Strategies for management of isolated lung nodules (NCCN 2015 Lung Cancer Screening + Fleischner Society) 2015-08-21 Oncology News With the popularity of low-dose spiral CT screening, the detection rate of isolated lung nodules has increased significantly. How to identify the benignity or malignancy of lung nodules and the choice of follow-up time for considering benign nodules are the thorny issues clinicians are currently facing. There are currently many important reference standards for the management of pulmonary nodules, but no consensus has been reached on each standard. In this article, we describe the management strategy of isolated lung nodules by combining the NCCN 2015v1 guidelines for lung cancer screening and the Fleischner Society. The NCCN guidelines and the Fleischner Society screening population selection Both guidelines recommend routine screening for high-risk groups. High-risk groups are defined as those aged 55-74 years, who smoke at least 30 packs per year, and who are currently smoking or have not quit smoking for more than 15 years. Different guidelines consistently recommend that routine screening is not recommended for people who have quit smoking more than 15 years ago and have no other risk factors. Screening for people who smoke more than 30 packs per year, are 55 years of age or older and have a family history of tumors can lead to early detection of lung cancer lesions. Second, the management strategy of isolated lung nodules. 2.1 Fleischner’s principles of management 2.1.1 Principles of management of solid lung nodules: Solid nodules ≤ 4 mm in diameter, low risk population, no need for follow-up; high risk population, follow-up should be performed at month 12, if follow-up results show stable nodules, no further follow-up is needed. Solid nodules 4-6 mm in diameter should be followed up at month 12 for low-risk individuals and at month 6-12 for high-risk individuals, and again at month 18-24 if the nodule is stable. For solid pulmonary nodules 6-8 mm, the low-risk group should be followed up once at 6-12 months and once at 18-24 months if there is no change; the high-risk group should be followed up once at 3-6 months and once at 18-24 months if there is no change. For nodules >8 mm in diameter, enhanced CT, PET/CT, or puncture examinations were performed at 3, 9, and 24 months regardless of risk factors. In addition, it is important to note that: (i) the follow-up period should be shortened for patients with a previous history of tumor. ②People under 35 years of age with less than 1% incidence of lung cancer and radiosensitivity should be cautious when applying CT follow-up. ③When inflammatory lesions are considered, the follow-up time should be shortened after anti-inflammatory treatment. ④Small lesions with intra-focal calcification are mostly suggestive of benign lesions. ⑤ The possibility of malignancy of lesions larger than 8 mm is 10-20%, and treatment should be actively taken. 2.1.2 Principles of management of non-solid pulmonary nodules: Pure ground glass density nodules ≤5 mm in diameter do not require follow-up. The reason for this recommendation is that these nodules are mostly atypical adenomatous hyperplasia, with stable nodule size and usually no change over several years. For purely ground glass nodules >5 mm in diameter, a review of CT at 3 months is recommended, and if the nodule is unchanged, a review of CT once a year for at least 3 years. For non-solid nodules, if the solid component is >5 mm, a CT review is recommended at 3 months, and if there is no change in the nodule, a biopsy or surgical excision is performed. If the solid component is <5mm, it is recommended to review CT every 3 months, and if the nodule has not changed, review CT once a year for at least 3 years. For some solid nodules >10mm consider PET-CT. The main reasons for the first review recommendation of 3 months are: (i) both pure ground glass nodules and partially solid nodules may disappear after a short follow-up. ②Short-term follow-up also ensures early detection of rapidly enlarging nodules and appropriate management at an early stage. 2.2 Principles of lung cancer NCCN 2015v2 screening guideline management 2.2.1 Principles of solid or partially solid nodule management: For nodules less than 6 mm in diameter, LDCT annually for 2 years. For nodule diameter 6-8mm, LDCT is repeated after 3 months, no change in nodule size, LDCT is repeated after 6 months, still no change then LDCT is repeated after 12 months, after that LDCT is repeated every year for 2 years. Nodule diameter >8mm, consider PET/CT examination, if low level lung cancer is suspected, follow up, follow up principle is consistent with nodule diameter 6-8mm. High grade lung cancer, biopsy or surgical resection. In all the above cases if nodule growth is found at follow-up, surgical resection is recommended. 2.2.2 Principles of management of non-solid nodules: nodule diameter <5mm, review CT after 12 months, no change in nodule size, annual LDCT examination for 2 years. Diameter 5-10mm, review CT after 6 months, no change, LDCT every year for 2 years. Diameter >10mm, review LDCT after 3-6 months, if stable, LDCT can be reviewed after 6-12 months, or biopsy or surgical resection. In all the above cases, if the nodule is found to be enlarged or the non-solid nodule is transformed into solid nodule during the follow-up, surgical resection should be performed, except for those with diameter <5mm, which can be considered for dynamic review of LDCT in 3-6 months. Similarities and differences between the NCCN guidelines and Fleischner The two guidelines mainly refer to the results of the NLST trial, and the data are mainly from the E-ELCAP and NELSON trials. Although the target populations for which LDCT screening is indicated are very similar between the different societies, there are many differences in the follow-up of positive results. For isolated pure ground glass shadows >5 mm the Fleischner guidelines suggest that follow-up should be performed at 3 months of detection to clarify their persistence, followed by 1 CT review per year for at least 3 years. the NCCN guidelines recommend 6 months of follow-up, followed by annual CT review for 2 years. The Fleischner, NCCN guidelines are essentially similar in their recommendations for CT follow-up of larger, partially solid pulmonary nodules. However, there is still controversy between the two regarding the risk of screening. IV. Summary The different guidelines provide reliable evidence-based medical evidence for clinicians on the management of isolated pulmonary nodules, but it is difficult to reach agreement because different guidelines refer to different evidence-based medical evidence. It is expected that higher-level clinical evidence will refine and improve these guidelines in the future, so that the diagnosis and management of isolated pulmonary nodules will enter the era of precision.