DEPT OF RADIATION ONCOLOGY DEPT OF RADIATION ONCOLOGY Stereotactic Body Radiotherapy (SBRT) for the Inoperable Early Stage Lung Cancer Patient Lucien A. Nedzi, M.D. Lucien A. Nedzi, M.D. Department of Radiation Oncology Department of Radiation Oncology Univ. of Texas Southwestern Medical Univ. of Texas Southwestern Medical Center Center
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Stereotactic Body Radiotherapy (SBRT) for the Inoperable Early Stage Lung Cancer
Patient
Lucien A. Nedzi, M.D.Lucien A. Nedzi, M.D.
Department of Radiation OncologyDepartment of Radiation Oncology
Univ. of Texas Southwestern Medical CenterUniv. of Texas Southwestern Medical Center
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Early Stage Lung Cancer Risk Groups
3 broad groups:3 broad groups: Average RiskAverage Risk
Generally can tolerate removal of Generally can tolerate removal of an entire lobean entire lobe
High RiskHigh Risk
Can tolerate partial removal of a Can tolerate partial removal of a lobelobe
Medically Medically InoperableInoperable
Cannot tolerate surgery for lung Cannot tolerate surgery for lung cancercancer
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Circa 1995: A new treatment called “Extracranial
Stereotactic Radioablation” (later SBRT)
• GammaKnife-like treatments in the bodyGammaKnife-like treatments in the body
• Swedish pioneers Ingmar Lax and Henric Swedish pioneers Ingmar Lax and Henric BlomgrenBlomgren
• Japanese pioneer Minoru UematsuJapanese pioneer Minoru Uematsu
• Facilitated by technology (immobilization, Facilitated by technology (immobilization, motion control, 3-D dosimetry, image-motion control, 3-D dosimetry, image-guidance)guidance)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
What Characterizes Stereotactic Body Radiation
Therapy (SBRT)?
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Spread out the entry radiation damage
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Punishing Radiation Target Dose
-This dose defines tumor control (place it well)This dose defines tumor control (place it well)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Steep Radiation Gradients to Normal Tissue
-This intermediate dose This intermediate dose -Can kill microscopic tumor tentaclesCan kill microscopic tumor tentacles-BUT, accounts for toxicity. BUT, accounts for toxicity.
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Very large low dose radiation volume
- SBRT (and radiosurgery) Assumption: A little dose to a lot of - SBRT (and radiosurgery) Assumption: A little dose to a lot of normal tissue is better than a lot of dose to a little normal tissuenormal tissue is better than a lot of dose to a little normal tissue
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
SBRT Treatment Logistics
OutpatientOutpatient
No Sedation orNo Sedation orAnesthesiaAnesthesia(painless)(painless)
Entire course ofEntire course ofRx in 1-2 weeksRx in 1-2 weeks
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Tissue Effects After SBRT• Dramatic tumor responses even in solid organsDramatic tumor responses even in solid organs• Solid organ–sloughing unlikely contributing to Solid organ–sloughing unlikely contributing to
responseresponse• Implies SBRT preserves competence of immune Implies SBRT preserves competence of immune
system to carry out phagocytosissystem to carry out phagocytosis
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Tissue Effects After SBRT• Normal tissue collateral damage does occurNormal tissue collateral damage does occur
Dose and location dependantDose and location dependant Adjacent tissue doesn’t function (ablated)Adjacent tissue doesn’t function (ablated)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Summary of SBRT• Very convenient and non-invasiveVery convenient and non-invasive
• Technology intensive and dependantTechnology intensive and dependant
• In contrast to CFRT, local immune function appears In contrast to CFRT, local immune function appears mostly preservedmostly preserved Dramatic tumor responsesDramatic tumor responses Avoidance of necrosisAvoidance of necrosis
• Immediately surrounding normal tissue is damaged Immediately surrounding normal tissue is damaged to the point of dysfunctionto the point of dysfunction Decreased organ reserve (?symptomatic)Decreased organ reserve (?symptomatic)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
*clinically staged and mostly medically inoperable *clinically staged and mostly medically inoperable (some refused surgery)(some refused surgery)
