IMAGE-GUIDED ABLATION OF LUNG NEOPLASMS

Servet Tatli MDAssociate Professor of Radiology

Harvard Medical School

Department of RadiologyBrigham and Women’s Hospital

Objectives

• Review of image-guided tumor ablation technique to treat lung neoplasms

• Discuss technical issues that may arise during image-guided ablation of lung neoplasms with some illustrated examples

• Nothing to disclose

NSCLC• 2nd most common cancer in both men and women

• By far the leading cause of cancer related deaths in both gender

• Surgical resection remains the mainstay for early-stage (stage I/II) NSCLC(Rajdev L, Surg Oncol 2002)

– only 30% patients with disease confined to lung (stage I/II)• only 1/3 of these are surgical candidates

Lung Metastases

• The second most common organ for metastases

• ~20% patients with primary site removed are found to have metastases limited to the lungs– colorectal, osteosarcoma, RCC, testis, breast, melanoma

(Pastorino U, J Thor Cardiovasc Surg 1997)

• Resection of pulmonary metastases may result in improved disease-free survival (Saito Y, J Thor Cardiovasc Surg 2002)

– not candidates for surgical resection• low pulmonary reserve, co-morbid conditions, diseases in both lungs

Prognosis

• High number of poor surgical candidates

• Unsatisfactory response to conventional treatment methods

necessitate alternative treatment methods

Alternative

Image-guided thermal ablation techniques such as RF ablation

may be alternative treatment option

for these patients’ groups

Patient Selection• Stage I/II NSCLC: non surgical candidates

• Solitary or limited number lung metastasis without extrapulmonary disease

• Stage III/IV NSCLC and pulmonary metastasis – local tumor control– symptom palliation (chest pain, cough, dyspnea,

hemoptysis)

Tumor Selection• Size

– < 3 cm (ideal)– up to 5 cm

• Number– <3-5– exceptions (adenoid cystic carcinoma of salivary glands)

• Location– pleural-based– intraparenchymal (surrounded by lung parenchyma)

• >1 cm from bronchus, hilum, mediastinum (heart, trachea)

Patient Evaluation

• Evaluation by thoracic oncologist / surgeon• Consultation with interventional radiologist

– rationale: cure, local tumor control, symptom palliation– feasibility: size, location, access route– risk/benefit– cardiopulmonary status

• cardiology evaluation

• pulmonary function test

– medications (anticoagulants) – concurrent pulmonary infection

Patient Evaluation

• Percutaneous biopsy for pathological diagnosis– may not need in every case

• prior path diagnosis, new mass, FDG avidity > 4 SUV

• Baseline imaging: CECT, MRI, PET/CT– no more than 4 weeks before than RF ablation

• Anesthesia consult

• Coagulation workup: PT, PTT, INR, platelet, hct

Preparation

• Discontinue anticoagulants

• Overnight fasting

• Prophylactic antibiotics– broad-spectrum: Ancef 1-2mg, IV

• Pacemaker malfunction; needs temporary deactivation (RF ablation)

Guidance• US: lack of acoustic penetration due to bones and lungs

– may be used for pleural based or chest wall tumors

• MRI: limited availability– poor visualization of ablation applicator– require MR compatible equipment

• CT: imaging modality of choice– excellent tumor and ablation probe visualization– multiplanar reformations

• PET/CT: metabolic information + other advantages of CT

Ablation Procedure

• Anesthesia– GA, double lumen T tube, blocker, continuing inflation

• Positioning– tumor side down if possible

– avoid excessive overhead positioning of the arm

• Access– over the rib not below

– avoid transgressing fissures

– avoid ablating pleura, no tract burn

• Multiple tumors– treat tumors at one side at one session Hinshaw JL, Radiographics 2014

Ablation Procedure• To achieve adequate tumor necrosis

ablation needs to include:

– entire tumor &

surrounding parenchyma (ablation margin, >6-10mm)

• adjacent critical structure• aerated lung (insulator)• heat sink

– over lapping ablations to cover large tumors

www.onemedplace.com

Ablation Procedure

• Intraprocedural monitoring

Ablation Procedure

• Intraprocedural monitoring

Ablation Procedure

• Parenchymal hemorrhage

Ablation Procedure

• Pneumothorax

Ablation Procedure

• Pneumothorax

Ablation Procedure

• Post-ablation pneumonia and abscess

Ablation Procedure

• Artificial pneumothorax

Dupuy DE, Radiology 2011

Ablation Procedure

72 yof with a NSCLC who was not a candidate for surgical resection due to severe COPD

• Severe emphysema

Ablation Procedure

• Large tumors

45 yof with breast Ca and solitary RLL met, which was treated by surgically but showed recurrence.

Ablation Procedure

• Central tumors

30-yof with lung metastases from adenoid cystic ca of salivary gland

Ablation Procedure

• Central tumors

77- year-old woman with non-small cell carcinoma (NSCLC)

Ablation Procedure

• Multiple tumors

60-year-old woman metastatic salivary gland adenoid cystic ca

Ablation Procedure

• Multiple tumors

60-year-old woman metastatic salivary gland adenoid cystic ca

Fused Image Monitoring

Ablation Procedure

• Image-registration can be used to visualize the tumor

Planning

Ablation Procedure

• Post XRT recurrence

Post-procedural care• PACU: CXR (2-3 hr), labs (CBC, chem 7, myoglobin)

• Overnight admission to observe

• Next day: CXR, labs (CBC), (CT, MR, PET/CT)

• 1 week follow up clinic visit: analgesia, post ablation syndrome, brown sputum, shortness of breath

• 3, 6, 9, 12 months follow up imaging (CT, MR, PET/CT)

Post ablation, assesment• Assessment of adequacy of ablation

– difficult to differentiate post-ablation changes from residue

– ablated surrounding tissue increases size of treated tumor• completely ablated tumor may appear grown in size (RECIST

criteria is not helpful)

– contrast-enhanced CT is more useful than non-contrast imaging

– MR, PET/CT more sensitive than CECT in detection of viable tumor

Lung Ablation, surveillance

Dupuy D E Radiology 2011

Lung Ablation, surveillanceT1WI post contrast

post contrast (subtracted)

T2WI

T1WIT2WI

Pre-ablation

MRI

Post-ablation

MRI

Lung Ablation, surveillance

• Cavity formation, rare

1 year 6 months 3 months 24-hours

Lung Ablation, surveillance

• Recurrence

pre-ablation

post-ablation

post-ablation(subtracted)

Lung Ablation, effectiveness

• Variable reported outcome – depending on case selection and the method to measure – heterogeneous populations (~50% NSCLC and ~50% mets)

• Over all post-ablation complete tumor necrosis rate – (38% to 91% ; ~63.5 %) (Ambrogi MC, E J of Cardiothoracic Surg 2006)

• Local tumor control at 1year: 88% (Lencioni RR, Clin Oncology 2008)

• Overall survival:• NSCLC at 1, 2, 3, 4, 5 y: 78%, 57%, 36%, 27% & 27%• colorectal mets at 1, 2, 3, 4, 5 y: 87%, 78%, 57%, 57% & 57% (Simon JS, Radiology 2007)

Lung Ablation, effectiveness

De Baere T, Annals of Oncology, 2015

Conclusion

• Image-guided RF ablation is promising treatment option for selected patients with primary or metastatic neoplasm of lungs that are not amenable to surgery

• Careful patient selection and appropriate pre-ablation work up and post ablation surveillance are important factors for satisfactory results

Thank you