Comparative analysis of laser thermotherapy and cryotherapy efficacy in the treatment of retinoblastoma of peripheral localization

Purpose. To evaluate the efficacy of laser thermotherapy (TT) and cryotherapy (CT) in the treatment of retinoblastoma of peripheral localization in standardized groups using comparative analysis. Material and methods. Comparative analysis of laser TT and CT was performed in two independent groups, which were standardized according to the main clinical characteristics: patients’ age at the time of treatment (p = 0.13), gender (p = 0.27), tumor height (p = 0.18) and largest basal diameter (p = 0.71), tumor stage (p = 0.31), previous chemotherapy type (p = 0.15) and the follow-up (p = 0.11). After standardization, the laser TT group consisted of 59 patients (61 eyes, 191 tumors); the CT group consisted of 57 patients (61 eyes, 87 tumors). Results. A comparative analysis of local tumor control rate in the groups of laser TT and CT showed statistically significant difference (p < 0.0001), calculated by chi-squared test: in laser TT group local tumor control was achieved in 88% of cases (n = 168), tumor progression/recurrence was observed in 11.5% cases (n = 23). In the CT group complete local control was achieved in 52% of cases (n = 45), incomplete regression with additional treatment was detected in 23% of cases (n = 20). Tumor progression/recurrence was observed in 25% of cases (n = 22) after CT. The incidence of complications also significantly differed depending on the method of local treatment (p = 0.012), calculated according to the Fisher’s exact test. There was no significant difference in the eye retention rate: 97% — in the TT group and 90% — in the CT group (p = 0.27), calculated according to the Fisher’s exact test. Conclusion. Thermotherapy is a highly effective approach in the treatment of retinoblastoma of peripheral localization and demonstrates higher local tumor control rate compared to CT (88 and 75%, respectively), lower complications rate (1.5 and 15%) and comparative eye retention rate (97 and 90%).