Potential Non-Gantry Solutions for Isocentric Patient Irradiation - PowerPoint PPT Presentation

Potential Non-Gantry Solutions for Isocentric Patient Irradiation with Heavier Ions Rich Levy, M.D, Ph.D. ABC Foundation Formerly: Medical Scientist, LBNL Professor of Rad Onc, LLUMC

Outline • “Isocentric”: Definition and Concepts • Stereographic 2D Projections of Sphere • Beam Entry Access Angles for a Sphere • Traditional Fixed Horizontal Beam • Traditional Gantry Beam • Potential of Fixed Vertical & 45 º Beams • Potential of Isocentric Patient Positioner • Internal Fiducials Feedback • Be a Rocket Scientist!

“Isocentric” Definitions and Concepts • Six Degrees of Freedom • X, Y, Z -- traditional orthogonal axes • Roll, Yaw, Pitch -- rotational deviation • Roll -- about the horizontal axis parallel to the long axis of the body • Yaw -- about the vertical axis • Pitch -- about the horizontal axis perpendicular to long axis of the body

Isocentric Table: STAR Beam Access Entry Angles Axial Sagittal Coronal Axial Sagittal Coronal (roll) (pitch) (yaw) (roll) (pitch) (yaw)

Isocentric Table: STAR Beam Access Entry Angles Axial Sagittal Coronal Axial Sagittal Coronal (roll) (pitch) (yaw) (roll) (pitch) (yaw)

Equatorial (lateral) and Polar (superior) Stereographic Projection (2D) Views of the Earth Lateral View Superior View

Projections of Lateral and Superior Views of Sphere: Cartesian and Spherical Coordinates z Superior z Lateral 2D View Projection P “Polar” angle P (latitude) Azimuthal angle (longitude) O y x Lateral View Superior 2D Projection x z

Equatorial (lateral) and Polar (superior) Stereographic Projection (2D) Views of the Earth Lateral View Superior View

Lateral View: Spherical Beam Vector Access + 90 º = Non-Access z Isocenter A = 4 π r 2 y x 0 º Equator (Horizontal Vertical (y) Axis) (z)Axis - 90 º

Superior View: Spherical Beam Vector Access = Non-Access y Isocenter x A = 4 π r 2 x z 180 º 90 º 0 º Vertical (z) Axis Equator (Horizontal (x) Axis) •

Lateral View: Spherical Beam Vector Access + 90 º Complete Beam Access z Isocenter = Access A = 4 π r 2 y x 0 º Equator (Horizontal Vertical (y) Axis) (z)Axis - 90 º

Superior View: Spherical Beam Vector Access Complete Beam Access y Isocenter x = Access A = 4 π r 2 x z 180 º 90 º 0 º Vertical (z) Axis Equator (Horizontal (x) Axis) •

Lateral View: Fixed Horizontal Beam Access + 90 º Horizontal axis roll: ±0º Vertical axis yaw: 360º = Access = Non-Access Horizontal Beam ± 0 º Roll 0 º Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Superior View: Fixed Horizontal Beam Access Horizontal axis roll: ±0º Vertical axis = Access x yaw: 360º = Non-Access Horizontal Beam ± 0 º Roll 180 º 90 º 0 º Isocenter Vertical Equator (z) Axis (Horizontal Axis) •

Lateral View: Traditional Gantry Beam Access + 90 º Horizontal axis roll: 360º Vertical axis yaw: ±0º Gantry Beam = Access = Non-Access ± 0 º Yaw 360 º Isocenter 0 º Equator (Horizontal Axis)

Superior View: Traditional Gantry Beam Access + 90 º Horizontal axis roll: 360º Vertical axis yaw: ±0º Gantry Beam = Access = Non-Access ± 0 º Yaw 360 º 0 º Isocenter Equator (Horizontal Axis)

Lateral View: Traditional Gantry + Table Rotation + 90 º Combined Beam Access Independent Horizontal axis roll: 360º & = Access Vertical axis = Non-Access yaw: 360º 0 º Isocenter Vertical Equator (z)Axis (Horizontal Axis) - 90 º

Superior View: Traditional Gantry + Table Rotation Combined Beam Access x Independent Horizontal axis roll: 360º & = Access Vertical axis = Non-Access yaw: 360º 90 º 180 º 90 º 0 º Isocenter Vertical Equator (z) Axis Horizontal Axis •

Lateral View: Fixed Horizontal Beam Access (±0º Roll) + 90 º Horizontal axis roll: ±0º Vertical axis yaw: 360º = Access = Non-Access Horizontal Beam ± 0 º Roll 0 º Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Lateral View: Fixed Horizontal Beam Access (±15º Roll) Horizontal axis + 90 º roll: ±15º + 75 º Vertical axis + 60 º yaw: 360º = Access = Non-Access + 30 º + 15 º Horizontal Beam ± 15 º 0 º Roll Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Superior View: Fixed Horizontal Beam Access (±15º Roll) Horizontal axis Horizontal Beam ± 15 º roll: ±15º Roll Vertical axis x yaw: 360º = Access = Non-Access 30 º 60 º 75 º 0 º 15 º 90 º Isocenter Vertical Equator Axis (Horizontal Axis) •

