Spotlight Case

1. Spotlight Case The Lung Nodule That Refused To Grow

2. Source and Credits • This presentation is based on the December 2012AHRQ WebM&M Spotlight Case • See the full article at http://webmm.ahrq.gov • CME credit is available • Commentary by: Alex A. Balekian, MD, MSHS, Keck School of Medicine, and Michael K. Gould, MD, MS, Kaiser Permanente Southern California • Editor, AHRQ WebM&M: Robert Wachter, MD • Spotlight Editor: Bradley A. Sharpe, MD • Managing Editor: Erin Hartman, MS

3. Objectives At the conclusion of this educational activity, participants should be able to: • Define a solitary pulmonary nodule • Identify the different initial first steps of management • Identify factors associated with malignant or benign disease • Understand when patients no longer need surveillance for benign disease

4. Case: Lung Nodule After moving to a new city, a 67-year-old man presented to a primary care physician for an initial visit to establish care. In discussing his past medical history, the patient described having a “spot” on his lungs that doctors had been following since 2004.

5. Definition: Solitary Pulmonary Nodule • The solitary pulmonary nodule (SPN) can be defined as a single, well-circumscribed radiographic density: • Measuring less than 3 cm • Surrounded by aerated lung • Without any evidence of atelectasis, hilar enlargement, or pleural effusion See Notes for reference.

6. Diagnosing Solitary Pulmonary Nodule • Differential diagnosis includes malignant, infectious, inflammatory, and miscellaneous benign etiologies • Depending upon study population, between 15% to 75% of these nodules prove to be malignant • Increasingly common for SPNs to be discovered incidentally on chest CT scans performed for other reasons See Notes for references.

7. Characteristics of CT Findings • Associated with a benign etiology • Smaller size, fat density, or a central, diffuse, or popcorn pattern of calcification • Associated with malignancy • Larger size, upper lobe location, irregular margins or spiculation, thick-walled cavitation, and hilar or mediastinal lymphadenopathy

8. Solid nodule with eccentric calcification. Followed over 2 years. Dx: Stable nodule.

9. Solid nodule with lobulated border. Followed over 2 years. Dx: Stable nodule.

10. Solid nodule with irregular border. Biopsied immediately. Dx: lung cancer.

11. Risk Factors for Malignancy • Patient-specific risk factors for malignancy with SPN are: • Older age • Current or former smoking status • Prior history of extrathoracic malignancy • Asbestos exposure

12. Prediction Models for Malignancy • Three prediction models are available • Memorial Sloan-Kettering • Mayo Clinic • Veterans Affairs • These models combine patient-level and radiographic characteristics to estimate the probability of malignancy of SPN See Notes for references.

13. Management Strategies • Based on the clinical probability for malignancy (low, intermediate, high), clinicians can use these models to choose an appropriate management strategy • Monitoring with serial CT scans • Performing functional imaging with positron emission tomography (PET) scanning • Proceeding directly to biopsy or surgical resection See Notes for references.

14. Errors in Management • The most common, avoidable error in management is neglecting to review prior imaging studies • Obtaining prior chest radiographs or CT scans for comparison can be essential to management • For example, if a solid nodule was present for 2 or more years and had not changed, this finding is very strong evidence of a benign etiology, and no additional follow-up would be required See Notes for reference.

15. Errors in Management (2) • Next most common error is choosing a strategy of “wait and watch” but neglecting to “watch” • To date, robust electronic reminder systems for nodule evaluation have not been widely adopted • These kinds of systems-level solutions need to be developed and tested See Notes for reference.

16. Case: Lung Nodule (2) Upon further history, the patient stated that while undergoing a hernia surgery in 2004, a nodule was seen on a routine chest radiograph. It was followed up at the time with a computed tomography (CT) scan and a positron emission tomography (PET) scan. Based on these results, the nodule was felt to be benign and not an active malignancy or infection. The patient had no symptoms from the nodule.

17. Management After Chest CT • After chest CT has been performed, there are four possible alternatives for the next step in nodule evaluation: • PET scan • Non-surgical biopsy • Surgical diagnosis • Surveillance

18. PET Scanning • PET scans use 18-fluorodeoxyglucose (FDG) to measure metabolic activity of a nodule • Although malignant cells will “light up” on a PET scan, infections and other types of inflammation (e.g., granulomatous) will also yield positive results, thereby compromising the test’s specificity

19. PET Scanning (2) • The American College of Chest Physicians (ACCP) recommends PET for characterization of solid nodules measuring >8 mm with a low to moderate probability for malignancy • If PET shows increased uptake, it would prompt either biopsy or timely resection • If PET shows no increased uptake, then watchful waiting with periodic surveillance is usually the preferred course See Notes for reference.

20. Non-surgical Biopsy • Non-surgical biopsy is less invasive than surgical diagnosis • Can be performed via transthoracic needle biopsy (TTNB) for peripheral lesions or bronchoscopy for central lesions • Bronchoscopic procedures can simultaneously stage the mediastinal or hilar lymph nodes in the case of lung cancer See Notes for reference.

21. Non-surgical Biopsy (2) • For most nodules, CT-guided TTNB will have a higher yield than the newer guided bronchoscopic techniques • But transthoracic biopsy carries a higher risk of pneumothorax requiring chest tube placement (~7%) See Notes for reference.

22. Surgical Diagnosis • Surgical diagnosis is often preferred for nodules that are very likely to be cancerous • The surgery is usually performed via a video-assisted thorascopic surgery (VATS) • Procedure is generally well-tolerated and the risk of a fatal complication from VATS wedge resection is low (<0.5%)

23. In This Case • The nodule was “felt to be benign” based on the CT and PET results, suggesting that there was little or no FDG uptake on the PET scan • However, negative PET scan does not necessarily exclude possibility of malignancy and additional follow-up is required • Providers can follow the Fleischner Society recommendations for follow-up (see next slide)

24. Guidelines for Follow-up

25. Case: Lung Nodule (3) The patient had a 6-month follow-up CT scan in 2004 confirming the nodule’s presence and that it had not grown or changed. Subsequently, the patient had chest CT scans with and without contrast every 6−12 months for 8 years that further showed no change in size or character of the nodule. In total, he had more than 20 CT scans of the chest. The primary care doctor wondered if all of the CT scans were necessary and how the nodule should have been managed.

26. Case Conclusion • Eight years of follow-up was excessive and did not follow expert guidelines • If the nodule was calcified on the initial CT scan, then no additional follow-up would have been required • If the nodule was solid but non-calcified, then 2 years of stability would have been enough to exclude malignancy

27. Take-Home Points • Small pulmonary nodules (≤8 mm) are usually managed by CT surveillance • For small, solid nodules, the frequency and duration of surveillance are guided by recommendations from the Fleischner Society • For sub-solid nodules, the optimal frequency and duration of follow-up are uncertain; there is an emerging consensus favoring extended duration follow-up in the range of 3 to 5 years

28. Take-Home Points (2) • A systematic approach to evaluating larger (>8 mm), solid nodules includes the following steps: • Review old imaging studies • Estimate clinical probability of malignancy by considering both patient risk factors and nodule characteristics, or by using a validated prediction model • Use functional imaging (typically with FDG-PET) to further characterize nodules when clinical probability is low to moderate

29. Take-Home Points (3) • Provide information about likelihood of cancer, risks of procedures, and potential benefits and harms associated with each of the alternatives for evaluation • Elicit patient preferences for alternatives and outcomes and help patient make the best choice between CT surveillance, non-surgical biopsy, and surgical diagnosis