iyi bir seçenek gibi görünmektedir ve nüks riskini artýrmadan adjuvan yüksek aktivite RAI kullanýmýný azaltmaktadýr. (SETB-2023-06-105)