Survival and prognostic factors of pulmonary oligometastases treated with stereotactic body radiotherapy

Figures & data

Table 1. Patient characteristics (N = 206).

Characteristics		Percentage
Age (median, range)
<70 years	68 years (28–87)	63.1%
≥70 years		36.9%
Gender
Male	121	58.7%
Female	85	41.3%
Comorbidity index
CCI (median, range)	1 (0–13)
Score 0	73	35.4%
Score 1–2	68	33.0%
Score ≥3	65	31.6%
CIRS (median, range)	1 (0–13)
Score 0–4	177	85.9%
Score ≥5	29	14.1%
Primary tumor location
Colorectal	118	57.3%
Lung (Non small cell)	36	17.5%
Melanoma	11	5.3%
Sarcoma	10	4.9%
Breast	7	3.4%
Others	24	11.6%
Presentation of metastasis
Synchronous	58	28.2%
Metachronous	148	71.8%
Distribution of metastasis
Lung only	120	57.2%
Extrapulmonary and lung	86	41.8%
Number of Metastases
In body
a. Single	52	25.4%
a. ≥2	154	74.8%
In lungs
a. Single	90	43.7%
a. ≥2	116	56.3%
Pre-SBRT Chemotherapy
Yes	99	48.1%
No	107	51.9%

SBRT, CCI, CIRS.

Figure 1. Overall survival for inoperable pulmonary oligometastases treated with SBRT.

Figure 2. (A) Overall survival for synchronous and metachronous oligometastases (B) Overall survival for colorectal and non colorectal primary tumors.

Table 2. Prognostic factors univariate analysis.

	Covariate	Median OS months (95% CI)	HR (95%CI)	p-value
1	Age
	<70 years (128)	37.2 (29.6–44.7)	0.73 (0.50–1.06)	.104
	≥70 years (78)	30.9 (25.0–36.8)
2	Sex
	Male (121)	38.9 (30.7–47.1)	0.83 (0.57–1.21)	.334
	Female (85)	29.8 (23.1–36.5)
3	Primary location
	Colorectal (118)	39.2 (34.8–43.6)	0.64 (0.44–0.92)	.018
	Others (88)	27.5 (20.6–34.4)
4	Timing of metastasis
	Synchronous (58)	40.5 (34.4–46.6)	0.59 (0.38–0.92)	.019
	Metachronous (148)	28.8 (21.3–36.5)
5	Number of metastases in body
	Single (52)	34.0 (20.6–47.4)	0.96 (0.63–1.48)	.874
	Multiple (154)	32.8 (25.3–40.3)
6	Number of metastases in lungs
	Single (90)	31.3 (20.2–42.0)	1.06 (0.72–1.55)	.775
	Multiple (116)	33.4 (26.4–40.4)
7	Location of metastasis
	Lung only (120)	31.1 (24.4–37.8)	1.14 (0.77–1.68)	.515
	Extrapulmonary (86)	39.0 (28.5–49.5)
8	PreSBRT chemotherapy
	No (107)	32.8 (23.8–41.8)	1.34 (0.92–1.94)	.129
	Yes (99)	39.0 (29.6–48.4)
9	Biological equivalent dose (BED10)
	≥100 (144)	34.0 (26.3–41.7)	0.77 (0.53–1.13)	.183
	<100 (62)	30.9 (18.9–42.9)
10	Fractionation of SBRT
	Fractionated (188)	33.4 (26.0–40.7)	1.09 (0.58–1.84)	.923
	Single (18)	30.8 (10.1–51.6)
11	Tumor size
	<3 cm (144)	34.0 (26.3–41.7)	0.72 (0.49–1.05)	.092
	≥3 cm (62)	29.5 (20.8–38.1)
12	Delay in initiation of SBRT
	≥4 months (132)	32.8 (24.0–41.6)	0.87 (0.60–1.28)	.482
	<4 months (74)	33.0 (24.9–41.1)
13	Charlson comorbidity index
	0 (73)	34.0 (16.5–51.5)
	1–2 (68)	33.0 (20.8–45.2)	0.76 (0.47–1.22)	.254
	≥3 (65)	32.8 (19.6–46.0)	0.95 (0.61–1.48)	.829
14	Cumulative illness rating scale
	0–4 (177)	33.4 (27.1–39.6)	0.93 (0.55–1.56)	.781
	≥5 (29)	30.9 (14.9–46.9)
15	Location of lung metastasis
	Central (76)	33.4 (24.2–42.6)	1.03 (0.70–1.50)	.881
	Peripheral (130)	32.8 (21.2–44.4)
16	Location of lung metastasis
	Lower lobe (120)	33.4 (25.4–41.4)	1.14 (0.77–1.67)	.515
	Other lobes (86)	31.1 (20.8–41.4)

SBRT/OS/HR/95% CI.

Table3. Prognostic factors on multivariable analysis.

	Covariate	HR (95%CI)	p-value
1	Primary location
	Colorectal (118)	0.62 (0.42–0.89)	.011
	Others (88)
2	Timing of metastasis
	Synchronous (58)	0.56 (0.36–0.86)	.009
	Metachronous (148)
3	Tumor size
	<3 cm (144)	0.68 (0.46–0.99)	.046
	≥3 cm (62)

Figure 3. Overall survival of synchronous liver oligometastases that later developed pulmonary oligometastases, synchronous pulmonary oligometastases, and metachronous pulmonary oligometastases.

Figure 4. (A) Overall survival in synchronous versus metachronous oligometastases from colorectal primary site (B) Overall survival in synchronous versus metachronous oligometastases from non colorectal primary site.