Stereotactic Cyberknife based radiotherapy: introduction and possible dosimetric comparisons with other treatment techniques

Stereotactic

Cyberknife based radiotherapy

in Liege

introduction

possible dosimetric comparisons

?

Nicolas Jansen April 2011

• From simple to complex

• From medium dose to ultra high dose

• From large volumes to small volumes

• From unefficient to very efficient ?

• From surgery to radiotherapy ??

• From cheap to expensive ??? (or …)

The pendulum swings …

Acta Oncol. 1995;34(6):861-70. Stereotactic high dose fraction radiation therapy of extracranial tumors using an

accelerator. Clinical experience of the first thirty-one patients.

Blomgren H et al. Karolinska Hospital, Stockholm, Sweden

Int J Radiat Oncol Biol Phys. 2000 Sep 1;48(2):449-57. Megavoltage CT-assisted stereotactic radiosurgery for thoracic tumors: original research in the treatment of thoracic neoplasms.

Nakagawa K et al. University of Tokyo, Tokyo, Japan Rapid

introduction in clinical

practice

In

Belgium ?

Curr Probl Cancer. 2003 Jan-Feb;27(1):60-3.

New potentials of radiotherapy in non-small cell lung cancer: stereotactic therapy and IMRT. Van Houtte P. Radiation Department, Institute Jules Bordet, Brussel

J Vasc Interv Radiol. 2005 Jan;16(1):51-6. Percutaneous placement of marking coils before stereotactic radiation therapy of malignant lung lesions. de Mey J et al.

Department of Radiology, UZ Brussel

Cancer Radiother. 2010 Oct;14(6-7):446-54 Gating and tracking, 4D in thoracic tumours. Verellen D et al. Department of Radiotherapy, UZ Brussel

Int J Radiat Oncol Biol Phys. 2010 Aug 12. Prospective, Risk-Adapted

Strategy of Stereotactic Body Radiotherapy for Early-Stage Non-Small-Cell Lung Cancer: Results of a Phase II Trial. Bral S, et al. Department of

Radiotherapy, UZ Brussel

Example for lung SRS …

• Assessment of the uncertainties in dose delivery of a commercial system for

linac-based stereotactic radiosurgery - Verellen D, et al. - Int J Radiat Oncol Biol Phys. 1999-5 1;44(2):421-33

Are there any quality differences in

stereotactic radiotherapy approaches ?

• Differences based on …

– Experience

– Internal workflow and quality control

– Technical differences in treatment delivery

system

• Beam characteristics • Tracking capabilities • …

What are the different systems for

stereotactic radiotherapy delivery ?

• Stereotactic placement of sources for

prostate brachytherapy

• (Very conformal treatments)

• Classical linac based (Novalis)

• Tomotherapy based systems

• Purpose build stereotactic devices with

inherent 4D capabilities

– Vero

• Comparison of stereotactic approaches

– Ideally : clinical outcome based (long time effort)

• Narrow comparison : between stereotactic systems

• Wider comparison : Stereotactic radiotherapy versus … protontherapy, surgery, targeted systemic therapies, …

– Dosimetric comparison

• Narrow comparison : between stereotactic devices

• Wider comparison : stereotactic systems relative to a more ‘classical approach’ to be able to justify the

Comparing radiotherapy approaches

• Clinical outcome

• Dosimetric

• Time

• Cost

• Availability

• Acceptability

Comparing radiotherapy approaches

• Clinical outcome

• Dosimetric

• Time

• Cost

• Availability

• Acceptability

Dosimetric comparison

• How to compare ?

– For each OAR : different DVH parameters – For the PTV : the coverage, … (indices)

• But cheating is possible

– (Forgetting) margin management – Look only at high dose regions

Dosimetric comparison

• How to compare plan results ?

– DVH comparison

• Curve form

• Key DVH parameters

– DVH indices

– Dose distribution itself

Dosimetric comparison

• How to compare plan results ?

– DVH comparison

• Curve form

• Key DVH parameters

– DVH indices

– Dose distribution itself

Dosimetric comparison

• How to compare plan results ?

– DVH comparison

• Curve form

• Key DVH parameters

– DVH indices

– Dose distribution itself

Dosimetric comparison

• DVH derived parameters

– Validated for stereotatic treatments ? – Are they clinically relevant ?

• Which ones do we want to analyse ?

– Single point constraints/limits

• Vx • Dx

– Mathematically derived parameters

• CI, DHI,

– Tumor response models

• Lyman NTCP model

• Local Radiation Response - Organ Functional Reserve Models

Dosimetric comparison

• DVH derived parameters

– Validated for stereotatic treatments ? – Are they clinically relevant ?

• Which ones do we want to analyse ?

– Single point constraints/limits

• Vx • Dx

– Mathematically derived parameters

• CI, DHI,

– Tumor response models

• Lyman NTCP model

• Local Radiation Response - Organ Functional Reserve Models

DVH parameters

• CI :

– V

/ V

– Conformity index

– A ratio of VOLUMES

– Ideally CI = 1

– RTOG radiosurgery quality guidelines :

• CI = 1.0 to 2.0

• CI = 0.9 to 1.0 or 2.0 to 2.5 : minor deviation • CI < 0.9 or CI > 2.5 : major deviation

DVH parameters

• CI :

– Min isodose surrounding the target / Reference isodose

– Coverage index

– A ratio of DOSES

– Ideally 100%

– RTOG radiosurgery quality guidelines :

• CI > 90% : adequate

• CI 80% to 90% : minor deviation • CI < 80% : major deviation

DVH parameters

• HI :

– Max isodose in the target / Reference isodose

– Homogeneity Index

– A ratio of DOSES

– Ideally HI = 1 ?

