SBRT

SBRT IN THE EVERYDAY SBRT IN THE EVERYDAY CLINICAL SETTINGCLINICAL SETTING

William H. Hinson, Ph.D.

Department of Radiation Oncology

Wake Forest University Baptist Medical Center

Winston-Salem, N.C.

SBRT Team at WFUBMCSBRT Team at WFUBMCPhysician

Volker Stieber William Blackstock Kevin McMullen

Physics William H. Hinson William T. Kearns

Whole cast of support staff

Essentials for SBRTEssentials for SBRT

3-D Imaging device Treatment planning system Treatment delivery system Precise targeting (stereotactic coordinate system) Patient positioning verification

Specialized Devices for SBRTSpecialized Devices for SBRT

Novalis Cyberknife Accelerator-based IGRT

(Trilogy, Synergy)

Essentials for SBRTEssentials for SBRT

3-D Imaging device Treatment planning system Treatment delivery system Precise targeting (stereotactic coordinate

system) Patient positioning verification

WFUBMC SBRTWFUBMC SBRT3-D Imaging Device3-D Imaging Device

Phillips PQ 5000 CT simulator

Single slice acquisition External lasers for

isocenter placement AcQSim software

WFUBMC SBRTWFUBMC SBRT“New” 3-D Imaging Device“New” 3-D Imaging Device

GE Discovery ST CT/PET Simulator

8 slice, helical scan, LightSpeed (Ultra) CT scanner

External lasers for isocenter placement

Advantage Simulation Workstation software

WFUBMC SBRTWFUBMC SBRTTreatment Planning SystemTreatment Planning System

Phillips-ADAC 3D RTP system

Accurate small field dosimetry

Standard plan consists of 9 coplanar beams with negative margins

WFUBMC SBRTWFUBMC SBRT

Varian 2100 SCX accelerator

6MV photon beam 120 leaf MLC Portal Vision

WFUBMC SBRTWFUBMC SBRTStereotactic Patient PositioningStereotactic Patient Positioning

Elekta Stereotactic bodyframe

Cartesian coordinate fiducials

Diaphragm breathing control

Patient must pass “YMCA” test

“Treat the box” approach

Stereotactic Patient PositioningStereotactic Patient Positioning

Precise targeting requires a stereotactic coordinate system or image-based targeting

Patient positioning verification is a MUST.

WFUBMC SBRTWFUBMC SBRTPatient Repositioning VerificationPatient Repositioning Verification

Elekta bodyframe lasers (2 chest points plus leg marker

Serial CT image sets on day of simulation

“GTV” is defined from the fusion of 2 image sets (i.e. “4-D GTV”)

WFUBMC SBRTWFUBMC SBRTPatient Repositioning VerificationPatient Repositioning Verification

On day of treatment - SSD checks and orthogonal isocenter portal images

Physician approval of isocenter images required before treatment proceeds.

Total time on linac is about 1 to 1.5 hours

WFUBMC SBRTWFUBMC SBRTOrthogonal Portal ImagesOrthogonal Portal Images

Fraction #1

Fraction #2

Fraction #3

WFUBMC SBRTWFUBMC SBRTPatient Positioning VerificationPatient Positioning Verification

Neuro-surgical Stealth Station computer system

Stereo IR camera Fiducials placed on SBF

and patient System detects shifts in

patient, relative to the SBF

WFUBMC SBRTWFUBMC SBRTPatient Positioning VerificationPatient Positioning Verification

Patient No.

GTV Isocenter shift (mm)*

Stealth Station RMS Error (mm)

1 3.7 0.7

2 4.1 1.5

3 3.0 0.6

4 6.7 0.8

*Shifts mainly in axial direction on 3mm thick slices.

WFUBMC SBRTWFUBMC SBRT

Through March, 2005, 70 SBRT patients have been treated using the Elekta Bodyframe.

Of these 70 patients, 30 patients have been treated in a single fraction on our Stereotactic Body Radiosurgery protocol.

Others have received between 2 and 4 fractions.

