tomotherapy based image guided imrt

IMPLEMENTATION OF A TOMOTHERAPY BASED IMAGE- GUIDED IMRT PROGRAM THROUGH A FULL SCOPE OF RADIATION THERAPY PRACTICE MODEL

The Ottawa Hospital Regional Cancer CentreOttawa, Ontario

April 2008

The Ottawa Hospital Cancer Centre• Treats approximately 4000 patients annually• 9 conventional linacs (6 Siemens, 3 Elekta Synergy)• 2 TomoTherapy Hi-ART

Implementation of 1st Unit•Installation = 8 days

•Acceptance and commissioning = 2 weeks

•Therapist training = 2 weeks

•1 week without patients

•1 week with patients

•1st patient = 12 September 2005

•Initially 5-6 patients/day

•2nd

Tomo Unit installed Oct/07

•Currently treat 18-20 patients in 8hr day

•25 min bookings

Patients Treated from Sept 05- Current

Site Number of Patients

H&N 128

PELVIS 83

SPINE 22

CNS 24

LUNG 23

ABDOMEN 7

BREAST 23

TOTAL 311

Treatment and Planning

• Started with three therapist planning and delivering treatments– Selected therapists had no previous treatment planning

experience– Training was excellent– Visited three other Tomo sites to gain knowledge and

experience– Planning is an on-going learning experience

Average Planning Time (min)

Currently, average time = 5.5hrs

Task 1st 3m After 9m

Rad Onc. Targets 70 40**

Work @ Planning Station 86 23ROIs 22 6Beamlets 82 73

Optimization 180 120

Time with Onc 33 6

Physics QA 62 60

Total 535 328

**Some targeting takes longer than 40 mins

Planning

• Therapists like treatment/planning model because: – More knowledgeable when registering MVCT– Therapists are able to adjust treatment plans to

reduce/limit some observed side effects– No ‘hand off’ or transfer of information– Able to contribute to prospective protocols

• We now have 7 therapists for 2 units on ‘Team Tomo’

Cord Not Aligned – Need for PRV

Sup. End ok.

Inf. End of cord not perfectly aligned.

Yellow = PRV cord – good thing

PRV= Planning at Risk Volume (ICRU recommendation)

Tomo Group Meetings

• Radiation Oncologists, Therapists and Physics meet weekly to determine:– Who is eligible for treatment (protocols)– Who can benefit most from IMRT treatment (nonprotocol)

• Potential CTVs are reviewed to determine:– Need for bolus and its placement– Immobilization device requirements

• Review treatment plans of patients on treatment

Therapist Perspective

• Therapists feel they are;– Using full-scope-of-practice– Involved at all levels of decision making

• Patient suitability• Targeting• Planning• Treatment• Education• Research

Additional Responsibilities

• Protocol development • Image-guided treatment delivery • Development of policy and procedures• Research

– Testing of new software– Adaptive planning– Publications

RTOG 0521 66/60/56 in 33Added sparing structures used to reduce toxicities

Unknown Primary 66/60/56 in 33Targets are homogeneous

OTT 06-04 In-house Breast + Nodes(IMC) Protocol

OTT 06-04 In-house Breast + Nodes(IMC) Protocol

V20= 6.8%

V5 = 36%

T2N1MO Squamous cell Anus Three PTV’s 60/55/48 in 30 (+chemo)

Rad Onc initially wanted to treat patient in three phases. Tomo team was able to created plan using alternate fractionation.

Whole Brain 3000/10 + Simultaneous Boost to 3 iso 4500/10 in 1plan (25 min)

**London Protocol

CNS – Avoidance Structure in Mid Brain

Therapist created this distribution. Pt is treated supine and has reduced toxicities

StatRT = Scan/Plan/Treat = 40 min

Scan• Place patient on the couch • Scan selected region • Acquire MVCT image set

Plan• Perform 3D contouring at the Operator Station• Set prescription • Optimize the treatment fraction • Evaluate using isodose distribution and dose volume histograms

(DVHs)Treat

• Helical IMRT delivery• Conformal 3D dose distributions • Simple to complex cases

Clinical Pilot

• 25 palliative patients

• Fractionated and single treatments

– Spine

– Abdo

– Lung

– Pelvis

StatRT - Two Targets Rt Hip and Peri-Rectal mass

StatRT - Two Targets Rt Hip and Peri-Rectal mass

Multiple Targets

Simple Targets

Mycosis Fungoides (20/5 to Blue and 15/5 to Red)

Previous TBE 3500/20 (using 6 or 9 MeV electrons) in 2003

Mycosis Fungoides (20/5 to Blue and 15/5 to Red)

Before and After

before

before

after

Our Team

Radiation Therapy– Lynn Montgomery– Kathy Carty– Greg Fox – Jamie Bahm– Bev Macallum– Karen Vanderwerff– Kirsten Keeler– Andre Patry– Sandra Hamilton

Medical Physics–

Jason

Belec–

Brenda Clark–

Lee Gerig–

Miller MacPherson–

Gosia Niedbala–

Balaz

Nyiri–

Janos Szanto

Radiation Oncology–

Rob MacRae–

Laval Grimard–

Shawn Malone–

Libni Eapen –

And a dozen more

Electronics–

Gaetan Belanger–

Georges Gohier–

Najib Nassar

Questions: lmontgomery@ottawahospital.on.ca

Kvanderwerff@ottawahospital.on.ca