SPNs and the Early Detection of Lung CancerGeorge Erbacher D.O., FAOCR
Chair imaging/interventional radiology OSUMC
Radiology residency program director
DEFINITION OF SOLITARY PULMONARY NODULE (SPN)Single round water density mass < 3 cmCompletely surrounded by lung parenchymaIncidental finding 0.2% CXRs, 1% CT
MIMICS OF SPN
Chest wall lesionHealing rib fracture AVNAbscessPneumoniaImmune-RA/Wegeners granulomatosis etc.
MIMICS OF SPNHematomaLung infarct/atelecatasisPleural plaqueBronchial atresia/SequestrationInhaled FBMOST COMMON: BENIGN GRANULOMA/HAMARTOMA
PATIENT FEATURES INCREASING RISK OF MALIGNANCYSMOKING ESPECIALLY >20 PK/YEAROlder agePersonal history of malignancyFirst degree relative with lung cancerAsbestos/uranium/radon exposureOther workplace exposure- some aromatic hydrocarbons, coal mines etc.
IMAGING FEATURES BENIGN VS. MALIGNANTSmaller less risk of malignancyWell defined borders tend to be benignIf a cavity thin walls-favor benignPopcorn like calcification benign characteristic of hamartomaDensity (HU) < 15-20 benignVery fast and very slow growing lesions are likely benign-PREVIOUS COMPARISON IMAGES ARE CRITICAL
Epidemiology Lung Cancer in the World
Most frequently diagnosed cancer (1.04M in 1990)Leading cause of cancer mortality 921K deathsMost common cancer in males and #1 cause of cancer death
Incidence Lung Cancer in U.S.171,600 cases diagnosed in 1999 (94K M; 77.6K F)Leading cause of cancer death M & F (158.9K)Kentucky highest mortality rate 67.9/100K (37% above avg.)Utah lowest mortality rate21.6/100K (56.4% below avg.)
U.S. Lung Cancer1Dupuy, DE. Percutaneous radiofrequency ablation of pulmonary malignancies: combined treatment with brachytherapy. Am J Roentgenol. 2003;181(3):711-5.Lung cancer is the leading cause of cancer mortality in the U.S. among both men and women surpassing totals from breast, colon, and ovarian cancers combined. 
Survival5 years 14%
50% survive if diagnosed in early stage (small size IA 85 100% survival
Only 15% diagnosed in early stage
Tobacco SmokeCigarette smoking is causally related to lung cancerthe magnitude of the effect far outweighs all other factors.
Is leading cause of avoidable mortality in US, w/ about 434K preventable deaths per yearCost to US economy $200 billion/year
US surgeon general
CXR Screening RevisitedAnalysis of the 4 RCT from 20 years ago (Mayo, Czech, Sloan-Kettering, Johns-Hopkins)
Czech & Mayo studies found increase in mortality in screened vs. controls (6% increase in Mayo) however 29% MORE lung cancer in screening vs. controls
CXR Screening RevisitedScreened had 34% living @ 5yrs vs. 15% control (Sloan-Kettering, Johns-Hopkins similar results)
Analysis of the randomized trials strongly suggests CXR screening is superior to no screening whatsoever
Low Dose CT (LD CT)Screening vs. CXRRationale:LD CT greatly increases detection of small non-calcified nodules and of lung cancer at an earlier/more curable stageLD CT showed non-calcified nodules 3x more commonlyLD CT showed malig. tumors 4x more commonlyLD CT showed stage 1 tumors 6x more commonly
LD CT Indication (ELCAP)> 60 y.o.a.