WFUBMC SBRS PROTOCOLWFUBMC SBRS PROTOCOL

CCCWFU 99502: “A Phase I/II Dose-Escalation/Efficacy Study of Palliative Extracranial Radiosurgery using the

Elekta Stereotactic Body Frame System.”

Eligibility criteria:Eligibility criteria: The presence of a well-circumscribed tumor (primary or The presence of a well-circumscribed tumor (primary or

metastatic) on contrast-enhanced CT scan with a maximum metastatic) on contrast-enhanced CT scan with a maximum diameter of 6 cm. diameter of 6 cm.

Age Age 18 years with a life expectancy 18 years with a life expectancy 3 months. 3 months. No chemotherapy or immunotherapy were allowed at least 3 No chemotherapy or immunotherapy were allowed at least 3

weeks prior to or planned for 4 weeks after treatment. weeks prior to or planned for 4 weeks after treatment.


Dose (Gy)

Tumor Volume Stratification

Small< 25 cm3

Medium25 cm3 65 cm3

Large65 cm3 - 120 cm3

Phase I 15 → 22.5 → 32.4 12 → 18 → 28.5 10 → 15 → 20

Phase II 13 → 22.5 10 → 18 → 22.5 8 → 15 → 20

Patients were stratified to dose levels by tumor volume

Phase I Endpoint: Acute toxicity using NCI Common Toxicity Criteria 3.0 Phase II Endpoint: Local control by CT RECIST Criteria (Response Evaluation

Criteria In Solid Tumors)


28 patients have been enrolled on study. 12 (43 %) 28 patients have been enrolled on study. 12 (43 %) of these patients have had PET imaging for a of these patients have had PET imaging for a minimum of 3 months. We report the results of minimum of 3 months. We report the results of these patients. these patients.

For the PET group, median follow-up so far is 377 For the PET group, median follow-up so far is 377 days (171-739 days). Median survival has not yet days (171-739 days). Median survival has not yet been reached. 3 deaths have occurred. For these been reached. 3 deaths have occurred. For these 3 patients, median survival from time of treatment 3 patients, median survival from time of treatment was 250 days. was 250 days.


Local control at 3 months was 100 %. Local control at 3 months was 100 %. The median change in tumor diameter at 3 months The median change in tumor diameter at 3 months

was -14 % (-59% to 0 %) for a median RECIST of was -14 % (-59% to 0 %) for a median RECIST of SD. SD.

The median corrected SUV change at 3 months The median corrected SUV change at 3 months was -57 % (-13% to + 11%).was -57 % (-13% to + 11%).

WFUBMC SBRS PROTOCOLWFUBMC SBRS PROTOCOL 8 patients have had no progressive disease (PD). 8 patients have had no progressive disease (PD). For 7/8, the SUV decreased and had not increased by the last For 7/8, the SUV decreased and had not increased by the last

follow-up.follow-up. 4 patients have had 4 patients have had PDPD by RECIST. by RECIST. 3/4 had a corresponding rise in correct SUV, which preceded the 3/4 had a corresponding rise in correct SUV, which preceded the

RECIST progression by a median of 71 days (71-75 days).RECIST progression by a median of 71 days (71-75 days). The median time to RECIST failure for these patients was 238 The median time to RECIST failure for these patients was 238

days (175-319 days). days (175-319 days). Overall, the correlation between RECIST control and PET Overall, the correlation between RECIST control and PET

control was 0.71.control was 0.71.


In the In the acuteacute phase (< 3 months), there appears to phase (< 3 months), there appears to be no significant inflammatory response by PET. be no significant inflammatory response by PET.

In the In the latelate phase, (> 3 months) PET progression phase, (> 3 months) PET progression appears to precede RECIST PD by 2.4 months. appears to precede RECIST PD by 2.4 months. This may have implications for the timing of This may have implications for the timing of subsequent therapy (e.g. chemotherapy).subsequent therapy (e.g. chemotherapy).

POSSIBLE IMPROVEMENTSPOSSIBLE IMPROVEMENTS

Respiratory gatingRespiratory gating On-board KV imagingOn-board KV imaging Cone beam imagingCone beam imaging

THANK YOUTHANK YOU

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