Presentation on theme: "Percutaneous Treatment of Thoracic Malignancy"— Presentation transcript:
1Percutaneous Treatment of Thoracic Malignancy William Moore, M.D.Associate Professor of RadiologyStony Brook University Medical CenterUnion University10/19/2012
2Objectives: Epidemiology of Lung Cancer. Technique of Percutaneous Ablation.Radiofrequency Biology of Cell Death.Cryobiology of Cell Death.Imaging Follow–up.Preliminary Data.
3Epidemiology of lung cancer. Lung cancer is the leading cause of cancer related death for both men and women in the United States.In 2009:estimated 219,440 cases of lung cancer diagnosed in the US and 1.3 million cases worldwide.159,000 deaths from lung cancer were estimated in the United States in 2009
15So how do we find a lung cancer? Chest x-rayCTBronchoscopyFindings metastatic disease elsewhere
16Standard Therapy for Lung Cancer: Lobectomy is the standard therapy for stage I non-small cell lung cancer (NSCLC).5-year survivals as great as 80-90% and local recurrence rates of 5%.Unfortunately, only 30% of cases are resectable at the time of diagnosis.Secondary other medical conditions (PFT)
17Limited Resection:For the moderately compromised patient, sublobar resection is an option.The main concern with sublobar resection is the increased local recurrence relative to lobectomy.For patients who are unable to tolerate pulmonary resection, external beam radiation (XRT) has traditionally been used.
18External Beam Radiation: Treatment results are inferior to those of resection.In a study of Stage 1 Lung cancers who received XRT of at least 60 Gy.3 year survival 19%.*5-year survivals 12%.*Median survival is estimated at 19.9 months.***Kupelian PA, Komaki R, Allen P. Int J Radiat Oncol Biol Phys. 1996;36:** Chest: 2002;121;
25RFA technique: RITA/Angiodynamics Starburst ProbesWe use the Starburst Talon 4 cm probe.This has a flexible handle which is 20 cm long. Perfect for CT applications.Sterile saline infusion pump systemSaline goes into the patient and diffuses among the lung propagating the RF signal (0.1cc/min)
30Tumor Biology with RFA: At 45 °C cellular swelling begins.The minimal acceptable tissue temperature for cell death is 60 ° C.Cellular proteins are denatured enzymes are deactivated and cellular death results.
31Tumor Biology with RFA: At °C charring of tissue can occur.Cavitation or gas formation also occur at this temperature.The impedance (tissue resistance to energy flow) increases dramatically.This is a problem in the lung because of possible air emboli to the brain.Stroke is a known risk with RFA.
32Cryoablation This is a freezing procedure. Just like the RFA we place a needle into the lesion and rather then heat it up we freeze it.
33Isotherm forms a 2.4 mm Right Angle CryoProbe DIAMETER(MM)LENGTH0oC3756-20oC2444-40oC1636
34PCT Technique: Depends on the size of the lesion. Small lesions (1-2 cm)Single Needle; place the needle in the center of the lesion.
35PCT Technique: Larger Lesions (>2.0-3.5 cm) Cluster technique Several needles clustered around the lesion.
36Ablation Protocol We perform a freeze-thaw-freeze cycle on all tumors. 10 minute freeze(-140°C)8 minute thaw(Never go above 0° C)3 minute thaw to remove the needle from the ice block.Total Ablation time 28 minutes
38Ice Ball FormationDifferent gases have different Joule–Thomson (Kelvin) coefficientHelium is warmer at 1 atmosphere while most othergases aka Argon get colder.
39Mechanisms of Cell Destruction CryobiologyMechanisms of Cell Destruction
40Freezing Damage Mechanisms Freezing tissue damages cells in two ways:1. Direct damage (to the cells) at the time of cryoablationSlow cooling injuryFast cooling injury2. Indirect damage (to the tissue) following cryoablationIschemiaApoptosis
41Direct Damage When cells are frozen quickly: Water is trapped inside the cell because of how fast the temperature decreaseThis results in Intracellular Ice Formation (IIF)The cytoplasm becomes supercooledThis damages the cell membrane.Holding the freeze causes recrystallization increasing cell damage.
42Direct Damage When cells are frozen slowly: Ice forms in the extracellular matrixThe cell dehydrate but now has more concentrated cytoplasmUpon thawing cell rehydrates and expands beyond the membrane resulting in lysis
43Indirect Damage Two theories Final result necrosis Blood vessel engorgementIce formation causes vessel wall engorgement and distention resulting in stasis.Damage to the endothelial cellsMuch like direct causes but this results in decreased blood flow to the tumor.Final result necrosis
45Immediate complications: PneumothoraxSmall: 30% of our cases Up to 50% in literatureLarge: 20%; all required chest tubesThree required prolonged hospitalization.Pulmonary Hemorrhage:Minor degrees in almost all cases.Hemoptysis:Moderate (200 cc) in 1 of cases.
46Follow-up? We follow patient with CT with contrast And Positron Emission Tomography (PET) imaging.
47Contrast CTCT works by stopping the beam of radiation as it passes through a structure.The radiation is collected by the detector and then depending on the density of the structure it will give a specific level of gray.When we add contrast (aka Iodine) structures that are vascular have more iodine in themMore iodine means more attenuation of x-ray beams.
49PET Works by given a high energy particle; 1.22 MeV particle to the patient which is coupled to FDG-a glucose analog.This particle is radioactive and breaks down with time. T1/2 3 hours.We inject a standard amount mCu and image 1 hour later.
50PET The particle decays by annihilation. This means that the particle breaks in half and goes in opposite directions.511 keV at 180 degrees to each other.
51PETThe detector will only image the particles that hit the detectors at the same time at 180 degrees.The glucose is held in the metabolically active cells because of the fluoride which is added to the glucose.
57Conclusions:RFA and Cryoablation are safe alternatives to standard non-surgical therapy for lung cancer and pulmonary metastatic disease.Long term data in the lung is starting to surface for RFA but not PCT.Carefully, performed clinical trials are necessary to determine the exact role of these interventions in patients with lung cancer.
58References:Wang H, Littrup P, Duan Y, et al. Thoracic Masses Treated with Percutaneous Cryotherapy: Initial Experience with More than 200 Procedures. Radiology 2005; 235:289–298Swensen SJ, Viggiano RW, Midthun DE, et al Lung nodule enhancement at CT: multicenter study. Radiology 2000; 214:73–80Shankar LK, Hoffman JM, Bacharach S, etal. Consensus recommendations for the use of 18F-FDG PET as an indicator of therapeutic response in patients in National Cancer Institute Trials. J Nucl Med. 2006;47:Hoffman NE, Bischof JC. The Cryobiology of Cryosurgical Injury. Urology 2002 (Suppl 2A):de Baere T, Palussiere J, Auperin A, et al Midterm local efficacy and survival after radiofrequency ablation of lung tumors with minimum follow-up of 1 year: prospective evaluation. Radiology Aug;240(2):Zemlyak A, Moore WH, and Bilfinger TV. Comparison of survival after sublobar resections and ablative therapies for stage I non-small cell lung cancer. Journal of the American College of Surgeons 211(1):68-72, 2010