Lateral View: Fixed Combo H/V Beams Access (±15º Roll) Horizontal axis + 90 º Vertical Beam ± 15 º roll: ±15º + 75 º Roll Vertical axis + 60 º yaw: 360º = Access = Non-Access + 30 º + 15 º Horizontal Beam ± 15 º 0 º Roll Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Superior View: Fixed Combo H/V Beams Access (±15º Roll) Horizontal axis Horizontal Beam roll: ±15º ± 15 º Roll Vertical axis x yaw: 360º = Access = Non-Access Vertical Beam ± 15 º Roll 30 º 60 º 75 º 0 º 15 º 90 º Vertical Isocenter Equator Axis (Horizontal Axis) •

Lateral View: Fixed Combo H/V/45º Beams Access (±15º Roll) + 90 º Horizontal axis Vertical Beam ± 15 º roll: ±15º + 75 º Roll Vertical axis yaw: 360º + 60 º 45 º Beam ± 15 º Roll = Access + 30 º = Non-Access + 15 º Horizontal Beam ± 15 º 0 º Roll Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Superior View: Fixed Beams Horizontal axis Horiz Beam ± 15 º Roll roll: ±15º Vertical axis x yaw: 360º 45 º Beam ± 15 º Roll = Access = Non-Access Vertical Beam ± 15 º Roll 0 º 15 º 30 º 60 º 75 º 90 º Isocenter Vertical Equator Axis (Horizontal Axis) •

Isocentric T able: STAR Rolled Position for Oblique Fields T ext 45º Roll 90º Roll Brain: ~No organ motion! Reliable fiducials!

Isocentric T able: STAR Rolled Position for Oblique Fields T ext 45º Roll 90º Roll Other Target Volumes: Organ Motion? Roll Effects?

Organ Motion, Roll Effects and Beam Scanning • Organ Motion? • Hearts beat, Lungs breathe • Diaphragm moves, GI has tract peristalsis • Roll Effects on Target Volume • Is supine the only reproducible position? • ±15º or decubitus position (±90º) roll? • Distortion of target volume? • Rx planning scan in Rx position(s)? • Beam Scanning • Must recognize and account for motion • Internal target volume, critical organs? • Fiducials: anatomic & implanted (Au, RF) • Hardware Mounting: Fixed vs Gantry?

Lateral View: Fixed Beams Horizontal axis + 90 º Vert Beam ± 22.5 º roll: ±22.5º + 75 º Vertical axis Roll yaw: 360º + 60 º 45 º Beam ± 22.5 º Roll = Access + 30 º Added = Non-Access Access + 15 º Horizontal Beam ± 22.5 º Roll 0 º Isocenter Equator 360 º Vertical (Horizontal Axis) Axis

Craniospinal Irradiation with X-Rays Pediatric, Prone, ± Intubation

Craniospinal Irradiation: Medulloblastoma LET’S DO IT! Bussiere and Adams, 2003 31

Lateral View: Fixed Beams Horizontal axis + 90 º Vert Beam ± 22.5 º roll: ±22.5º + 75 º Vertical axis Roll yaw: 360º + 60 º 45 º Beam ± 22.5 º Roll = Access + 30 º Vertical Added = Non-Access Access 360 º Axis + 15 º Horizontal Beam ± 22.5 º Roll 0 º Isocenter Equator 45 º Beam ± 22.5 º Roll (Horizontal Axis) Vert Beam ± 22.5 º Prone Position

Superior/Inferior Views: Fixed Beams Horizontal axis Horizontal Beam roll: ±22.5º ± 22.5 º Roll Vertical axis yaw: 360º x 45 º Beam ± 22.5 º Roll = Access Added = Non-Access Access Vertical Beam ± 22.5 º Roll 0 º 15 º 30 º 60 º 75 º 90 º Vertical Isocenter Equator Axis (Horizontal Axis) •

Lateral View: Spherical Beam Vector Access + 90 º Complete Beam Access z Isocenter A = 4 π r 2 y = Access = Non-Access x 0 º Equator (Horizontal Vertical (y) Axis) (z)Axis - 90 º

Sup/Inf Views: Spherical Beam Vector Access Complete Beam Access y Isocenter x A = 4 π r 2 x = Access = Non-Access z 180 º 90 º 0 º Vertical (z) Axis Equator (Horizontal (x) Axis) •

ISAH: LBNL, 1950s (p+ and He) 36

Proton Tx Harvard Cyclotron Lab (Early 1960’s) 37

LET’S DO IT! 38

HCL Radiosurgery Pre-1991 STAR: 1991-2001

Isocentric T able: STAR R2 Z Y X R1

Isocentric T able: STAR

Isocentric T able: STAR

Isocentric T able: STAR

Isocentric Table: STAR Beam Access Entry Angles Axial Sagittal Coronal (roll) (pitch) (yaw)

STAR: 6-FIELD RX Beams: RL, LL, LAO, RPO, SUP, SAO

Conclusions (I) • Broad Range of Beam Entry Angles with: • Fixed H/V and 45 º beams • Isocentric tables with • 360º yaw (about vertical axis) • ±15-22.5º roll (about horiz axis) • supine & prone positioning

Conclusions (II) • Obtain Treatment Planning Scans in Anticipated Angle(s) of Roll Rotation • Verify Position via Internal Fiducials • Gantries Make Treatment Easier ... • But lack of one is NOT a show-stopper! • Even gantries NEED isocentric tables! • Beam Scanning is the Real Deal • BE A ROCKET SCIENTIST!