Radiotherapy in the management of non‐small‐cell lung cancer

Abstract

Radiation plays an important role in the management of patients with non-small-cell carcinoma of the lung. Understanding the impact of radiation on this tumor and on normal tissues requires a knowledge of the natural history of the tumor, and of basic sciences, including radiation physics and biology. This review gives a brief outline of the scientific basis of radiotherapy, followed by a discussion of some practical issues concerning radiation tolerances of tissues within the thorax, the acute and late sequelae of radiation, and the treatment planning process. The role of radiotherapy is explored in the following settings: Radical radiation with curative intent for early stage disease, adjuvant mediastinal irradiation for completely resected tumors, radiation of known residual disease after surgical resection, preoperative radiation, prophylactic cranial radiation, radiation of locally advanced unresectable disease, and, finally, radiation with palliative intent in patients with metastatic disease. Pertinent studies, with the emphasis on randomized trials, are outlined to document the present state of understanding with respect to the impact of radiation in each of these situations. Several of the controversies in this area are addressed, with particular emphasis on selection of patients for high-dose radiation and recent results of combined modality treatment with radiation and chemotherapy.

Redox Gene Therapy Protects Human IB-3 Lung Epithelial Cells Against Ionizing Radiation-Induced Apoptosis

“…Therefore, any sttategy to protect nontumor lung tissue from ionizing irradiation and allow for higher total doses could greatly improve the efficacy of this tteatment. The clinical pathology of ionizing irradiation is subdivided into acute cellular damage that occurs during and immediately after radiation and late inflammatory responses, which lead to chronic lung fibrosis (Bezjak and Payne, 1993). Such fibrosis is the most life-threatening aspect of radiation injury.…”

“…Lungs are particularly sensitive to ionizing irradiation with a Td 5/5 (total dose that produces 5% complications after 5 years) of 18-22 Gy (Bezjak and Payne, 1993). This dose is two-to three-fold lower than for other tissues such as skin, ttachea, heart, and spinal cord, which are also affected during the course of thorax radiation (Bezjak and Payne, 1993). Therefore, any sttategy to protect nontumor lung tissue from ionizing irradiation and allow for higher total doses could greatly improve the efficacy of this tteatment.…”

Die Resektion von Bronchialkarzinomen mit simultaner Lungenvolumenreduktion bei terminalem Lungenemphysem

“…Therapeutische Alternativen mit kurativer Intention zur Resektion des Bronchialkarzinomes existieren nicht. Infolge strahlentherapeutischer Maûnahmen ist mit einer nicht kalkulierbaren zunehmenden Einschränkung der Lungenfunktion durch Strahlenfibrose und Pneumonitis zu rechnen, so dass das Risiko der Induktion einer klinisch therapierefraktären respiratorischen Insuffizienz besteht [27]. Auch die Chemotherapie kann lediglich als Palliation angesehen werden.…”

Lobectomy Combined With Volume Reduction For Patients With Lung Cancer And Advanced Emphysema

“…Thus limited pulmonary function in patients represents as much a management problem for the radiation oncologist as for the surgeon. 4 This dilemma is further compounded for surgeons by the lack of a precisely definable point at which the risk-to-benefit ratio for resection becomes unfavorable, particularly in light of improvements in the anesthetic, surgical, and postoperative treatment of patients with advanced emphysema.…”