Modern radiotherapy techniques and progress in non-small cell lung cancer


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Suresh Senan1
1VU University Medical Center, Asterdam, The Netherlands

Abstract

Stereotactic ablative lung radiotherapy (SABR) is now established as a standard of care in some countries for patients with a peripheral stage I NSCLC who are unfit to undergo surgery. SABR precisely delivers very high radiation doses in a very short period of time (often 60Gy in only 3-8 fractions). Reported local tumor control rates exceed 90% for tumors measuring ≤5 cm. The results of outpatient SABR contrasts with results of conventional radiotherapy using doses of at least 50-60Gy, for which local failure rates of 40-50% have been reported. A study assessing the impact of introducing SABR in one Dutch province (population 3 million) revealed a reduction in the proportion of untreated elderly patients, an improvement in overall survival that was limited to those undergoing SABR, but no change in survival for patients undergoing surgery [Palma D, JCO 2010].

In stage III-N2 NSCLC, concurrent CT-RT is the recommended standard of care. However, population-based studies show that the percentage of patients who undergo any combination of CT-RT can be low as 25%. Reasons that are cited to account for a failure to use concurrent CT-RT include (i) clinicians who consider that a majority of patients in their routine practice do not represent the patients treated within clinical trials, and (ii) acceptance of the ill-defined concept ‘disease that is too extensive to be encompassed within a radical radiotherapy volume [O’Rourke N, Cochrane Database Syst Rev. 2010]. Recent clinical data challenging these assumptions will be presented, including results of patient selection based on a patient’s fitness to receive cisplatin-based chemotherapy [Phernambucq E, Ann Oncol 2011].

Five-year survivals for lung cancer vary almost two-fold between Western European countries, with survival differences seen mainly within the first few months of treatment [Holmberg L, Thorax 2010]. Population-wide implementation of the abovementioned advances can improve survival further.