Efficacy and its predictor in microwave ablation for severe secondary hyperparathyroidism in patients undergoing haemodialysis

Figures & data

Figure 1. The parathyroid nodule presents a hypoechoic signal before MWA (A). The ablation needle was inserted into the parathyroid tissue under ultrasound guidance (B).

Table 1. Comparison between the two groups regarding possible predictors.

Possible predictors	Response group	No response group	t/χ^2 value	P value
Age (years)	57.58 ± 6.49	53.11 ± 11.53	−1.224	0.231
Dialysis age (months)	86.17 ± 39.83	92.00 ± 48.09	0.35	0.728
Mean powers of MWA (W)	32.92 ± 5.82	33.16 ± 4.78	0.126	0.901
Maximum diameter of parathyroid (cm)	1.44 ± 0.46	1.72 ± 0.73	1.153	0.258
No. of parathyroid nodules (per person)	2.25 ± 1.06	2.37 ± 1.01	0.312	0.757
No. of parathyroid nodules ablated (per person)	2.00 ± 1.13	2.00 ± 0.88	2.123	0.547
Baseline level of iPTH (pg/mL)	1270.58 ± 401.03	1674.89 ± 346.01	2.981	0.006

Figure 2. ROC curve for iPTH predicting MWA efficacy for severe SHPT.

Table 2. Baseline characteristics of the study patients arranged by treatment group.

	MWA group (N = 18)	PTX group (N = 12)	P-value
Age (years)	57.06 ± 9.14	57.17 ± 8.03	0.97
Sex ratio (male:female)	4:13	6:6	0.27
Dialysis age (months)	90.33 ± 46.08	106.33 ± 43.55	0.35
Underlying nephrology causes			0.49
Chronic glomerulonephritis	9 (50%)	7 (58.3%)
Diabetic nephropathy	4 (22.2%)	1 (8.3%)
Hypertensive nephropathy	1 (5.6%)	2 (16.7%)
Autosomal dominant polycystic kidney disease	1 (5.6%)	1 (8.3%)
Drug-induced kidney damage	0	1 (8.3%)
Gouty nephropathy	1 (5.6%)	0
Unknown	2 (11.1%)	0

*Percentages in parentheses unless indicated otherwise.

Table 3. Patient and treatment characteristics arranged by treatment group.

	MWA group (N = 12)	PTX group (N = 18)	P-value
Size of parathyroid nodules
Maximum diameter (cm)	1.23 ± 0.48	1.47 ± 0.81	0.10
Minimum diameter (cm)	0.78 ± 0.29	0.76 ± 0.42	0.74
No. of parathyroid nodules (per patient)	2.28 ± 0.96	3.92 ± 0.52	<0.001
No. of parathyroid nodules removed/ablated (per patient)	2.22 ± 1.00	3.58 ± 0.79	<0.001
Power used in the MWA (W)	32.22 ± 2.56	NA	NA
Surgical procedure	NA		NA
Total PTX		6
Subtotal PTX		2
Total PTX with autotransplantation		4

N, number of participants in the group; NA, not applicable.

Figure 3. Characteristics of changes in iPTH levels arranged by treatment group. Rates of achieving the recommended goals (A) and changes in serum iPTH levels (B) arranged by treatment group. Percentage of serum iPTH levels lower than 124 pg/mL (lower limit of the target range) (C) and higher than 558 pg/mL (upper limit of the target range) (D) arranged by treatment group. *P < 0.05, compared with the PTX group. Base, baseline; w, week; m, month.

Figure 4. Rates of achieving recommended goals for serum calcium and phosphorus levels arranged by treatment group. Base, baseline; w, week; m, month.

Figure 5. Changes in serum iPTH and alkaline phosphatase levels in participants with persistently low iPTH. Base: baseline; w: week; m: months.