1. CT Screening for Lung Cancer: Update 2016
Gordon Teel MD
Thoracic Radiology
Inland Imaging
Spokane, Washington

2. Goal
Provide practical instruction to radiologists, primary care physicians and chest specialists in managing patients with abnormal CT lung screening studies

3. Objectives:
Understand the scientific basis of CT lung cancer screening
Understand Lung-RADS (Lung Imaging Reporting and Data System)
Understand the roles of the radiologist, primary care physician and subspecialists in the management of screening patients

4. Objectives:
Understand the role multidisciplinary decision making in the definitive diagnosis, staging and treatment of suspected lung cancer

5. EDITORIAL COMMENT
We should perform lung cancer screening as cheaply and efficiently as possible, with a minimum of patient morbidity, and with as little utilization of already overburdened service lines (primary care, chest surgery and especially pulmonology) as possible

6. EDITORIAL COMMENT
We should screen lots of people. Lives saved will be determined by number screened. The research model with relatively small patient groups (2000 or less per site), extensive data collection, and high administrative costs is not practical for large scale screening

7. Lung Cancer: Some Facts
220,000 people get lung cancer every year in the U.S.
160,000 die from it
Those with early stage cancer have a reasonable chance of survival
Vast majority of lung cancer advanced stage at presentation

8. Lung Cancer: An Ideal Tumor for Screening?
Common
High mortality
Usually diagnosed at advanced stage
Much lower mortality when diagnosed at early stage
Easily detected on CT at early stage

9. Scientific Basis of Lung Cancer Screening: National Lung Screening Trial
Potential immense expense of mass CT screening led the NIH to sponsor Randomized Controlled Trial
10 year, $240 million study designed and run mainly by thoracic radiologists

10. National Lung Screening Trial
Compared annual CT screening to annual chest x-ray screening
Lung cancer mortality end point
50,000 patients (25,000 each group)
Patients received screening for three years ( ). Mortality was determined through 2010

11. National Lung Screening Trial: Eligibility Criteria
30 plus pack year smokers or former smokers, years of age, did not quit more than 15 years ago
No previous history of lung cancer, no recent chest CT, no signs or symptoms of lung cancer, such as weight loss, no previous lung cancer surgery, not on home oxygen

12. National Lung Screening Trial: Results

13. National Lung Screening Trial: Results
20% less lung cancer mortality in CT screened group compared to CXR screening
True stage shift with fewer numbers of advanced stage cancers in CT screened group
Statistically significant 7% reduction all cause mortality, all of which explained by lung cancer mortality reduction

14. NLST: Strengths
Well designed randomized trial designed to answer a single question: Does low dose CT lung cancer screening lead to a clinically significant reduction in lung cancer mortality (answer: yes)
All care outside of the screening CT occurred in the community setting, so results can be reliably extrapolated to real world patients

15. NLST Limitations
Not designed to find ideal patient population. Maximum risk population screened to lower costs of study
Not designed to fix upper limit of risk reduction. Trial patients only scanned for 3 years. Control group received CXR screen, not current standard of care

16. NLST Limitations
Not designed to evaluate follow-up methods, since care of patients with positive results occurred in community outside of supervision of trial
Not designed to calculate cost benefit
Not designed to clarify risk of overdiagnosis (which indolent tumors can be ignored)

17. Cost Benefit
Within the trial, 3 years of screening correlated with 1 life saved per 300 people screened
Cost per quality adjusted life year estimated at $81,000
Compares with accepted “threshold” for interventions of $100,000 per quality adjusted life year

18. Lung-RADS
To standardize the work-up of lung cancer screening patients, the ACR and Society of Thoracic Radiology developed Lung-RADS (Lung Imaging Reporting and Data System)
Lung-RADS, like BIRADS, ties imaging findings to specific management recommendations and has discrete categories

20. Lung-RADS
Lung-RADS differs from BIRADS in a crucial way. Due to the complexity of lung cancer diagnosis and staging, the end point of lung screening for the radiologist is suggesting the possibility of a cancer in a lesion, not biopsying it.

21. Lung-RADS
Many suspicious lesions are managed initially with a 3 month follow-up scan
Most suspicious lesions are reclassified as low risk after 3 the month scan

22. Lung-RADS
Our initial assumption was that most management would be done by pulmonary medicine
More efficient for primary care and radiology to manage through point of 3 month scan

23. Lung-RADS
Primary care providers are a crucial part of the initial management of suspicious lesions, and they are doing a great job at it

24. Lung-RADS: Low Risk Categories (1,2,3)
Definitely benign (fat, calcium)
Small (less than 8 mm) solid nodules stable or of indeterminate stability
Tiny (less than 6 mm) new solid nodules
Non-solid nodules either new or of indeterminate stability

25. Lung-RADS: Low Risk Categories (1,2,3)
Category 1. No nodules and definitely benign nodules. Rescreen in 1 year
Category 2. Lesions with a very low likelihood of becoming a clinically active cancer due to size or lack of growth. Rescreen in 1 year

26. Lung-RADS: Low Risk Categories (1,2,3)
Category 3. Probably benign finding(s). 6 month low dose CT

27. Lung-RADS: Suspicious Categories (4A, 4B and 4X)
Findings for which additional diagnostic testing and or tissue sampling is recommended

