Shahzad Ahmad, Muhammad Zeshan Sadiq, Muhammad Ismail Amer, Maheen Salman, Arhum Hamid, Sheryar Irfan, Sean Nikravan
This single-centre retrospective cohort represents an initial North American experience of outpatient RFA for ATA low-risk PTC. The findings suggest RFA is a feasible minimally invasive option in appropriately selected patients, demonstrating substantial short-term tumor volume reduction. No early complications were observed in this cohort. However, given the limited sample size, retrospective design, and restricted long-term follow-up, further prospective multicenter studies are required to better define long-term efficacy and oncologic outcomes.
BACKGROUND: Radiofrequency ablation (RFA) has emerged as a minimally invasive alternative to surgery for selected patients with papillary thyroid carcinoma (PTC). However, North American data on outpatient endocrinologist performed RFA for PTC remains limited. This study evaluated the efficacy and safety of outpatient RFA in a United States outpatient clinic setting.
OBJECTIVE: To evaluate the feasibility, short-term tumor volume response and safety profile in an outpatient RFA for low-risk PTC in a United States outpatient clinic setting.
METHODS: A retrospective observational study of a non-comparative clinical cohort, conducted on 22 patients, consisting of 18 females and 4 males with cytologically confirmed PTC who underwent single-session outpatient RFA under local anesthesia and mild conscious sedation between 2021 and 2023. RFA was performed using 18-gauge electrodes with a 0.5 cm active tip. Serial ultrasounds were used to assess PTC lesion volume reduction.
RESULTS: The mean overall PTC volume reduction at the 12-month mark was 71%. Interval specific longitudinal analysis revealed the following volume reduction rate: 3 months, 27.4% volume reduction; 6 months, 72.5% volume reduction; 9 months, 80.6% volume reduction; and 12 months, 87.5% volume reduction. Average longitudinal VRR for BRAF-positive tumors (n=4) showed a 77.05% mean volume reduction compared to 72.3% in BRAF-negative tumors (n=18). Interval-specific volume reduction in T1a tumors (n=12) revealed: 3 months, 55.4% volume reduction; 6 months, 89% volume reduction; 9 months, 74% volume reduction; 12 months; 89% volume reduction. Whereas volume reduction in T1b tumors (n=9) revealed: 3 months, 60.14% volume reduction; 6 months, 79.5% volume reduction; 9 months, 77% volume reduction; 12-month, 85.66% volume reduction. The single T2 case displayed 19% volume reduction at 3 months and 67% at 9 months follow-up. 3 patients achieved a complete lesion disappearance on ultrasound via extended follow-up of 36 months.
CONCLUSION: This single-centre retrospective cohort represents an initial North American experience of outpatient RFA for ATA low-risk PTC. The findings suggest RFA is a feasible minimally invasive option in appropriately selected patients, demonstrating substantial short-term tumor volume reduction. No early complications were observed in this cohort. However, given the limited sample size, retrospective design, and restricted long-term follow-up, further prospective multicenter studies are required to better define long-term efficacy and oncologic outcomes.