Outcomes Following Stereotactic Body Radiotherapy with Intensity-Modulated Therapy versus Three-Dimensional Conformal Radiotherapy in Early Stage Non-Small Cell Lung Cancer

Figures & data

Table 1 Patient Characteristics According to Treatment Modality at Time of Initially Treated Lesion with Stereotactic Body Radiation Therapy (n=297)

Characteristic	3DCRT (N=155)		IMRT (N=142)		p Value
	n	%	n	%
Age, median	69	–	72.5	–	0.027
Sex					0.931
Male	80	51.9	74	52.1
Female	75	48.4	68	47.9
ECOG PS					0.150
0–1	109	70.3	94	66.2
2–3	35	22.6	45	31.7
Unknown	11	7.1	3	2.1
Indication					0.453
Inoperable	104	67.1	101	71.1
Refused	41	28.9	41	28.9

Table 2 Tumor Characteristics According to Treatment Modality for Each Lesion Treated with Stereotactic Body Radiation Therapy (n=351)

Characteristic	3DCRT (n=177)		IMRT (n=174)		p Value
	n	%	n	%
Biopsy Proven					0.003
Yes	169	95.5	148	85.1
No	8	4.5	26	14.9
Pathology					0.029
Adenocarcinoma	94	55.6	76	51.4
Squamous	49	29.0	61	41.2
NSCLC NOS	26	15.4	11	7.4
T Stage (7^th Ed)					0.500
T1a	129	72.9	117	67.2
T1b	34	19.2	42	24.1
T2a	14	7.9	15	8.6
Tumor Size (max dimension)					0.431
< 1 cm	28	15.8	17	9.8
1 – 2 cm	90	50.8	94	54.0
2 – 3 cm	42	23.7	43	24.7
> 3 cm	17	9.6	20	11.5
Location					0.271
RUL/RML/LUL	109	61.6	117	67.2
RLL/LLL	68	38.4	57	32.8

Table 3 Treatment Details (n=351)^†

	3DCRT (n=177)		IMRT (n=174)		*P Value
	n	%	n	%
Advanced Respiratory Management					<0.0001
Yes	47	26.6	9	5.2
No	130	73.4	165	94.8
Treatment Machine					<0.0001
21-EX	140	79.1	7	4.0
Tomotherapy	4	2.3	149	85.6
TrueBeam	3	1.7	17	9.8
VERO	30	16.9	1	0.6
Prescription Dose (Total Gy/number of fractions)					<0.0001
60/3	32	19.5	4	2.6
54/3	40	24.4	29	18.7
48/4	70	44.3	88	55.7
50/5	11	6.7	30	19.4
Other	11	5.1	4	3.6
Dosimetry^† Available	164	92.6	155	89.0
Median Prescription Isodose Line	91% (range 73.3–100%)		100%**
Mean GTV Dose (% of Rx)	107.7		103.6		<0.0001
Mean PTV Dose (% of Rx)	101.5		101.2		0.89
Maximum Point Dose (% of Rx)
Mean	111.8%		106.5%		<0.0001
<105%	44	26.8	66	42.6	N/A
105–109.99%	31	18.9	56	36.1
110–114.99%	39	23.7	28	18.1
115–119.99%	22	13.4	3	1.9
120–124.99%	6	3.7	0	0
125–129.99%	12	7.3	0	0
130–134.99%	5	3.0	0	0
135–139.99%	5	3.0	2	1.3

Notes: *Calculated from individual generalized linear mixed models taking into account the presence of multiple lesions per person. **All IMRT plans were prescribed to 100% Isodose Line except two patients (89.3% and 90.5%). ^†Complete Dosimetry data available for 274 subjects, 319 lesions.

Figure 1 Freedom from to local failure according to treatment modality with either three-dimensional radiotherapy (3D) or intensity-modulated radiotherapy (IMRT).

Figure 2 Freedom from local failure for the entire patient cohort.

Figure 3 Overall survival according to treatment modality with either three-dimensional radiotherapy (3D) or intensity-modulated radiotherapy (IMRT).

Figure 4 Overall survival for the entire patient cohort.

Table 4 Cox Proportional Hazard Model Assessing Overall Survival (n=297); Adjusted hazard Ratios (AHR) and 95% Confidence Intervals (CI)

Predictor Variables	AHR	(95% CI)	P Value
Age, years	1.03	(1.01–1.05)	0.001
Sex
Female	0.74	(0.52–1.06)	0.099
Male	1.00	Reference
Respiratory Motion Management
Gating or Tracking	0.72	(0.44–1.19)	0.20
All Phases	1.00	Reference
Treatment Modality
3DCRT	1.04	(0.71–1.54)	0.83
IMRT	1.00	Reference
Lesions Treated
Multiple	0.55	(0.33–0.90)	0.017
Single	1.00	Reference
Maximum Diameter (cm)	1.17	(1.00–1.37)	0.048