Fatal Radiation Pneumonitis - Literature Review and Case Series

• Published in: Advances in radiation oncology Vol. 5; no. 2; pp. 238 - 249
• Main Authors: Keffer, Stephen, M.D, Guy, Christopher L., Ph.D, Weiss, Elisabeth, M.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2020; Elsevier
• Subjects: Hematology, Oncology, and Palliative Medicine; Thoracic Cancer
• ISSN: 2452-1094; 2452-1094
• DOI: 10.1016/j.adro.2019.08.010

AbstractPurposeFatal radiation pneumonitis is a rare event. In recent years, higher incidences of grade 5 pneumonitis have been reported. Based on three cases in our clinic, a literature review was performed to assess specific clinical features and risk factors for fatal pneumonitis. Materials and MethodsThree patients with non small cell lung cancer were treated with conventionally fractionated radiotherapy, two with volumetric modulated arc therapy and one with intensity modulated radiotherapy. All three patients had high volumes of 5 Gy in the total lung and contralateral lungs. Patients died from pneumonitis between two and five months following the end of radiotherapy. A literature review focused on grade 5 pneumonitis was performed for conventionally fractioned and stereotactic radiotherapy for lung cancer. ResultsPatients with grade 5 pneumonitis develop symptoms sooner than lower grade pneumonitis. Symptoms often do not respond to steroid treatment or return after steroid taper. Imaging features extend beyond the high dose area and involve the contralateral lung. Dosimetric risk factors include both low dose and high dose lung volumes. For patients undergoing stereotactic radiotherapy interstitial lung disease has been described as a risk factor. DiscussionDespite decades of investigating radiation pneumonitis, the question of the optimum dose distribution in the lung – a large dose to a small volume versus a small dose to a large volume - is still unresolved. When both low and high dose lung volume constraints are followed, the risk for grade 5 pneumonitis has been shown to be low even with IMRT and concurrent chemotherapy. In addition to dose factors, underlying clinical and radiographic parameters play an important role for the development of grade 5 pneumonitis.