Overview
What the Name Means
Radiation pneumonitis (RP) is the inflammatory, subacute phase of radiation induced lung injury after thoracic radiotherapy.
Radiation pneumonitis (RP) is the inflammatory, subacute phase of radiation-induced lung injury after thoracic radiotherapy. It is not an immediate radiation reaction and does not mean that pulmonary fibrosis has already developed. RP generally appears within 6 months of treatment, often after a period when the patient seemed to be recovering. The later fibrotic phase usually develops after 12 months. These phases are not separated by a precise boundary; inflammation and fibrosis can overlap. The clinical problem is easy to underestimate because the symptoms resemble common complications of cancer treatment: pneumonia, pulmonary embolism, heart failure, tumour progression, an exacerbation of chronic obstructive pulmonary disease (COPD) or interstitial lung disease (ILD), and drug-related pneumonitis. RP is therefore a clinical-radiologic diagnosis of exclusion.