Evaluation of tolerance and toxicity of high-dose-rate brachytherapy boost combined with interstitial hyperthermia for prostate cancer

Figures & data

Table 1. Patient characteristics.

Age (years)
Median	67.5
Range	52–78
Initial tumour stage (number of patients)
T1b – t1c	27
T2a-t2c	42
T3a-t3b	7
Initial PSA level (ng/mL)
Median	14
Range	1.36–199.4
Initial Gleason score
≤ 6	22
7	34
≥8	20
Initial risk group according to NCCN [60]
Low	2
Intermediate	31
High	43

PSA, prostate-specific antigen; NCCN, National Compreensive Cancer Network.

Table 2. Criteria for acceptance of HDRBT treatment plans.

DVH parameter	Recommended value	Acceptable value
CTV D90	>95%	>90%
CTV V200	<15% (optimally lowest)
Urethra Dmax	<120% (optimally lowest)
Rectum Dmax	<85% (optimally lowest)
Since 2012
CTV D90	>100%	>95%
CTV V100	>95%	>90%
CTV V200	<10%	<15%
Urethra D0.1cm^3	<115%
Urethra Dmax	<120%	<125%
Rectum D0.1cm^3	<80%
Rectum D2cm^3	<65%
Rectum Dmax	<85%

DVH: dose-volume histogram; PTV: planned target volume.

Table 3. Hyperthermia (IHT) parameters.

Parameter/value	Mean	Median	Range
Time of IHT procedure (min)	54.2	51.0	15.0–60.0
PTV
T maximum (°C)	42.4	42.1	40.4–45.6
CEM43 °C (min)	12.5	6.0	1.0–57.0
Rectum
T average (°C)	38.4	38.7	36.4–40.8

IHT, interstitial hyperthermia; PTV, planned target volume.

Table 4. Dose–volume histogram parameters of HDRBT.

Parameter/value	Mean	Median	Range
Number of catheters	16.0	16.0	11.0–23.0
Prostate volume (cm^3)	34.8	32.2	17.6–73.7
PTV (%)
D90	99.2	99.0	93.5–105.2
V100	89.3	89.6	84.4–94.2
V150	30.3	30.0	20.6–43.2
V200	8.5	8.2	4.7–14.2
Urethra (%)
D0.1cm^3	112.0	112.0	106.6–118.4
D10	110.1	109.8	99.2–116.7
Rectum [%]
D0.1cm^3	77.7	77.6	72.4–81.8
D2cm^3	60.8	61.0	52.5–68.7

PTV, planned target volume.

Table 5. Acute complications of HDRBT boost combined with IHT (N = 76). Median follow-up time 26.3 months.

Toxicity	G0 (%)	G1 (%)	G2 (%)
Nocturia	8/76 (10.5)	40/76 (52.6)	28/76 (36.9)
Frequency	29/76 (38.2)	29/76 (38.2)	18/76 (23.6)
Obstruction	32/76 (42.2)	26/76 (34.2)	18/76 (23.6)
Retention	50/76 (65.9)	18/76 (23.6)	8/76 (10.5)
Non-infectious cystitis	45/76 (59.2)	26/76 (34.2)	5/76 (6.6)
Haematuria	29/76 (38.2)	47/76 (61.8)	0/76 (0.0)
Incontinence	70/76 (92.1)	5/76 (6.6)	1/76 (1.3)
Pain (hypogastric, penile, perineal)	69/76 (90.8)	7/76 (9.2)	0/76 (0.0)
Urgency	35/76 (46.0)	29/76 (38.2)	12/76 (15.8)
Rectal bleeding	76/76 (100.0)	0/76 (0.0)	0/76 (0.0)

Toxicity was assessed according to Common Terminology Criteria for Adverse Events, version 4.

Table 6. Procedure-related adverse events.

Toxicity	Number of patients	%
Post-lumbar puncture headache	1	1.3
Anal canal discomfort	2	2.6

Toxicity was assessed according to Common Terminology Criteria for Adverse Events, version 4.

Table 7. Late toxicities of HDRBT combined with IHT (N = 59). Median follow-up time 29.7 months (range 18.4–43.0).

Toxicity	G0 (%)	G1 (%)	G2 (%)	G3 (%)
Nocturia	6/59 (10.2)	39/59 (66.1)	14/59 (23.7)	0/59 (0.0)
Frequency	29/59 (49.1)	21/59 (35.6)	9/59 (15.3)	0/59 (0.0)
Obstruction	36/59 (61)	16/59 (27.1)	7/59 (11.9)	0/59 (0.0)
Retention	40/59 (67.8)	14/59 (23.7)	5/59 (8.5)	0/59 (0.0)
Non-infectious cystitis	47/59 (79.7)	11/59 (18.6)	1/59 (1.7)	0/59 (0.0)
Haematuria	55/59 (93.2)	2/59 (3.4)	2/59 (3.4)	0/59 (0.0)
Incontinence	54/59 (91.5)	5/59 (8.5)	0/59 (0.0)	0/59 (0.0)
Pain (hypogastric, penile, perineal)	57/59 (96.6)	2/59 (3.4)	0/59 (0.0)	0/59 (0.0)
Urgency	39/59 (66.1)	12/59 (20.3)	8/59 (13.6)	0/59 (0.0)
Rectal bleeding	56/59 (94.9)	3/59 (5.1)	0/59 (0.0)	0/59 (0.0)
Diarrhoea	57/59 (96.6)	2/59 (3.4)	0/59 (0.0)	0/59 (0.0)
Stool incontinence	58/59 (98.3)	1/59 (1.7)	0/59 (0.0)	0/59 (0.0)
Stool urgency	56/59 (94.9)	3/59 (5.1)	0/59 (0.0)	0/59 (0.0)

G0, ?; G1, ?; G2, ?; G3, ?.