Percutaneous Treatment of Thoracic Malignancy

1. Percutaneous Treatment of Thoracic Malignancy William Moore, M.D. Associate Professor of Radiology Stony Brook University Medical Center Union University 10/19/2012

2. Objectives: • Epidemiology of Lung Cancer. • Technique of Percutaneous Ablation. • Radiofrequency Biology of Cell Death. • Cryobiology of Cell Death. • Imaging Follow–up. • Preliminary Data.

3. Epidemiology 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

6. So how do we find a lung cancer?

7. So how do we find a lung cancer? • Chest x-ray • CT

15. So how do we find a lung cancer? • Chest x-ray • CT • Bronchoscopy • Findings metastatic disease elsewhere

16. Standard 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)

17. Limited 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.

18. External 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;36:607-613. ** Chest: 2002;121;1155-1158

19. Surgical Resection No Rx XRT Chest: 2002;121;1155-1158 Chest: 2007; 123; 193-200

20. So what else could we do?

21. Local therapy has been tried • What is the goal? • Cure • What could we use? • Microwave • Laser • Radiofrequency • Freezing • Heating • IRE

22. General Ablation Technique: • CT guidance is used for ALL lung applications • We use general Anesthesia for all procedures. • Total anesthesia time is about 1-1.5 hours.

23. Start RFA

24. RFA technique: RF Generator RFA Electrode Patient return/grounding pads

25. RFA technique:RITA/Angiodynamics • Starburst Probes • We 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 system • Saline goes into the patient and diffuses among the lung propagating the RF signal (0.1cc/min)

26. Cool-Tip Electrode

27. RFA technique:Valley-labs • The single probe: • This is for smaller lesions. • There is a 3 cm exposed tip.

28. Cluster tip probe. • Three separate tips are on this single shaft probe. This has a 3 cm tip exposure. With a 5-6 cm spherical kill zone • 12-16 minute total burn

29. RFA Mechanisms of Cell Destruction

30. Tumor 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.

31. Tumor Biology with RFA: • At 105-115 °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.

32. Cryoablation • 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.

33. Isotherm forms a 2.4 mm Right Angle CryoProbe

34. PCT Technique: • Depends on the size of the lesion. • Small lesions (1-2 cm) • Single Needle; place the needle in the center of the lesion.

35. PCT Technique: • Larger Lesions (>2.0-3.5 cm) • Cluster technique • Several needles clustered around the lesion.

36. Ablation Protocol • We perform a freeze-thaw-freeze cycle on all tumors. • 10 minute freeze • (-140°C) • 8 minute thaw • (Never go above 0° C) • 10 minute freeze • 3 minute thaw to remove the needle from the ice block. Total Ablation time 28 minutes

37. 1996Argon Based Joule-Thompson Cryoprobes

38. Ice Ball Formation Different gases have different Joule–Thomson (Kelvin) coefficient Helium is warmer at 1 atmosphere while most other gases aka Argon get colder.

39. Cryobiology Mechanisms of Cell Destruction

40. Freezing Damage Mechanisms Freezing tissue damages cells in two ways: 1. Direct damage (to the cells) at the time of cryoablation • Slow cooling injury • Fast cooling injury 2. Indirect damage (to the tissue) following cryoablation • Ischemia • Apoptosis

41. Direct Damage When cells are frozen quickly: • Water is trapped inside the cell because of how fast the temperature decrease • This results in Intracellular Ice Formation (IIF) • The cytoplasm becomes supercooled • This damages the cell membrane. • Holding the freeze causes recrystallization increasing cell damage.

42. Direct Damage When cells are frozen slowly: • Ice forms in the extracellular matrix • The cell dehydrate but now has more concentrated cytoplasm • Upon thawing cell rehydrates and expands beyond the membrane resulting in lysis

43. Indirect Damage • Two theories • Blood vessel engorgement • Ice formation causes vessel wall engorgement and distention resulting in stasis. • Damage to the endothelial cells • Much like direct causes but this results in decreased blood flow to the tumor. • Final result necrosis

44. Complications:for RFA and PCT

45. Immediate complications: • Pneumothorax • Small: 30% of our cases Up to 50% in literature • Large: 20%; all required chest tubes • Three required prolonged hospitalization. • Pulmonary Hemorrhage: • Minor degrees in almost all cases. • Hemoptysis: • Moderate (200 cc) in 1 of cases.

46. Follow-up? We follow patient with CT with contrast And Positron Emission Tomography (PET) imaging.

47. Contrast CT • CT 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 them • More iodine means more attenuation of x-ray beams.

49. PET • 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 10-13 mCu and image 1 hour later.

50. PET • 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.