Background and Objectives: The purpose of this study was to systematically review literatures on active surveillance for low-risk differentiated thyroid cancer, and to evaluate risk factors for tumor size increase during active surveillance.Subjects and Method We conducted a systematic review and a meta-analysis of studies reporting on tumor growth during active surveillance of papillary thyroid cancer. Using the MEDLINE and EMBASE databases, we searched studies published from the inception of database to December 2020. Studies were included if reported on at least one clinical risk parameter in addition to reporting on the change in tumor size during active surveillance. Results: Out of 33 studies screened, seven were included in the meta-analysis. The odds ratio of a temporal size increase of more than 3 mm in papillary thyroid cancer was 0.011 person-years (95% confidence interval [CI]: 0.009 to 0.013). The odds ratio of lymph node metastasis was 0.002 person-years (95% CI: 0.001 to 0.003). Younger age was a significant risk factor for tumor growth during active surveillance, with a standardized median difference of -0.63 (95% CI: -1.00 to -0.27). In the three studies that evaluated the association of thyroid-stimulating hormone levels and tumor size, the results were contradictory. Conclusion Active surveillance may be used more cautiously for younger patients.

Background and Objectives: Bilateral microphones with contralateral routing of signal (BiCROS) hearing aid is an option for hearing rehabilitation in individuals with asymmetric sensorineural hearing loss (ASNHL). The clinical factors influencing the trial and purchase of BiCROS were investigated. Subjects and Methods: We reviewed the medical records of 78 patients with ASNHL who were recommended to use BiCROS and analyzed the demographic and audiological factors influencing the trial and purchase of BiCROS. Results: Among the 78 patients, 52 (66.7%) availed of the free BiCROS trial and 21 (26.9%) purchased BiCROS. The mean pure tone audiometry (PTA) air conduction (AC) threshold of the better- and worse-hearing ears were 44.2±12.8 dB and 90.7±22.5 dB HL, respectively. The decision for trial or purchase of BiCROS was not influenced by age, sex, duration of hearing loss of the worse-hearing ear, or PTA AC threshold or speech discrimination score of both ears. The first and third quartiles of the PTA AC thresholds for the better-hearing ear of BiCROS buyers were 38.75 dB and 53.75 dB HL, respectively. The counterpart values for the worse-hearing ear were 72.50 dB and 118.75 dB HL, respectively. Conclusions The clinical factors analyzed in this study were found to be irrelevant to the trial and purchase of BiCROS in patients with ASNHL. Nevertheless, the distribution range of the auditory thresholds of the subjects using BiCROS can be a useful basis for the counseling of patients with ASNHL and selection of candidates for BiCROS use.