Concepts of motion management

in radiation therapy

: Physician perspectives

(Challenges and pitfalls)

Dr. Jiraporn Setakornnukul

Outline

Basic organ motion • Organ motion

• ICRU definition

• Intra-interfraction

Motion management technology

Clinical outcome

Challenges and Pitfalls

Goal for motion management in radiotherapy

Technical outcome Clinical outcome

Set-up error Surrogate outcomes

Inter-fraction organ motion • Tumor response/control

Intra-fraction organ motion • Toxicities

Patient compliance Secondary outcomes

Learning curve • Quality of life

Primary outcomes

• Overall survival

J Med Phys. 2012 Oct-Dec; 37(4): 174–182.

ICRU definition of volume PTV

• Internal margin: account for variations in size, shape, and position of the CTV

• Setup margin: account for uncertainties in patient position and beam alignment

Human organ motion

Voluntary motion • Musculoskeletal system (striated muscle)

Physiologic organ motion • Periodic motion: breathing, cardiac motion

• Non-periodic motion: bladder/rectal filling, stomach

• Quasi-periodic motion: peristaltic movement of bowel

Internal margin

INTERFRACTION ORGAN MOTION • CTV position changes on day-to-day level

• Main: gynecologic ca, prostate ca, bladder ca, rectal ca

• INTRAFRACTION ORGAN MOTION • occurs while the patient is being irradiated

• Main: lung, liver, breast, kidney, pancreas

Depend on technique of Radiotherapy

Photon

• 3D-CRT

• IMRT/VMAT

• SBRT

Particle beam radiotherapy

• Proton therapy

• Heavy ion

Organ motion in Pelvic region: Interfraction

Semin Radiat Oncol 18:58-6

PTV margin in prostate cancer

Semin Radiat Oncol 18:58-6

Intrafraction

Semin Radiat Oncol 18:58-6

Organ motion in thoracic region: Intrafraction

Respiratory motion management (AAPM)

• Motion-encompassing methods

• Respiratory gated techniques

• Breath-hold techniques

• Forced shallow-breathing methods

• Respiration-synchronized techniques

Motion management technologies

2D-image KV & MV port KV & MV port Stereoscopic orthogonal image

Stereoscopic orthogonal image

3D-image CBCT/CT-on rail CBCT

Motion management technologies

SGRT

External surrogate

Motion management technologies

Gating/ Tracking system

Calypso system and Beacon (KIM*)

(KIM*)

Fiducial implant Lung tracking

*Kilovoltage intrafraction monitoring

Motion management technologies (MRgRT)

Ultrasound

Goal for motion management in radiotherapy

Technical outcome Clinical outcome

Set-up error Surrogate outcomes

Inter-fraction organ motion • Tumor response/control

Intra-fraction organ motion • Toxicities

Patient compliance Secondary outcomes

Learning curve • Quality of life

Primary outcomes

• Overall survival

J Med Phys. 2012 Oct-Dec; 37(4): 174–182.

Early stage NSCLC: Medically inoperable

Dose 60 Gy/30F

SBRT : 60 Gy in 8 fractions (7.5Gy/F), BED 105

Outcome: SBRT/SABR in ES-NSCLC

Authors Patient Dose(Gy) Stage 3 yr Local Control (%)

3 yr Overall Survival (%)

5 yr OS 5 yr LC

Prospective SBRT trials

Baumann 57 15 Gy x 3F IA/B 92 60 30%, 79%

Fakiris 70 20-22Gy x 3F IA/B 88 43

Koto 31 15 Gy x 3F 7.5 Gy x 8F

IA/B/IIA T1: 78 T2: 40

72

Ricardi 15 Gy x 3F IA/B 88 73

Timmerman 55 18 Gy x 3F IA/B/IIA 98 56 40%, 62%

Nagata 45 12 Gy x 4F IA/B 98 83

Retrospective SBRT studies

Nyman 45 15 Gy x 3F IA/B 80 55

Onishi 257 4.4-35Gy x 1-4F IA/B 84.2 56.8

Timmerman 70 20-22Gy x 3F IA/B 95 (2 yr) 55 (2yr)

Uematsu 50 7.2 Gy x 10F IA/B 94 (2 yr) 66 (2 yr)

Systematic review: 5-yr OS 40% (17-83%) 5-yr LC 90% (83-95%)

5yr OS RT No treatment

Stage I 15% 14%

Stage II 11% 10%

CHEST 2005; 128:1461–1467

Conventional dose

cIMRT (75.6 Gy/42F) VS hIMRT (72 Gy/30F, 2.4 Gy/F)

Outcome

Failure defined as PSA failure or initiation of salvage therapy. PSA failure was defined using the Phoenix definition of PSA nadir plus 2 ng/mL.

Cumulative incidence of treatment failure Overall survival

Time point hIMRT cIMRT

8-yr 90% 85.2%

10-yr 82.8% 76.1%

Median FU 8.5 years

Time point hIMRT cIMRT

5-yr 8.2% 8.3%

8-yr 10.7% 15.4%

10-yr 10.7% 23.7%

Late Toxicity

Late GI toxicity Late GU toxicity

Time point hIMRT cIMRT

8-yr 12.6% 5%

Time point hIMRT cIMRT

8-yr 15.1% 16.4%

Summary

• Internal margin: ITV (internal target volume) • Interfraction motion and Intrafraction motion

• Motion management

Respiratory motion Pelvic organ

Motion-encompassing methods Respiratory gated techniques Breath-hold techniques Forced shallow-breathing methods Respiration-synchronized techniques

Motion-encompassing methods Gated techniques Tracking technique

Challenges &

Pitfalls

Process map and workflow

J Med Phys. 2012 Oct-Dec; 37(4): 174–182.

Challenge 1: Breath-hold with gating

Arterial phase

Portal phase

Breath-hold

Challenge 2: Abdominal compression with 4D

Arterial phase

4D_End exhale

4D_End inhale

MinIP

Challenge 3: IGRT

CBCT

• Slow CT

• Rotation time: 60 sec

(12-16 beats)

Pitfall 1: 4D-CT

• Pitch

Pitfall 2: DIBH

Pitfall 3: 6D couch