3. Results

3.1. Possible predictors of the efficacy of MWA

Investigation of the possible predictors was conducted on 32 patients. The response group had 28 patients while no response groups had the 4 patients. Only statistically significant difference was observed at the baseline serum Ca levels of the two groups (P <0.05). No statistically significant any other differences were observed between the two groups for the rest of the other characteristics which are summarized in Table 2.

3.2. Investigation of the efficacy of predictors for MWA efficacy

Baseline levels of Ca were analyzed by using logistic regression in order to show the predictive role of it as MWA efficacy on PHPT patients. However, the results of univariate logistic regression analysis revealed no statistically significant difference, and a predictive model has not been constructed to show the predictive role of baseline Ca level on the response for the PHPT patients (P =0.071).

3.3. Treatment outcomes and effect

Figure 1 presents the results of the six-month follow up median values for Ca, ALP, P, and PTH values. Investigation of Figure 3 demonstrates that changes in the followed parameters were statistically significant compared to baseline (P <0.001) (Figure 1) in different times. An obvious statistically significant decrease was observed for the median values of Ca (2.9 mmol/L) and PTH (99.50 ng/L) while that of P (0.9 mmol/L) was decreased in 1 day after MWA therapy. On the other hand, no significant change was observed in ALP (82.00 u/L) at 1 day after MWA. A statically significant difference was obtained after one month later in the ALP levels (P <0.001). The detailed results were also summarized in Table 3.

3.4. Side effect of complications

Most patients experienced a slight tingling and pain sensation in the neck, but this was well tolerated without causing interruption or termination of the procedure. Six patients (18.75%) reported transit voice change, but this resolved without any specific treatment within one day. All in all, flexible fiberoptic laryngoscopy examination was normal. This transit complication was attributable to lidocaine which was used for hydrodissection. One case of cellulitis requiring drainage and antibiotics was developed. There were no major complications requiring hospitalization.