Hypofractionated Radiotherapy in Non Small Cell Lung Cancer: A Review of the Current Literature

Beli      I.; Koukourakis      G.; Platoni      K.; Tolia      M.; Kelekis      N.; Kouvaris      J.; Syrigos      C.; Mystakidou      K.; Varveris      C.; Kouloulias      V.

doi:10.2174/157488710791233608

Abstract

Hypofractionated irradiation has an established role in the palliative treatment of patients with advanced medically inoperable non - small cell lung cancer (NSCLC) and poor performance status. Also hypofractionated radiotherapy merits careful consideration in the curative treatment of patients with Stage I and II disease using contemporary technology. The biological effect of radiation on tumours is increased as the overall treatment time is shortened. Hypofractionated field radiotherapy offers acceptable palliation with minimal toxicity. The rates of palliation for hemoptysis, chest pain, cough and dyspnea reported from studies with very short regimen (8,5 Gy x 2), are comparable to those of other trials that used more protracted palliative treatment. The observed toxicity is minimal, and no cases of oesophagitis, pneumonitis, or radiation myelopathy developed. The minimal toxicity is a reflection of both the low biologic total dose and the tight RT design. Therefore the radiation side effects appear to be related to the technique of RT delivered rather than the patients PS. Hence, widely believed dogmas concerning the tolerance of critical structures to conventionally fractionated doses, such as the dose-volume effect, total dose, and time (latency) dependency, has to be re-evaluated for hypofractionated radiation therapy. As well there is data suggesting that the small stages I — II NSCLC are likely to benefit from hypofractionated regimens too. Hypofractionated stereotactic radiotherapy is a new technically complex approach to the treatment of early-stage nonsmall cell lung cancer. It is capable to deliver much higher doses to the cancer than is possible with standard techniques, and as a result, rates of tumour control are high and similar to what can be achieved by surgical resection. Refinements of technique and dose as well as randomized data are required before stereotactic radiotherapy can be endorsed as a standard of care for patients with inoperable peripherally located T1 non small cell lung cancer. A clear advantage of the very short hypofractionated palliative regimen is that it allows patients with a short expected survival time to spend more of their remaining time away from the hospital.

Keywords: Hypofractionation, radiotherapy, lung cancer, review