Table 1. Characteristics of the Included Studies.
| Study | Enrollment Period | Affiliation | Study Design | Criteria for Enrollment (Summary of Inclusion and Exclusion Criteria)* | Comparison | Surgery | Thermal Ablation | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pt. (Tumor) | Age† | M:F | Pt. (Tumor) | Age† | M:F | ||||||
| Xu et al. [23] | January 2012–October 2017 | Fudan University Affiliated Shanghai Fifth People's Hospital, China | Retro. | Inclusion: PTMC by US-guided FNAB, away from the thyroid capsule (> 2 mm), no abnormality of contralateral thyroid gland, no lymph node metastasis, ultrasound imaging had a clear needle path; Exclusion: severe heart/lung disease, condition intolerable of surgery, rejected surgery, treatment anxiety | Surgery vs. MWA | 46 (46) | 46.2 | 16:30 | 41 (41) | 45.1 | 12:29 |
| Li et al. [22] | January 2013–September 2018 | Beijing Friendship Hospital, China | Retro. | Inclusion: solitary PTMC by US-guided FNAB, away from the thyroid capsule, no gross extra-thyroidal extension, no lymph node metastasis, no history of neck irradiation; Exclusion: other than PTC, lymph node metastasis, distant metastasis, pregnancy, coagulation disorder, severe heart/respiratory/liver/renal failure, follow-up loss, incomplete information | Surgery vs. MWA | 143 (143) | 49.2 | 29:114 | 168 (168) | 47.4 | 36:132 |
| Zhou et al. [25] | January 2014–December 2014 | Rui Jin Hospital, China | Retro. | Inclusion: solitary PTMC by US-guided FNAB, away from the thyroid capsule (> 3 mm), no massive calcification, normal thyroid function, no lymph node metastasis; Exclusion: other than PTC, coexisting other thyroid nodule with suspicious US feature, with cystic component, multicentricity, lymph node metastasis, distant metastasis, pregnancy, coagulation disorder | Surgery vs. LA | 45 (45) | 41.6 | 17:28 | 36 (36) | 41.5 | 14:22 |
| Zhang et al. [24] | January 2013–November 2013 | General Hospital of Chinese PLA, China | Retro. | Inclusion: solitary PTMC by US-guided CNB, no extra-thyroidal extension, no lymph node metastasis, no distant metastasis, no aggressive histological type; Exclusion: distant metastasis | Surgery vs. RFA | 80 (86) | 44.1 | 20:60 | 94 (94) | 45.4 | 24:70 |
*Xu et al. [23] described enrollment criteria for MWA, while others described enrollment criteria for both surgery and ablation, †Age: mean age of included patients.
CNB = core needle biopsy, FNAB = fine needle aspiration biopsy, LA = laser ablation, M:F = male:female, MWA = microwave ablation, Pt. = number of patients, PTC = papillary thyroid carcinoma, PTMC = papillary thyroid microcarcinoma, Retro. = retrospective, RFA = radiofrequency ablation, US = ultrasonography