Clinical performance evaluation of O-Ring Halcyon Linac: A real-world study

Table 1 Clinical characteristics

Characteristics	Number (n)	Percent (%)
Median age (yr)	59
Age range (yr)	26-82
Sex
Male	33	54
Female	28	46
Treatment area
Head and neck	12	20
Chest	13	21
Abdomen	10	16
Pelvic	14	23
Spine and bone	12	20
Treatment type
Primary tumour	34	56
Recurrence in situ	1	1
Metastasis	26	43
Radiation technology
IMRT	21	35
VMAT	39	64
SRT	1	1
Concurrent therapy
Chemotherapy	15
Other1	15
No	31
Radiation toxicities
No	23	38
Cured after treatment	34	56
Yes	4	6

¹Targeted therapy/immunotherapy/endocrine therapy.

IMRT: Intensity modulated radiotherapy; VMAT: Volumetric modulated arc therapy; SRT: Stereotactic radiotherapy.

Table 2 Response evaluation and time interval for evaluation

Group	The time interval for evaluation (n)			Response evaluation (n)
	1 mo	2 mo	3 mo	CR	PR	PD	SD
Head and neck	6	4	2	5	3	1	3
Chest	7	6	0	0	4	3	6
Abdomen	6	4	0	0	2	0	8
Pelvic	13	1	0	11	2	0	1
Spine and bone	5	6	1	0	1	3	8
Total	37	21	3	16	12	7	26

CR: Complete response; PR: Partial response; PD: Progressive disease; SD: Stable disease.

Table 3 mean ± SD values of treatment delivery parameters (and range)

Dosimetric verification	Point dose measurements (%)	ArcCHECK (2%/2 mm) (%)	ArcCHECK (3%/3 mm) (%)	Portal dosimetry (2%/2 mm) (%)
Head and neck	0.26 ± 1.1 (-0.22-1.92)	95.5 ± 1.8 (93.2-97.7)	99.4 ± 0.5 (98.8-100)	97.8 ± 2.4 (93.3-100)
Chest	1 ± 0.6 (0.45-2.18)	97.63 ± 1.1 (96.1-98.4)	99.2 ± 0.8 (97.9-100)	89.7
Abdomen	1.11 ± 0.7 (0.23-2.01)	97.1 ± 2.0 (95.5-99.3)	98.8 ± 1.5 (96.5-99.7)	96
Pelvic	-0.15 ± 0.7 (-0.99-1.38)	96.0 ± 2.2 (94.2-99.2)	99 ± 1.4 (96.3-100)	98.4 ± 2.4 (98.1-98.6)
Spine and bone	0.2 ± 1.8 (-1.8-2.72)	96.5 ± 1.8 (93.6-97.8)	99.2 ± 0.9 (97.9-100)	93.2 ± 6.4 (88.6-97.7)
Total	0.42 ± 1 (-1.8-2.72)	96.4 ± 1.8 (93.3-99.3)	99.1 ± 1.1 (96.3-100)	96.7 ± 3.4 (88.6-100)