Conventional RT generally 60-66 Gy delivered in 6-7 Conventional RT generally 60-66 Gy delivered in 6-7 weeksweeks
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Early Investigations of SBRT
• Mostly ad hoc, retrospectiveMostly ad hoc, retrospective
• Treated typical drug discovery phase I Treated typical drug discovery phase I populationpopulation Incurable patientsIncurable patients Metastatic cancerMetastatic cancer Near end of lifeNear end of life
• Difficult to draw conclusionsDifficult to draw conclusions
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
SBRT in Early Stage NSCLC• First prospective trials were in medically First prospective trials were in medically
inoperable patients with stage I NSCLCinoperable patients with stage I NSCLC Those refusing surgery (confounders) not Those refusing surgery (confounders) not
allowedallowed
• Intent, originally, was to improve tumor Intent, originally, was to improve tumor controlcontrol probably at the expense of increased toxicityprobably at the expense of increased toxicity
• Experience has been that tumor control is Experience has been that tumor control is improved and treatment is surprisingly well improved and treatment is surprisingly well toleratedtolerated
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
• Classic phase I designClassic phase I design• Low starting dose 8 Gy X 3 = 24 GyLow starting dose 8 Gy X 3 = 24 Gy• Dose escalation to very high doses Dose escalation to very high doses
20-24 Gy X 3 = 60-72 Gy20-24 Gy X 3 = 60-72 Gy
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Tumor Control Definitions
• Follow-up policy and control definitions:Follow-up policy and control definitions: CT scan q3 monthsCT scan q3 months Progressive CT consolidation within or adjacent Progressive CT consolidation within or adjacent
to tumor prompt PETto tumor prompt PET If PET has uptake similar to initial staging If PET has uptake similar to initial staging
(EORTC criteria), then score as tumor (EORTC criteria), then score as tumor recurrencerecurrence
Otherwise continue to follow (NED)Otherwise continue to follow (NED)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
72 yo female with T1N0M0 NSCLC s/p SBRT 54Gy/3 fractions to 73% dose line,
dose at iso=73.97Gy, 10 beams
Example
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Treatment Plan
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Follow-up• 3 month scan with good response3 month scan with good response• 6 months post SBRT develops cough, fever, 6 months post SBRT develops cough, fever,
SOB, and chest wall painSOB, and chest wall pain
• Original PET SUV 9-10, repeat PET SUV 3-5Original PET SUV 9-10, repeat PET SUV 3-5
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Follow-up• Treated with incentive spirometry, Treated with incentive spirometry,
prednisone taper, albuterol nebulizers for prednisone taper, albuterol nebulizers for pneumonitispneumonitis
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Local Control
• Local recurrence is primary tumor failure Local recurrence is primary tumor failure and/or failure within the involved lobe of and/or failure within the involved lobe of the lungthe lung
• 1 patient had primary tumor failure1 patient had primary tumor failure ++
3 patients had failure within the involved 3 patients had failure within the involved lobelobe
• 3-year Kaplan Meier local control = 90.7%3-year Kaplan Meier local control = 90.7%
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Regional Recurrence
• 2 patients have reported a regional failure, 2 patients have reported a regional failure, both after 2 years (2.8 and 3.0 years)both after 2 years (2.8 and 3.0 years)
• Patients avoiding both local and regional Patients avoiding both local and regional recurrence (loco-regional control) is 87.2%recurrence (loco-regional control) is 87.2%
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Disseminated Recurrence
• Eleven patients (20%) have experienced Eleven patients (20%) have experienced disseminated failuredisseminated failure 8 of these patients had failure prior to 2 8 of these patients had failure prior to 2
yearsyears
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Overall Survival
OverallSurvival(%)
0
25
50
75
100
MonthsafterStartofSBRT0 6 12 18 24 30 36
0
25
50
75
100
0 6 12 18 24 30 36
PatientsatRisk 55 54 47 46 40 35 24
Dead: 26Total: 55
MST: 48.1(95%CI): (29.6,notreached)
