Clinical outcome of image-guided adaptive radiotherapy in the treatment of lung cancer patients

Figures & data

Table I. Patients- and tumour characteristics.

Patients (n)	ART-group (52)	No-ART-group (52)
Age (years) median (range)	63 (43–82)	67 (40–83)
Sex
Male	24	34
Female	28	18
Diagnosis
NSCLC	38	38
SCLC	14	14
Histology NSCLC
Adenocarcinoma	25	23
Squamous-cell carcinoma	13	15
Performance status WHO
0–1	41	48
2	11	4
Clinical stage
I–IIB	4	8
IIIA	31	20
IIIB	16	21
IV	1	3
Pre-existing comorbidity ^a
Yes	26	25
No	26	27
Smoking status
Smoker	24	17
Previous smoker	28	35
Never smoker	0	0
FEV1 (percentage predicted) median (range)	73.5 (33–118)	75.0 (28–129)
Concurrent chemotherapy
Yes	38	39
No	14	13

^aCharlson Comorbidity Index. FEV1, forced expiratory volume at one second; NSCLC, non-small cell lung cancer; PS, performance status; RT, radiotherapy; SCLC, small cell lung cancer; WHO, World Health Organisation.

Table II. Margins and dosimetric characteristics.

Patients (n)	ART-group (52)	No-ART-group (52)	p-Value^a
GTV-CTV	5 mm	5 mm
Respiration	Included in the GTV delineation	Accounted for in CTV-PTV margin
CTV-PTV on N-site	9 mm (10 in C-C)	10 mm (13 in C-C)
CTV-PTV on T-site	4 mm (5 in C-C)	10 mm (13 in C-C)
RT-dose, NSCLC (Gy)
Median (range)	66 (60–66)	66 (50–66)
RT-dose, SCLC (Gy)
Median (range)	45 (−)	45 (45–46)
MLD (Gy)
Mean (range)	12.6 (3.3–19.4)	14.4 (4.1–20.1)	0.03
GTV (cm3)
Mean (range)	98.3 (12.5–369.3)	107.6 (4.2–509.5)	0.6
PTV (cm3)
Mean (range)	400.5 (89.6–1321.1)	598.6 (125.1–1398.0)	< 0.001

^at-test. C-C, cranio-caudal; CTV, clinical target volume; Gy, Gray; GTV, gross tumour volume; MLD, mean lung dose; NSCLC, non-small cell lung cancer; PTV, planning target volume; RT, radiation therapy; SCLC, small cell lung cancer.

Figure 1. Loco-regional progression in lung cancer patients treated with curative chemo-radiotherapy with an adaptive strategy (ART-group) and without an adaptive strategy (No-ART-group). A) Actuarial analysis of the time to loco-regional progression compared for the two groups. B) The 12-months distribution of loco-regional failures in tumour site (T-site), lymph node site (N-site) or both is exposed for the two groups.

Figure 2. Analysis of all loco-regional failures occurring in lung cancer patients (n = 104) treated with radiotherapy with an adaptive strategy (ART) or without an adaptive strategy (No-ART). Failures were analysed with regards to GTV-T and GTV-N as delineated on the planning CT. Recurrences lying outside GTV-T and/or GTV-N were evaluated with regards to the vicinity to the 95% isodose line of the treatment plan. This was done to detect incidences of marginal failure, defined as failure within 2 cm of the 95% isodose line. Patients who developed recurrence in T- and N-site simultaneously were analysed separately on T- and N-site.

Figure 3. Incidences of severe pneumonitis (grade ≥ 3) in lung cancer patients treated with curative chemo-radiotherapy with an adaptive strategy (ART-group) and without an adaptive strategy (No-ART-group).