Five- and seven-year outcomes for image-guided moderately accelerated hypofractionated proton therapy for prostate cancer

Figures & data

Table 1. Patient and treatment characteristics.

Characteristics	Very low risk	Low risk	Favorable intermediate risk	Unfavorable intermediate risk	Overall
Total number of patients	89	185	161	147	582
Median age, years (range)	65.2 (46.1–78.1)	65.1 (47.7–81.5)	66.4 (41.1–83)	66.4 (49.1–83.8)	65.7 (41.1–83.8)
T stage
T1	82	143	109	78	412
T2a	6	36	34	37	113
T2b	1	5	16	28	50
T2c	0	0	2	4	6
T2?	0	1	0	0	1
Gleason score
<6	89	185	32	2	308
7 = 3 + 4	0	0	129	66	195
7 = 4 + 3	0	0	0	79	79
Prostate-specific antigen
Median (Range)	4.6 (0.8–9.6)	5.9 (0.7–9.9)	5.8 (0.3–19.6)	6.4 (2.1–19.6)	5.7 (0.3–19.6)
<10	89	185	134	119	527
10 to <20	0	0	27	28	55
Dose
<70 GyRBE	5	0	1	1	7
70 GyRBE	84	179	35	42	340
72.5 GyRBE	0	6	125	104	235
>72.5 GyRBE	0	0	0	0	0
Androgen deprivation therapy	3	2	3	13	21

Figure 1. Overall survival at 7 years stratified by disease risk.

Figure 2. Freedom from biochemical relapse at 7 years stratified by disease risk.

Figure 3. Freedom from distant metastases at 7 years stratified by disease risk.

Figure 4. EPIC scores and scales for specific questions regarding fecal incontinence and rectal bleeding over time.

Table 2. Literature review.

Reference N	No. of Pts overall and by risk group	Modality	Dose/Fractionation	Median follow-up	4-Year FFBP	5-Year FFBP	7-Year FFBP	10-Year FFBP	Late grade 2 GI toxicity	Late grade 3 GI toxicity	Late grade 3 GU toxicity
Protons or IMRT 70–72.5 GyRBE/28–29
Present series	582	Protons	70–72.5 GyRBE/28–29	8.0 years		96.80%	95.20%		9.9% and 11.2% at 5 and 7 yrs (CTCAE v4.0)	1.4% and 1.4% at 5 and 7 yrs (CTCAE v4.0)	1.3% and 2.1% at 5 and 7 yrs (CTCAE v4.0)
	LR- 274					98.80%	98.80%
	FIR- 161					97.20%	95.20%
	UIR- 147					93.10%	88.80%
University of Pennsylvania (12)	184	Protons	70 GyRBE/28	4.1 years	93.50%				13.6% at 4 yrs (CTCAE v4.0)	0.5% at 4 yrs (CTCAE v4.0)	0.0% at 4 yrs (CTCAE v4.0)
	LR- 18				94.40%
	FIR- 78				92.50%
	UIR- 88				93.80%
NRG oncology /RTOG (2)	1092, all LR	20% for 3DCRT and 80% for IMRT		5.8 years
			70 Gy/28 (550 patients)			86.30%			18.3% at 5 yrs (CTCAE v3.0)	4.1% at 5 yrs (CTCAE v3.0)	3.5% at 5 yrs (CTCAE v3.0)
Cleveland clinic (4)	770	IMRT	70 Gy/28	3.75 years					3.1% at 5 yrs (RTOG)	1.3% at 5 yrs (RTOG)	0.1% at 5 yrs (RTOG)
	LR- 262					95.00%
	IR- 216					85.00%
Cleveland clinic (13)	854	IMRT	70 Gy/28	11.3 years						1.2% and 1/2% at 5 and 10 yrs (CTCAE v4.03)	1.3% and 1.7% at 5 and 10 yrs (CTCAE v4.03)
	LR- 266					96.00%		88.00%
	FIR- 238					86.00%		78.00%
	UIR- 106					82.00%		71.00%
Protons- 78–82 GyRBE/39–41
UFHPTI (11)	171 of 211	Protons	78–82 GyRBE/39–41	5.2 years						0.5% at 5 yrs (CTCAE v4.0)	1% at 5 yrs (CTCAE v4.0)
	LR- 89					99.00%
	IR- 82					98.00%
UFPTI (16)	1098 of 1327	Protons	78–82 GyRBE/39–41 (98% of pts)	5.5 years						0.6 at 5 yrs (CTCAE v4.0)	2.9% at 5 yrs (CTCAE v4.0)
	LR- 547					99.00%
	IR- 551					94.00%

3DCRT: 3-dimensional conformal radiation therapy; CTCAE: Common Terminology Criteria for Adverse Events; FFBP: freedom from biochemical progression; FIR: favorable intermediate risk; IMRT: intensity-modulated radiation therapy; LR: low risk; IR: intermediate risk; RTOG: Radiation Therapy Oncology Group; UFHPTI: University of Florida Health Proton Therapy Institute; UIR: unfavorable intermediate risk.

Data availability statement

The authors agree to share the data upon reasonable request by researchers.