Megavoltage equipment (linear accelerator or cobalt) is the most effective. Local control of tumor is improved if a boost to a limited area of the primary is used. A new technique, hyperfractionation, where irradiation is given twice per day, is under investigation.
Prophylactic radiation to the central nervous system (whole brain irradiation) is administered for cases which are free of central nervous system symptoms or which have negative brain imaging prior to brain irradiation (also called prophylactic cranial irradiation--PCI). PCI is not usually used for non-small cell lung cancers, but may be useful in extending symptom-free quality of life for small cell cancer patients, if not actually increasing survival.
Radiation therapy in combination with multi-drug chemotherapy results in better survivals than radiation therapy alone or chemotherapy alone for limited stage small cell cancer patients. For extensive disease, supplementary chest irradiation does not appear to improve survival when compared to combination chemotherapy alone.
To learn more about radiation therapy, see the Cancer Treatment module.