> 10 pk/y smoker & no previous cancer
Medically fit to undergo thoracic surgery
Baseline LD CT, then annuals
ELCAP Technique Helical CT140 kVp, 40 mA2:1 Pitch, 10 mm slice thicknessScan entire lung in 1 breath hold @ end inspiration after hyperventilationReconstruct images with bone algorithm in overlapping 5 mm incrementsOnly lung windows (W1500, L-650) reviewed
ELCAP Scoring1-6 non-calcified nodules = positive
If no non-calcified nodules = negative
> 6 non-calcified nodules, diffuse bronchiectasis, ground glass opacities or combinations = diffuse disease
ELCAP Nodule DescriptionSize (L & W/2)Location (lobe & distance from pleura) peripheral if w/in 2 cm costal marginBenign calcificationsShape (round, non-round)Edge (smooth, non-smooth)
ELCAP Benign NoduleBenign calcifications
< 20 mm size
Guideline for Diagnostic Intervention ELCAPNon-benign nodule on LD CT goes to diagnostic CT w/ high resolution imaging of abnormalities. If not benign per above criteria:< 5mm : F/U high res CT 3 mo, 6 mo, 12 mo, 24 mo; no growth over 3 yrs=benign6-10 mm : bx, if not possible F/U per above> 11mm : bx
Fleishner Recommendations do NOT apply to patients:
Fleishner Nodule CT Reassessment RecommendationsNONCONTRASTTHIN COLLIMATIONLIMITED COVERAGE-JUST REGION OF INTERESTLOW DOSE
Nodule Enhancement and metabolismCancer/Infection/inflammation- CT neovascularity- malignant nodules enhance > 20 Hounsfield Units (HU), benign < 15 HU
Cancer/Infection/inflammation- increased glucose turnover- PET- SUVmax < 2.5 benignPET/CT HAS SENSITIVITY AND SPECIFICITY CLOSE TO 90% FOR NODULES 10 MM OR GREATER DIAMETER
PET/CT vs. Helical dynamic CT for SPNPET/CT MORE SENSITIVE (96% vs. 81%) and MORE ACCURATE (93% vs. 85%) than helical dynamic CT
Caveats for PET/CT:NO STANDARIZATION FROM ONE MACHINE TO ANOTHER AND POOR STANDARDIZATION OFTEN BETWEEN EXAMINATIONS ON THE SAME MACHINE.EXPERIENCE OF TECHNOLOGISTS-RADIOLOGISTS VARIES WIDELY
Benign? NM in Lung Cancer
Role of PET in Lung Cancer
Improves staging by ruling out mediastinal/distant diseaseUseful in evaluating response to therapyUseful in early detection recurrent disease
Rad Clinics N.A. May 2000 p. 523
False Positive and Caveats PET/CTActive necrotizing granulomas and some chronic inflammatory conditions are +ANY PROCESS THAT HAS INCREASED UPTAKE OF GLUCOSE IS PET POSITIVE
What to do with Indeterminant CT W/U of SPNSerial radiographic F/U?
CT alone to decide to surgerize or not?
Surgery for pts w/ + or indeterminant CT?
Cost EffectivenessRadiographic F/U cost effective when probability of malignancy is low ( .90Over greatest range of probability .14 - .71 CT and PET/CT cost effectiveRad Clinics N.A. May 2000 p. 521-522
PRINCIPLES OF IMAGING IN ONCOLOGYImaging justified only if results will change therapy with patient benefitWhere there is an issue get tissue-biopsy when imaging is inconclusive (imaging guided?)Positive studies are more valuable/reliable than negative studiesThe diagnostic plan should progress logically from least to most invasive studiesAccurate assessment of initial disease extent is vital to selecting and sequencing appropriate treatment
Staging lung cancerStage 1A-T1N0MO= tumor < 3cm with no positive nodes and no metastasisStage 1B-T2N0M0- tumor > 3cm, no nodes, no metastasis
RFA in Pulmonary Applications
Lung25% of patients are candidates for lung resection. 
RT and chemotherapy together have a combined 5 year survival rate of 5%. 
RF ablation can potentially provide direct cytoreduction, which could make RT and chemotherapy more effective. 1Dupuy, DE. Percutaneous radiofrequency ablation of pulmonary malignancies: combined treatment with brachytherapy. Am J Roentgenol. 2003;181(3):711-5.
Lung CancerAssessment of malignancy has required invasive diagnostic methodsNeedle biopsy (10% sampling error; 15% pneumothorax)Bronchoscopy (low sensitivity; occ. pneumothoraxMediastinoscopy (surgical procedure; limited to anterior mediastinum)Thoracotomy (open surgery; 1-3% mortality)FDG-PET expensive and not widely available
Lung CancerRadiofrequency ablation of lung tumors may be a promising option for nonsurgical candidates given the suboptimal outcomes with current treatment options. 
The overall 5-year survival rate for all stages combined is only 15%. 
1Dupuy, DE. Percutaneous radiofrequency ablation of pulmonary malignancies: combined treatment with brachytherapy. Am J Roentgenol. 2003;181(3):711-5.
Radiofrequency AblationNSC Lung Cancer3 cm RFA3 mo S/P RFA/XRT18 mo S/P RFA/XRT
KEYSExcellent H&PFind ComparisonsSend the above to your radiologist then call and discuss the case-have the radiologist lay out the work up as local resources dictate what will be doneIF PATIENT CANDIDATE FOR TREATMENT TISSUE DIAGNOSIS IS NEEDED
We at Diagnostic Imaging Associates are happy to helpFOR TULSA REFERRAL AREA CALL 918 599 5050/5094 TO TALK TO RADIOLOGIST
FOR OUTSIDE TULSA REFERRAL AREA CALL CHRISTA -918 599 5031 and ask for radiologist at site nearest you