28. Lung-RADS: Suspicious Categories (4A)
Medium (8-14 mm) nodules present on baseline
Small (less than 8 mm) nodules new or growing
Part solid nodules with small (6 or 7 mm) solid component or growing tiny (less than 4 mm) solid component

29. Lung-RADS: Suspicious Categories (4A)
3 month follow-up. PET CT may be used when there is a greater or equal to 3 mm solid component (not a good idea, actually)
Reclassified as 2 if stable on 3 month follow-up
Reclassified as 4B or 4X if grows on 3 month follow-up

30. Lung-RADS: Suspicious Categories (4B)
Large (15 mm or greater) nodules new, growing, or of indeterminate stability
Medium (8-14 mm) nodules new or growing
Part solid nodules with a medium (8 mm or greater) solid component or small (6 or 7 mm) new or growing solid component

31. Lung-RADS: Suspicious Categories (4B)
Chest CT with or without contrast, PET/CT and/or tissue sampling…PET CT may be used when there is a 8 mm or larger solid component
Most 4B lesions without proven malignant growth rate receive 3 month follow-up to exclude inflammatory nodule
Reclassified as 2 or 1 if shrinks or resolves

32. Lung-RADS: Suspicious Categories (4X)
Category 3 or 4 nodules with additional features or imaging findings that increase the suspicion of malignancy (spiculation, documented malignant growth rate, bulky central tumors with airway involvement, masses with adenopathy)

33. Lung-RADS: Suspicious Categories Management (?)
4A stable: reclassify as 2 and follow in 1 year
4A growing and 4B stable: Biopsy, PET CT staging and definitive management if positive
4B growing and 4X: PET CT staging. Histologic biopsy at time of surgery

34. Lung-RADS
Retrospective analysis of NLST patients with Lung-RADS suggested 10% category 3 and higher with 4% category 4
In practice, category 3 patients are almost all benign and the number of category 4 patients is more important.
Our category 4 rate is 3.6% for 2015 (Published rate 4%)

35. Lung-RADS: not usable outside of the screening setting
No time limits on follow-up recommendations
All exams with follow-up recommendation of routine rescreening are classified as negative, even those with findings which would require one, two or four year follow-up outside of a screening setting
It assumes a high risk patient population

36. Lung-RADS: Category 4S EDITORIAL COMMENT
Mortality reduction in the NLST was driven by lung cancer mortality
Findings like coronary artery calcium, thyroid nodules, emphysema, adrenal nodules, borderline renal cysts, mild interstitial disease…were not important.
A plea to radiologists: don’t mention these things. It’s ok. People will appreciate it

37. 10/12/2015
6/15/2010

38. New 8 mm mean diameter solid, non calcified nodule
Category 4B
Recommendation: 6 week follow up to exclude inflammatory lesion

39. 11/24/2015
10/12/2015

40. 12 mm spiculated solid nodule with significant growth in 6 weeks
Category 4X
PET CT staging.
Thoracoscopic left lower lobectomy and left hilar and mediastinal lymphadenectomy. Preliminary wedge resection and frozen not done due to incomplete fissure.
T1N0M0 squamous cell carcinoma. 9 weeks from detection to surgery

41. 12/4/2014
4/10/2014

42. New, 2 cm, solid, non calcified circumscribed nodule
Category 4X
Recommendation: Referral for definitive diagnosis and treatment
PET CT ordered by oncologist showed SUV 1.9, no hypermetabolic nodes
6 week follow-up CT ordered by oncologist

43. 01/19/2015
12/4/2014

44. 08/03/2015 (no comparison)

45. 4 cm, solid, non calcified spiculated nodule indeterminate stability
Category 4X
Recommendation: PET CT and referral for definitive diagnosis and treatment
PET CT showed hypermetabolic nodule and no other lesions
Uncomplicated right upper lobectomy. T2aN0M0 carcinoma

46. 2/09/2015
1/5/2015

47. 12 mm, solid, noncalcified, smoothly marginated nodule indeterminate stability stable on 6 week follow-up
Category 4A
Clinician elected biopsy to exclude slow growing tumor such as carcinoid
CT guided biopsy showed hamartoma
Could have been managed with long term follow up?

48. 10/12/2015
10/13/2014

49. 14 mm noncalcified polygonal solid nodule growing with doubling time 42 months
Category 4B
PT CT showed hypermetabolic nodule and no other lesions
Thoracoscopic wedge resection showed benign eosinophilic nodule
Could have been managed with CT guided biopsy?

50. Definitive Evaluation and Therapy of Suspicious Nodules
Traditionally, initial evaluation influenced by location of referral.
Patients referred to pulmonary tended to get bronchoscopy
Patients referred to surgery tended to get surgery without pre-operative histology
Patients managed by primary care tended to get CT guided biopsies

51. Multidisciplinary Evaluation (Nodule Board)
New imaging modalities (PET), invasive diagnostic modalities (Endoscopic ultrasound, computer guided bronchoscopy and CT fluoroscopy) and therapeutic modalities (SBRT) have complicated an already complicated process

52. Multidisciplinary Evaluation (Nodule Board)
Decisions regarding diagnosis, staging and treatment of suspected lung cancer are best made in a multidisciplinary setting, prior to any invasive testing or therapy

53. Multidisciplinary Evaluation (Nodule Board)
Radiologists need to get comfortable presenting patients at thoracic tumor boards
Radiologists can then communicate back to the referring primary care physician the next step (CT biopsy, pulmonary referral, surgery referral, rad oncology referral or oncology referral)