Stereotactic Radiosurgery for Lung Cancer
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STEREOTACTIC RADIOSURGERY FOR LUNG
CANCER
Robert Sinha, M.D.Radiation Oncologist
Western Radiation OncolgyDorothy Schneider Cancer Center
Lung Cancer: The Problem
Incidence: Estimated 226,160 new cases in 2012
Mortality: Estimated 160,340 deaths in 2012
Survival by stage
Stage TNM 5-yr OS Literature**
IA-IB T1-T2N0M0 60-80%
IIA-IIB T1-T2N1M0 25-50%
IIIA T3N0-N1 or T1-3N2
10-40%
IIIB Any T4 or any N3
5%
IV M1=distant mets
<5%
**John D. Minna, Neoplasms of the Lung, in Harrison’s Principles of Internal Medicine, pt. 5 § 75, at 506-515 (Dennis L. Kasper, M.D. et al., eds, 16th ed 2005).
Survival: Only 15-20% of all lung cancer patients (all stages) will be alive 5 years after dx
Role of Radiotherapy
Palliation of symptoms for advanced disease Brain and bone mets, local symptoms
Curative Intent in Stage IIIA and IIIB disease 5 year survival rates of 10 to 30%
Curative Intent for medically inoperable patients Local control with traditional radiotherapy: 25-30%% New techniques like SBRT have local control ~ 90%
Radiotherapy in the 1970s to the 1990s
Step 1: Conventional simulator: diagnostic quality xrays to design fields
Step 2: Fabricate custom cerrobend blocks
Step 3: Perform Dose Calculations
Step 4: Treat patient on linac with mounted blocks
Typical radiation portal for lung cancer
Late 1990s to 2000s
CAT scan based planning 3 Dimensional conformal Therapy IMRT – Intensity Modulated Radiotherapy IGRT – Image Guided Therapy
3D conformal and IMRT: What did we achieve?
• Accuracy• Less side effects – normal tissue sparing• Dose escalation (60Gy to 70-74Gy)
Challenges
Target definition Target Motion
Respiratory motion/tracking Normal tissue tolerance/Increasing dose
Conventional XRT limited to 70Gy Duration of therapy
6 to 7 weeks for conventional therapy is difficult for medically inoperable patients
Highly focused radiation concentrated on the tumor – with sub-millimeter accuracy
Continuous tumor tracking – via respiratory gating Typically 5 or less treatments– high dose per
treatment Biologic Equivalent doses greater than 120Gy at
2Gy/fx
Stereotactic Body Radiosurgery (SBRT):The Ultimate “Targeted Therapy”
Challenge #1: Target Definition
Treatment Planning PET-CT scans
Time of Flight PET/CT
Challenge #2: Target MotionSolution: Respiratory Gating
Challenge #3: Normal Tissue Sparing
Stereotactic hypofractionated high-dose irradiation for stage I non-small cell lung carcinoma: Clinical outcomes in 281 cases of a Japanese multi-institutional
study
14 Institutions in Japan from 1993 to 20033yr OS 69% when BED>100 Gy3yr OS for “operable” patients = 81% when BED> 100
Stage I “Operable” NSCLC: Japanese Experience
IAIB
Baumann, P. et al. J Clin Oncol; 27:3290-3296 2009
• 57 patients• Median age 75• 90% inoperable due to COPD/CAD• 30% T2; 51% T1b; 19% T1a• Dose: 45Gy in 3 fxs (BED 113)
• Local control at 3yrs = 93%• Distant mets at 3yrs = 16%
• Overall survival @ 3yrs = 60%• DSS @ 3yrs = 88%
Scandinavian Study:
• 59 patients• Median age 72• All pts inoperable• T1 – 80%; T2- 20%• Dose: 60Gy in 3 fxs (BED 180)
Median FU 3 yrs:• Local control = 97.6%• Distant mets = 22.1%
• Overall survival @3yrs = 55.8%
• Median survival = 48 months
RTOG 0236:
• Lancet 2012
• 676 Patients, single institution
• Stage I and II patients
• 3 year survival 56%• Median survival: 41 months
• Local Control @5yrs – 90%• Distant mets@5yrs – 20%
Local Control for Primary NSCLC by Dose Fractionation Schemes
Historical Surgical Survival Stage I NSCLC
50-80%
Case Study: NSCLC Left Upper Lung
DEMOGRAPHICS & HISTOLOGY 76 yo Female, 1 month non-productive cough, mass on
CXR CT and PET show no other areas of disease Histology: Poorly differentiated non-small cell lung
carcinoma with squamous features . PET/CT staged as cT1N0M0 stage grouping IA
CLINICAL HISTORY: Referred by: Pulmonologist Previous Treatment: None Multiple medical co-morbidities (FEV1=1.12)
NSCLC Left Upper LungPreOp CT and Fiducial Placement: 1.0 mm CT slices with 1.5x2.0x2.1 cm tumor 4 fiducials are placed within and near the
tumor
TREATMENT PLANNING: • Axial, sagittal and coronal planning images showing the
tumor, lung parenchyma and isodose curves
NSCLC Left Upper Lung
TREATMENT DETAILS:• Rx Dose & Isodose: 60 Gy to 71%, 3 fractions QOD.• Tumor volume = 13.85 cc• Conformity Index (PIV/TV) = 1.37
RESULTS: • Near CR on CT 12 weeks post-treatment, PET negative at 3
months• PFTs unchanged at 3 months• Patient is NED at 3 years
Pre-treatment 3 months post
treatment
NSCLC Left Upper Lung
Solitary Lung Metastasis from Esophageal SCC
Demographics:• 67 yo s/p GTR resection 18 months prior, CAD &
FEV1=1.13 • Patient refused surgery after previous RML surgery
Solitary Lung Metastasis from Esophageal SCC
Pre-Treatment 1 mo post-CK 2 mo post-CK 6 mo post-CK
• Stable PFT’s & negative PET/CT >24 months after SBRT
Rx 54 Gy to 85% isodose in 3 fractions
Rusthoven, K. E. et al. J Clin Oncol; 27:1579-1584 2009
Fig 1. Images from a right lower lobe (RLL) lesion before and after stereotactic body radiation therapy (SBRT)
Pre - tx Post tx
• 38 patients with 63 lesions• Dose: 48 to 60Gy in 3fxs• Tumor volume included ITV, i.e. total
migration of tumor
• Local control at 2yrs = 96%• Median survival = 19 mo.
• Grade 3 toxicity 8% (almost all skin)• 1 case of symptomatic pneumonitis
Rusthoven, K. E. et al. J Clin Oncol; 27:1579-1584 2009
Fig 2. Actuarial local control in assessable patients
Why SBRT for Metastatic Disease?
Systemic therapies are improving, prolonging survival
But, systemic therapy still can’t durably control GROSS DISEASE (perhaps never will)
Residual disease can “re-seed” SBRT: A minimally toxic yet potent local
therapy to consolidate all gross disease
Summary
SBRT is emerging as the new “standard of care” for medically inoperable early stage NSCLC patients
Early data suggest that it may also achieve high local control and survival rates in operable patients
SBRT is a promising treatment modality for patients with oligiometastatic dz to the lung.
Future Directions
Randomized comparison of Surgery vs SABR for operable patients ACOSOG Z4099/RTOG 1021 – Wedge vs SABR STARS Trial – Lobectomy vs SABR for Stage I
Can adjuvant systemic therapy improve outcomes for early stage inoperable patients?
CALGB/RTOG – SABR +/- chemo for 2-5cm T1 tumors
Thank You
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