surveillance CT scan after resection of NSCLC
- related: lung mass and cancer
- tags: #literature #boards
Guidelines recommend surveillance with a chest CT scan for recurrence of non–small cell lung cancer treated with curative intent 6 months after completion of therapy.
Surveillance after curative intent surgical resection may include imaging and bronchoscopy. Most guidelines suggest a chest CT scan every 6 months for the first 2 years after treatment and yearly after that through 5 years. The evidence suggesting an outcome benefit from this protocol is weak, and the same protocol is recommended whether the cancer was a small stage I cancer or a stage III (N2) cancer treated with multimodality therapy. There is no evidence available to support the use of PET imaging or tumor marker monitoring, and PET imaging would add cost and radiation exposure (low-dose chest CT involves approximately 1.5-3 mGy; diagnostic CT, 5-10 mGy; and, PET-CT, 10-15 mGy). Bronchoscopy may be added if central airway squamous cell cancers have been treated or if resection margins are very small, such as <5 mm. Imaging intervals for surveillance after stereotactic body radiation therapy are less well defined. Postradiation imaging changes can be difficult to separate from tumor progression.
Separately, the probability of a new primary lung cancer is higher in those who have had lung cancer than in those who have not, independent of other risk factors. As the probability of recurrence wanes, surveillance imaging may be considered screening for a second primary lung cancer. Although the risk of a secondary primary lung cancer (approximately 2% per year on average) is high enough to consider screening, the ability to tolerate evaluation and treatment of a second lung cancer is impacted by prior treatment received. Thus, it is unclear whether the balance of benefit and harms favors screening this population. Decisions may be made on an individual level whether to continue surveillance beyond the 5-year mark.1