The impact of regional nodal radiotherapy (dose/volume) on regional progression and survival in unresectable non-small cell lung cancer: an analysis of RTOG data.
OBJECTIVE
To evaluate in-field progression and survival of patients with unresectable non-small cell lung cancer (NSCLC) in relation to adequacy of coverage of thoracic regional nodal areas in the radiotherapy volume.


METHODS
A total of 1705 patients from four large RTOG trials (78-11, 79-17, 83-11 and 84-07) were analyzed for this purpose. For each of these trials, the dose delivered to nodal regions was recorded and an assessment of adequacy of field borders was made. Each nodal site was assessed for progression, defined as in-field or out-of-field. In patients who had adequate borders on nodal regions, the results were analyzed according to the dose delivered.


RESULTS
The majority (74%) of patients were between the age of 55-75. Forty-six percent of the patients had KPS of 60-80 and 52% had KPS of 90-100. Sixty percent of patients had a weight loss of less than 5% in the 6 months prior to diagnosis. Deviations from the protocol in field borders (borders not per protocol) were most frequent for the contralateral hilum (25.2%) and least frequent in the ipsilateral hilum (6.3%). The adequacy of ipsilateral hilar coverage was important for preventing the in-field progression (11.6 vs. 22% for adequately vs. inadequately covered ipsilateral hilum, respectively, P=0.01), however, did not influence the 2-year-survival (35 vs. 37%) or median survival (1.3 vs. 1.1 year). Neither the in-field progression nor the 2-year-survival were affected by adequacy of nodal coverage in the mediastinum, ipsilateral supraclavicular area and contralateral hilum, even when different doses were analyzed.


CONCLUSIONS
These data suggest that elective irradiation of mediastinal, contralateral hilar and supraclavicular lymph nodes may not be necessary in the treatment of unresectable NSCLC.
Emami
Bahman
B
Department of Radiation Oncology, Loyola University Medical Center, 2160 S. First Avenue Building 105, Rm 2994, Maywood, IL 60153, USA. bemami@lumc.edu
Mirkovic
Nena
N
Scott
Charles
C
Byhardt
Roger
R
Graham
Mary V
MV
James Andras
E
E
John
Madhu
M
Herskovic
Arnold
A
Urtasun
Raul
R
Asbell
Sucha O
SO
Perez
Carlos A
CA
Cox
James
J
D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D008198:Lymph Nodes / Q000528:radiation effects*; D015182:Lymphatic Irradiation; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000532:radiotherapy; D009367:Neoplasm Staging; D011829:Radiation Dosage; D016032:Randomized Controlled Trials as Topic; D016019:Survival Analysis; D013909:Thorax; D016896:Treatment Outcome