Safety and Efficacy of Intensity-Modulated Stereotactic Body Radiotherapy Using Helical Tomotherapy for Lung Cancer and Lung Metastasis

Table 2

Tumor characteristics.

Characteristic	Number of tumors
	Total	4 fractions	5–8 fractions	𝑃 value
Total number of tumors	72	37	35
Histology*
Primary
Squamous	2	1	1
Adeno	10	6	4
Small	1	1	0
Metastasis
Squamous	2	0	2
Adeno	3	1	2
Small	1	1	0
UD	1	1	0
Recurrence
Squamous	2	0	2
Adeno	4	3	1
Maximum tumor diameter (mm), median [range]	15 [6–32]	14 [8–30]	15 [6–32]	0.12
CTV (cc), median [range]	2.2 [0.2–32]	1.6 [0.2–18]	2.8 [0.2–32]	<0.001
PTV (cc), median [range]	9.1 [0.8–65]	6.9 [0.8–41]	14 [1.6–65]	0.001
PTV D95 (%), median [range]	100 [88–100]	100 [88–100]	100 [95–100]	0.14
CI, median [range]	1.0 [0.8–1.0]	1.0 [0.8–1.0]	1.0 [0.8–1.0]	0.87
HI, median [range]	1.2 [1.1–1.7]	1.2 [1.1–1.7]	1.2 [1.0–1.7]	0.145
MLD (Gy), median [range]	1.9 [0.2–8.1]	1.7 [0.4–5.6]	2.6 [0.2–8.1]	0.076
Volume of lung (cc), median [range]	3064 [1952–5278]	3057 [1952–5278]	3071 [1957–4700]	0.32

∗Patients with no histological diagnosis are not included.
UD: undifferentiated; CTV: clinical tumor volume; PTV: planning target volume; CI: conformity index; HI: homogeneity index; MLD: mean lung dose.