CT Low Dose Lung Cancer Screening. Part I. Journey to LDCT LCS Program

Transcription

1 CT Low Dose Lung Cancer Screening Part I Journey to LDCT LCS Program Paul Johnson, M.S., DABHP, DABR Cleveland Clinic September 26, 2015

2 Lung Caner is No. 1 In Cancer Related Death In The United States Lung cancer kills more people than breast cancer, colon cancer and prostate cancer combined 226,000 are newly diagnosed;; 160,000 die of lung cancer per year In comparison, 43,700 die of breast cancer per year Nearly 90% of lung cancers are related to smoking

3 Early Diagnosis of Lung Cancer Early diagnosis is the Only factor that improves survival From stage IA to IIIA, survival rate can drop 65% * Stanford University Healthcare Lung Cancer Screening Program.

4 Time Line of Lung Screening Events Denise R Aberle, MD, Screening Program Background and Initial Implementation AAPM 2015

5 PLCO Trial Determine the effect of screening chest radiography (CXR) on lung cancer specific mortality Randomized controlled trial of 154,901 subjects Annual P/A view CXR for 4 years or usual care Men and women aged 55 to 74;; no smoking requirement Never smokers received only 3 years of testing All subjects were followed for 13 years or until study conclusion *PLCO --- prostate, lung, colon, and ovarian

6 PLCO Trial No difference in mortality between screened and control Peter Mazzone, MD, Lung Cancer Screening

7 National Lung Screening Trial (NLST) 8/02 to 4/04: 33 US centers enrolled 53,454 people Low Dose CT: 26,722 and CXR: 26,732 More than 90% adherence to screening Rate of positive screening: LDCT: 24.2% vs. CXR: 6.9% Incidence of cancer: LDCT: 645/100,000;; CXR: 572/100,000 Deaths: LDCT: 356/100,000 vs. CXR: 443/100,000 A relative reduction of 20.0% in mortality from LDCT screening ( 95% CI 6.8 to 26.7;; p=0.004)

8 NLST Trial 20% reduction in mortality between screened and control group Peter Mazzone, MD, Lung Cancer Screening

9 CT vs. CXR For large calcified nodules, the CXR can detect equally well vs. CT

10 CT vs. CXR CXR may miss the large nodules due to overlay rib cages

11 CT vs. CXR CXR missed the non-calcified mass

12 CT detects diffuse Lung Nodules

13 CT vs. CXR: why CT scan is better? CT scan acquires tomographic image (no overlay ribs or organs) with various spatial resolution CT has better low contrast detectability (for no-calcified nodules) CT has dedicated recon kernel for lung nodules

14 NLST Guidelines for Screening Current or former smokers between years old Smoking at least 30 pack-years (for example, 2 packs a day for 15 years) Former smoker must have quit within the past 15 years

15 CMS Guidelines for Screening Asymptomatic current or former smokers between years old Smoking at least 30 pack-years Former smoker has quit smoking within the last 15 years

16 Pitfalls of CT Lung Screening Program Too many lung nodules (dilemma for radiologists) Radiation dose concerns Patient anxiety due to false positive results May give high risk patients (heavy smokers) a false assurance;; may feel protected by CT lung cancer screening, and continue smoking

17 From an International Trial Only missed 7% of cancers from 5mm to 9mm nodules

18 Based on the NLST Trial Only missed 7% of cancers from 4mm to 7mm nodules Peter Mazzone, MD, Lung Cancer Screening

19 Denise R Aberle, MD, Screening Program Background and Initial Implementation AAPM 2015

20 Difference between NLST and LungRADs Denise R Aberle, MD, Screening Program Background and Initial Implementation AAPM 2015

21 Smoking Cessation is the Key! Quit smoking at age 50 can reduce the lung cancer risk by almost 3x (300%) Peto. BMJ, 2000:321(7257)323-9

22 CT Low Dose Lung Cancer Screening Part II Scan protocols and dose tracking Frank Dong, PhD, DABR Cleveland Clinic September 26, 2015

23 CT Lung Cancer Screening Scan Parameters Scanner Gantry rotation period: 0.5s Recon Slice thickness: 2.5mm ( 1.0mm is recommended) No. of physical detector rows: 16 rows are preferred Low Radiation Dose CTDIvol <3mGy for a standard sized patient (5 7 and 154lbs) CTDIvol for smaller patients and for larger patients Use Automatic Exposure Control system if available Manual technique charts to adjust ma and/or kvp based on patient size

24 Single Breathhold To minimize respiratory motion, the CT lung screening scan should be completed within a single breathhold. ACR defined the length of a single breathhold 15s. Most CT scanners with 16 detector rows or more are capable of scanning through the entire lung (typical scan length is 30-35cm) within a single breathhold. Some 4 slice scanners may be marginally ok with 0.8s or faster gantry rotation speed, assuming the helical pitch ~1.5 is used. However, to scan through the lungs in a single breathhold and producing thin slices ( 1mm) will be a challenge for the 4-slice scanner.

25 ACR Designated Lung Screening Center Unit-specific Must have active ACR CT accreditation in chest module on designated unit(s) CT lung screening protocol form Attestation form on the ACR website Meet the requirement described in the application $400 per facility Center

26 ACR Designated Lung Screening Center Attestation form Recommended screening population Personnel qualifications Interpreting physicians Medical physicists and RT Follow up systems Structured reporting system (Lung-RADS) Smoking cessation CT Equipment QC Imaging protocol submitted Center

27 AAPM CT Lung Screening Protocols (Selected GE)

28 AAPM CT Lung Screening Protocols (Selected Siemens Sensation and Emotion)

29 AAPM CT Lung Screening Protocols (Selected Siemens Definition Family) 100kVp w/ a tin filter

30 AAPM CT Lung Screening Protocols (Selected Philips ict)

31 AAPM CT Lung Screening Protocols (Selected Toshiba)

32 CCF Lung Cancer Screening Program We have 4 designated lung cancer screening centers: the main campus, Hillcrest, Fairview and Weston (FL) The program is led by a pulmonologist Dr. Peter Mazzone 5 chest radiologists are trained to read all CT lung cancer screening studies On average, about 40 CT screening cases per month first half of Expecting the volume increases as the program expands to the regional sites. Consultation are done only at the main campus and the Weston facility

33 CCF Education Program Education is the key for the program to become standard of care and to ensure that patient expectations are realistic. Internal communication, grand rounds, lung cancer conference, satellite visits. A patient information brochure is provided at the time of order placement and at the time of the test.

34 Patient Information Brochure

35 CCF CT Protocols and Dose Tracking Low dose CT lung screening protocols are based off AAPM recommended protocols Technique parameters were adjusted due to lack of iterative reconstruction Some scanners do not have the iterative recon option Some of chest radiologists are not in favor of using IR Dose information from CT lung screening is sent to the ACR Dose Index Registry (ACR DIR) CTDIvol outliers from the lung screening CTs are tracked for quality improvement

36 CTDIvol vs. Patient Weight One site had a CT screening protocol w/ high techniques and AEC off. CTDIvol >3mGy ( 3mGy is the red horizontal line) even for small size patients (the data to the left of the green vertical line) 154lbs 3mGy

37 CTDIvol vs. Patient Weight Removed the data points from the site, CTDIvol followed patient weight in a more linear fashion. 154lbs 3mGy

38 Challenges to the Program Standardized interpretation/management Reducing false positive rates Managing the incidental findings Documenting satisfaction of CMS requirements Effectively integrating smoking cessation into the program Would negative screening results discourage smoking cessation? How to effectively target the patient group with the smoking cessation program? Maintaining costs of the program

39