Rodney C Richie MD FACP FCCP DBIM Texas Life and EMSI

Transcription

1 Rodney C Richie MD FACP FCCP DBIM Texas Life and EMSI

2 Pulmonary Nodules Well-circumscribed, radiographic opacities measuring 3 cm in diameter Surrounded by aerated lung Not associated with atelectesis or pleural fluid Solitary or Multiple Lung Mass 3 cm (malignant until proven otherwise) Pulmonary Nodules

3 Multiple Nodules Concern for malignancy increases with Presence of a dominant nodule or mass Variation in size of the nodules Distribution in the lower lung zones, consistent with hematogenous metastatic growth Any past history of malignancy Lack of presence of nodules on old CXR or CT imaging Differential Diagnosis of SPN (Solitary Pulmonary Nodule) Benign Granulomas Fibrotic nodules Inflammatory nodules (infection) Harmatomas Rounded atelectesis Hemangiomas AVM Healed pulmonary infarcts Malignant Lung cancer (NSCLC and SCLC) Metastatic disease Carcinoid tumors

4 5-year Survival of Lung Cancer by Clinical versus Pathologic Staging Stage Clinical Staging Pathological Staging IA IB IIA IIB IIIA IIIB 7 9 IV 2 13 J Thorac Oncol 2007; 8: Radiographic Imaging of SPNs Plain-film CXR: > 3-5 mm growth is required to detect change > 2 years of unchanged size is no longer accepted as adequate criteria for lesion being benign CT Lung: > mm growth required to detect change CT Lung is the only accepted way to follow SPNs PET scans: Requires nodule size > 8mm and will not distinguish inflammatory from malignant nodules

5 CT Imaging of SPNs Margins Spiculated = high incidence for malignancy Scalloped = intermediate incidence for malignancy Smooth = low incidence for malignancy Calcification Usually seen in benign nodules Exception: Eccentric calcification Spiculated-margined SPN This lesion demonstrates the corona radiata sign which is highly associated with malignancy

6 Benign Patterns of Calcification CT Imaging of SPNs Rate of growth is key The volume-doubling time for malignant bronchogenic tumors is rarely less than a month or more than a year For spherical lesions, a 30% increase in diameter represents a doubling of volume With CT resolution of nodules being 0.3 mm, lack of growth of an SPN by CT > 2 years may be accepted as evidence of benignity. - Ost et al. N Engl J Med 2003; 348: True, but no longer the way we evaluate SPNs!

7 New Approach to SPNs New Approach to SPNs

8 CT Imaging of SPNs CT densitometry Involves measurement of attenuation values expressed in Hounsfield units In one large multicenter trial only 1 nodule among 66 with Hounsfield unit > 264 ultimately proved to be malignant. - Zerhouni et al. Radiology 1986; 160: Use of contrast enhancement An increase in attenuation of > 20 Hounsfield units may suggest a nodule to be malignant - Zhang and Kono. Radiology 1997; 205: CT Imaging of SPNs Ground-glass appearance Favors malignancy Requires > 2-years of CT follow-up Bronchoalveolar carcinoma* may be eventually found *New terminology = AIS Adenocarcinoma in situ

9 Ground-glass SPNs Ground-glass infiltrate on left has a 1:5 chance of malignancy. The ground-glass + solid component lesion on the right has a 2:3 likelihood of malignancy. Any ground-glass SPN may ultimately prove to be AIS and serial CT > 2 years may be needed. High versus Low Risk Patients Older age Smoker COPD Prior malignancy

10 Radiology of Benign v. Malignant SPN Radiologic Feature Benign Malignant Size < 5 mm > 10 mm Border Smooth Irregular or spiculated Density Dense, solid Varigated, groundglass Calcification Doubling Time Central, concentric, popcorn, or homogeneous Less than 1 month, greater than 1 year Non-calcified or eccentric calcification One month to one year SPN Calculators Calculator.aspx I entered the following into each calculator 70 year old Never-smoker Size: 1 cm Location: Upper/middle zone of lung Contour: Smooth Likelihood of malignancy First calculator = 12% Second calculator = 11.6%

11 SPN: Size really matters < 5 mm 0-1 % 5-10 mm 6-28% > 20 m % Diameter Risk of Malignancy Screening for Early Lung Cancer 5-year survival for lung cancer in the US is 15.6% vs. > 90% for Breast, Colon, and Prostate Cancers New recommendations just promulgated by ATS, ACS, ACCP and others Annual low-dose CT imaging indicated for: Persons Current smokers or past smokers with > 30- pack/yr hx

12 Thank You Rodney C Richie MD FACP FCCP DBIM Texas Life and EMSI