/// / / //36 month
overall survival = 56% (CI: 42-68%)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Severe Toxicity• No grade 5 toxicities (treatment No grade 5 toxicities (treatment
deaths)deaths)
• Two (4%) grade 4 protocol specified Two (4%) grade 4 protocol specified toxicity (decline in PFTs to <25% toxicity (decline in PFTs to <25% predicted & hypocalcemia)predicted & hypocalcemia)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
• SBRT has become a standard of care for SBRT has become a standard of care for medically inoperable patientsmedically inoperable patients No randomized trial deemed necessaryNo randomized trial deemed necessary Up to 10,000 patients per year in USUp to 10,000 patients per year in US
• Successful clinical model using Successful clinical model using hypofractionated radiotherapy:hypofractionated radiotherapy:• Rigorously conducted, highly scrutinizedRigorously conducted, highly scrutinized• Multicenter QAMulticenter QA• Rapid acceptanceRapid acceptance
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Multicenter Phase II Trials Medically Inoperable
• Dutch InvestigatorsDutch Investigators 206 patients with Stage I206 patients with Stage I Risk adapted approach well toleratedRisk adapted approach well tolerated Primary tumor recurrence 3%, regional failure 9%, 2 Primary tumor recurrence 3%, regional failure 9%, 2
year OS 64%year OS 64%
• JCOG 0403JCOG 0403 Peripheral T1a, N0, M0Peripheral T1a, N0, M0 100 patients – still enrolling100 patients – still enrolling
• Nordic Study GroupNordic Study Group peripheral T1-T2, N0, M0peripheral T1-T2, N0, M0 completed accrual of 57 patients 9/2005completed accrual of 57 patients 9/2005 Primary tumor recurrence 7%, 2 year OS 65%Primary tumor recurrence 7%, 2 year OS 65%
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Future Directions• Refine SBRT for medically inoperable patientsRefine SBRT for medically inoperable patients
Refine dose constraints with dosimetry databases Refine dose constraints with dosimetry databases and patient outcomesand patient outcomes
Refine dose prescription comparing various Refine dose prescription comparing various fractionation regimens (RTOG 0915)fractionation regimens (RTOG 0915)
Refine dose prescription for centrally located Refine dose prescription for centrally located tumors via phase I trial (RTOG 0813)tumors via phase I trial (RTOG 0813)
Refine therapy in combination with systemic Refine therapy in combination with systemic therapiestherapies
• Explore use of SBRT in an operable patient Explore use of SBRT in an operable patient subset (RTOG 0618) subset (RTOG 0618)
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Patients randomized to SBRT will receive 18Gy in three fractions, for a total dose of 54Gy. Brachytherapy is allowed with SR.All registered patients will be followed for study endpoints, regardless of the status of their treatment. That includes patients receiving adjuvant therapy for any reason.
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Conclusions• SBRT for lung cancer is effective and tolerableSBRT for lung cancer is effective and tolerable
Prospectively studiedProspectively studied Encouraging and reproducible resultsEncouraging and reproducible results Admittedly imperfect therapy with both failure and Admittedly imperfect therapy with both failure and
harmharm
• SBRT is an established standard therapy for SBRT is an established standard therapy for medically inoperable patientsmedically inoperable patients
• SBRT should be compared to less invasive/less SBRT should be compared to less invasive/less radical surgery in high risk operable patientsradical surgery in high risk operable patients Momentum extremely strong for SBRT, but ideally Momentum extremely strong for SBRT, but ideally
studies will be donestudies will be done
DEPT OF RADIATION ONCOLOGYDEPT OF RADIATION ONCOLOGY
Acknowledgements
• UTSW Rad OncUTSW Rad Onc Robert Timmerman, M.D.Robert Timmerman, M.D. Hak Choy, M.D.Hak Choy, M.D. Ramzi Abdulrahman, M.D.Ramzi Abdulrahman, M.D. Lech Papiez, Ph.D.Lech Papiez, Ph.D. Timothy Solberg, Ph.D.Timothy Solberg, Ph.D.
• UTSW CT SurgeryUTSW CT Surgery Michael Wait, M.D.Michael Wait, M.D. Michael Dimiao, M.D.Michael Dimiao, M.D.
• UTSW Med OncUTSW Med Onc Joan Schiller, M.D.Joan Schiller, M.D. David Gerber, M.D.David Gerber, M.D.
• RTOG HeadquartersRTOG Headquarters Rebecca Paulus, Ph.D.Rebecca Paulus, Ph.D. Linda Walters, M.S.Linda Walters, M.S.