ARRS 2022 Abstracts

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E1689. Unlocking the Mystery of Systemic Therapies in Treatment of Lung Cancer
Authors
  1. Anitha Kini; The Ottawa Hospital
  2. Hamid Bayanati; The Ottawa Hospital
  3. Elena Pena; The Ottawa Hospital
  4. Carole Dennie; The Ottawa Hospital
  5. Carolina Souza; The Ottawa Hospital
Background
Advanced lung cancers (stages III and IV) are treated with systemic therapy, including chemotherapy and molecular targeted therapy. It is essential that radiologists are able to assess not only response to treatment on CT of the chest but also to recognize the spectrum of complications of systemic therapy in the lungs. The purpose of this educational exhibit is to describe the CT appearances of pulmonary drug-induced toxicity in patients treated with systemic therapy for lung cancer.

Educational Goals / Teaching Points
This exhibit aims to review basic principles of systemic treatment of lung cancer, including the role of chemotherapy and recent molecular target therapies, and review CT imaging findings related to post-systemic therapy treatment.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Lung toxicity can occur early (less than 2 months) or late (more than 2 months). Early onset chemotherapy-related lung toxicity includes inflammatory interstitial pneumonitis, pulmonary edema, and less commonly, acute pulmonary syndrome. Late onset chemotherapy-related lung toxicity is pulmonary fibrosis, most commonly seen with bleomycin treatment. Molecular targeted therapy reduces or inhibits proliferative activity in cancer cells by blocking specific enzymes responsible for cancer growth and proliferation. These more recent treatments for lung cancer can cause a spectrum of pulmonary complications that include pneumonitis, cryptogenic organizing pneumonia, eosinophilic pneumonia, diffuse alveolar damage, sarcoid like granulomatosis and lymphadenopathy, pulmonary hemorrhage, pulmonary embolism, and pulmonary edema. Typical response patterns to systemic drug therapy on CT includes decrease in tumor size and vascularity and sometimes, cavitation. Atypical response patterns include increase in the size of the mass with decreased metabolism and presence of intralesional and/or perilesional hemorrhage with stable or increased mass size, which is seen as pseudo progression after immunotherapy.

Conclusion
Newer drugs are being used for treatment of advanced lung cancers. It is essential to assess the response to treatment and identify complications associated with these treatments. PET-CT has the ability to assess tissue viability and detect metastatic lesions when used in conjunction.