Does microwave interstitial hyperthermia prior to high-dose-rate brachytherapy change prostate volume or therapy plan parameters?

Figures & data

Table 1. Treatment characteristics.

	All patients (N = 60)	No hyperthermia (N = 30)	Hyperthermia (N = 30)
HDRBT monotherapy	14	14	0
EBRT and HDRBT boost	30	15	15
HDRBT salvage	16	1	15

EBRT, external beam radiotherapy; HDRBT, high-dose-rate brachytherapy.

Table 2. Mean values of prostate volume parameters for patients treated with radical intent (N = 44) and patients treated with salvage intent (N = 16). All errors are standard deviations (SD) around the mean.

	Radical treatment (N = 44)	Salvage treatment (N = 16)	p Value
VP volume (cm^3)	33.12 ± 11.8	29.89 ± 8.5	0.32
LP volume (cm^3)	42.50 ± 12.8	38.21 ± 10.9	0.24
PP volume (cm^3)	43.93 ± 12.9	40.31 ± 11.4	0.33
volume change (%)	3.63 ± 4.8	5.55 ± 5.4	0.19
volume change (cm^3)	7.58 ± 3.4	6.54 ± 4.7	0.34

LP, live plan; PP, post plan; VP, virtual plan.

Table 3. Mean values of treatment plan parameters, based on live plan and post plan dose–volume histograms (DVH) for all patients (N = 60), for patients treated without-hyperthermia (N = 30), and for patients treated with hyperthermia (N = 30). All errors are standard deviations (SD) around the mean.

	All patients (N = 60)				No hyperthermia (N = 30)				Hyperthermia (N = 30)
DVH parameter	Live plan	Post plan	Mean change	p Value	Live plan	Post plan	Mean change	p Value	Live plan	Post plan	Mean change	p Value
Prostate volume (cm^3)	41.4 ± 12.4	43 ± 12.5	1.6	< 0.05	41.6 ± 8.5	43.1 ± 8.8	1.5	<0.05	41.1 ± 15.5	42.8 ± 15.5	1.7	<0.05
PTV/prostate
Dmean (%)	141.6 ± 3.6	136.2 ± 6.1	−3.8	<0.05	140.1 ± 3.4	136.2 ± 3.7	−2.8	<0.05	143.1 ± 3.1	136.2 ± 7.9	−4.8	<0.05
D90 (%)	102.6 ± 2.6	96.7 ± 6.1	−5.7	<0.05	103.0 ± 2.2	98.0 ± 5.6	−4.8	<0.05	102.2 ± 2.9	95.3 ± 6.3	−6.6	<0.05
V100 (%)	92.1 ± 2.1	86.9 ± 6.5	−5.6	<0.05	92.5 ± 1.7	88.7 ± 4.1	−4.1	<0.05	91.7 ± 2.3	85.0 ± 7.8	−7.2	<0.05
V150 (%)	29.4 ± 4.3	25.4 ± 5.1	−13.0	<0.05	27.3 ± 3.9	24.6 ± 3.6	−9.7	<0.05	31.5 ± 3.7	26.3 ± 6.2	−16.3	<0.05
V200 (%)	8.1 ± 1.7	7.0 ± 1.8	−13.2	<0.05	7.3 ± 1.9	6.6 ± 1.4	−10.0	<0.05	8.8 ± 1.6	7.4 ± 2.1	−16.5	<0.05
Urethra
Dmax (%)	116.8 ± 2.4	120.8 ± 17.2	3.5	0.07	116.5 ± 2.5	118.3 ± 14.2	1.6	0.49	117.1 ± 2.4	123.3 ± 19.6	5.3	0.09
Dmean (%)	96.0 ± 6.5	94.1 ± 7.5	−1.8	<0.05	95.3 ± 6.6	94.0 ± 6.5	−1.3	<0.05	96.6 ± 6.4	94.3 ± 8.5	−2.4	<0.05
D0.1cm3	113.4 ± 2.0	111.6 ± 5.8	−1.6	<0.05	112.7 ± 1.9	111.8 ± 3.3	−0.8	0.11	114.1 ± 1.8	111.4 ± 7.7	−2.3	0.06
Rectum
Dmax (%)	82.3 ± 4.7	85.2 ± 10.1	3.6	<0.05	81.4 ± 2.5	84.9 ± 8.9	4.4	<0.05	83.1 ± 6.0	85.4 ± 11.4	2.8	0.21
Dmean (%)	46.4 ± 4.3	46.7 ± 4.4	0.8	0.64	46.0 ± 3.8	46.7 ± 3.2	1.9	0.20	46.9 ± 4.8	46.6 ± 5.4	−0.2	0.75
D2cm3	59.1 ± 4.1	59.0 ± 5.9	0.0	0.93	59.2 ± 4.1	59.3 ± 4.8	0.3	0.79	59.0 ± 4.1	58.8 ± 6.9	−0.3	0.82

DVH, dose–volume histogram; PTV, Planning Target Volume.