A metaanalysis of thoracic radiotherapy for small cell lung cancer. - Pignon,J.P.; Arriagada,R.; Ihde,D.C.; Johnson,D.H.; Perry,M.C.; Souhami,R.L.; Brodin,O.; Joss,R.A.; Kies,M.S.; Lebeau,B. (N Engl J Med, 1992)