ESTRO 2024 - Abstract Book

S1637

Clinical - Lung

ESTRO 2024

Results:

Between November 2021 and March 2023, 48 eligible patients were accrued in the study and 42 were evaluable for the primary endpoint. Squamous cell histology was commonest (48%) followed by adenocarcinoma (42%); other histologies included small cell (8%) and sarcomatoid carcinoma.

Primary disease staging was T3 or T4 in 29% and 31% patients respectively; 48% patients had N2 and 21% had N3 disease. Tumour laterality was equally distributed: 52% right and 48% left sided.

The average volumes of primary and nodal gross tumour volumes were 133cc and 37cc respectively; mean planning target volume was 554.5cc (range 119-1199cc).

Eight patients (17%) received platinum-based doublet neoadjuvant chemotherapy. All patients were treated with volumetric modulated arc therapy (VMAT) to a total dose of 60Gy in 30 fractions over 6 weeks. Forty-two patients received concurrent chemotherapy (either weekly Paclitaxel-Carboplatin or three-weekly Cisplatin-Etoposide). Average total lung volume was 2636cc; mean lung dose to lungs minus PTV was 11.9Gy (range 1-18Gy). Lung volumes receiving 5Gy, 10Gy and 20Gy were 59%, 41% and 20% respectively on an average. Mean heart dose was 12Gy (range 1-28Gy); heart volume receiving 30Gy and 40Gy were 19Gy and 15Gy. PFD was tolerated well, with no drug related adverse events noted during and after the course of administration. At 3-months follow-up, the change in parameters of pulmonary function tests are shown in table 1. The absolute change in FEV1, FVC, FEV1/FVC ratio and DLCOsb values at 3-month from baseline were 0.10L, -0.06L, 3.4% and - 1.19L respectively.

Table 1. Pulmonary function test parameters Parameter Baseline

3-months post RT

Mean (±SD)

Median

IQR

Mean (±SD)

Median

IQR

FEV1 in L

1.80 (0.60)

1.68

1.27-2.41

1.81 (0.51)

1.92

1.34 2.24 55.5 78.6 1.92 2.94 61.3 80.4 70.2 80.9

in %

64.3 (18.5)

64.40

48.1-77.4

67.29 (17.5)

68.40

FVC in L

2.47 (0.72)

2.39

1.91-3.02

2.42 (0.65)

2.38

in %

71.18 (15.3)

68.25

59.8-84

71.1 (15.3)

71.6

FEV1/FVC ratio

72.14 (9.2)

72.8

65.7-78.7

75.02 (8.5)

75.39

DLCOsb in L

5.71 (1.41)

5.79

4.88-6.55

4.62 (1.25)

4.74

3.70 5.55

in % 49.8 67.3 FEV1: Forced expiratory volume in 1s; FVC: Forced vital capacity; DLCOsb: Diffusion lung capacity for Carbon Monoxide; SD: Standard deviation; IQR: Inter-quartile range 70.95 (16.55) 72.70 56.9-82.1 60.43 (13.7) 62.00