– RTOG radiosurgery quality guidelines :

• HI 1.0 to 2.0 : adequate

• HI 2.0 to 2.5 : minor deviation • HI > 2.5 : major deviation

Dosimetric comparison

• Pre-analysis standardisation

– Equal image set used – Identical GTV-CTV

– Identical dose and fractionation

• But …

– Not all systems require the same immobilisation – Different treatment execution errors and different

tracking parameters can induce different … margins

Margins …

• Reflect the imprecisions and errors of the whole

treatment preparation and delivery chain

• GTV to CTV : should be identical

• CTV to PTV : to be re analysed for each technique

• Are a source of … errors

– Unrealistic margins

– Should be adapted to … new imprecisions

• Marker tracking • …

Ablative dose, no ablative results

• If the dose is ablativen why is the LC after the

treatment not 100%

– The staging was incomplete or inaccurate

– The dose is not ablative because of radioresistance

What do we know about comparisons in

stereotactic radiotherapy ?

• First data

– Dosimetric comparison of stereotactic radiosurgery to intensity modulated radiotherapy - Kramer BA, Wazer DE, Engler MJ, Tsai JS, Ling MN - Radiat Oncol Investig. 1998;6(1):18-25.

– Dosimetric comparison of stereotactic body radiotherapy in different respiration

conditions: a modeling study - Kontrisova K, Stock M, Dieckmann K, Bogner J, Pötter R, Georg D - Radiother Oncol. 2006 Oct;81(1):97-104

– Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems - Sharma SD, Kumar S, Dagaonkar SS, Bisht G, Dayanand S, Devi R,

What do we know about comparisons ?

• Not cyberknife related : hot topic last 6 months!

– Cost-Effectiveness Analysis of Stereotactic Body Radiotherapy and Radiofrequency Ablation

for Medically Inoperable, Early-Stage Non-Small Cell Lung Cancer - Sher DJ, Wee JO, Punglia

RS - Int J Radiat Oncol Biol Phys. 2011 Feb 10

– Comparison of stereotactic brachytherapy (125 iodine seeds) with stereotactic radiosurgery

(LINAC) for the treatment of singular cerebral metastases - Ruge MI, Kocher M, Maarouf M,

Hamisch C, Treuer H, Voges J, Sturm V - Strahlenther Onkol. 2011 Jan;187(1):7-14

– Stereotactic radiotherapy for peripheral lung tumors: a comparison of volumetric modulated

arc therapy with 3 other delivery techniques - Ong CL, Verbakel WF, Cuijpers JP, Slotman BJ,

Lagerwaard FJ, Senan S - Radiother Oncol. 2010 Dec;97(3):437-42

– Randomised phase I/II study to evaluate carbon ion radiotherapy versus fractionated

stereotactic radiotherapy in patients with recurrent or progressive gliomas: the CINDERELLA trial - Combs SE, Burkholder I, Edler L, Rieken S, Habermehl D, Jäkel O, Haberer T, Haselmann R,

Unterberg A, Wick W, Debus J - BMC Cancer. 2010 Oct 6;10:533

– Dose-volume comparison of proton radiotherapy and stereotactic body radiotherapy for

non-small-cell lung cancer - Kadoya N, Obata Y, Kato T, Kagiya M, Nakamura T, Tomoda T, Takada

A, Takayama K, Fuwa N - Int J Radiat Oncol Biol Phys. 2011 Mar 15;79(4):1225-31

– Dosimetric comparison of intensity-modulated stereotactic radiotherapy with other

stereotactic techniques for locally recurrent nasopharyngeal carcinoma - Kung SW, Wu VW,

Kam MK, Leung SF, Yu BK, Ngai DY, Wong SC, Chan AT - Int J Radiat Oncol Biol Phys. 2011 Jan 1;79(1):71-9.

What do we know about comparisons ?

• Cyberknife related

– A dosimetric comparison between Gamma Knife and CyberKnife treatment plans for trigeminal neuralgia - Descovich M, Sneed PK, Barbaro NM, McDermott MW, Chuang CF, Barani IJ, Nakamura JL, Lijun M - J Neurosurg. 2010 Dec;113 Suppl:199-206 (University of California, San Francisco)

– A dosimetric comparison of stereotactic body radiation therapy techniques for lung cancer: robotic versus conventional linac-based systems - Ding C, Chang CH, Haslam J, Timmerman R, Solberg T - J Appl Clin Med Phys. 2010 Jun 29;11(3):3223 (University of Texas Southwestern Medical Center, Dallas) – Intracranial radiosurgery in the Netherlands. A planning comparison of available systems with

regard to physical aspects and workload - Schoonbeek A, Monshouwer R, Hanssens P, Raaijmakers E, Nowak P, Marijnissen JP, Lagerwaard FJ, Cuijpers JP, Vonk EJ, van der Maazen RW - Technol Cancer Res Treat. 2010 Jun;9(3):279-90 (Radboud University Nijmegen Medical Centre, Nijmegen)

– Quality of radiosurgery for single brain metastases with respect to treatment technology: a matched-pair analysis - Wowra B, Muacevic A, Tonn JC. - J Neurooncol. 2009 Aug;94(1):69-77 –(European

CyberKnife Center Munich)

– Comparison of advanced irradiation techniques with photons for benign intracranial tumours - Cozzi L, Clivio A, Bauman G, Cora S, Nicolini G, Pellegrini R, Vanetti E, Yartsev S, Fogliata A - Radiother Oncol. 2006 Aug;80(2):268-73 (Oncology Institute of Southern Switzerland, Medical Physics, Bellinzona,

Switzerland )

– Dosimetric comparison of CyberKnife with other radiosurgical modalities for an ellipsoidal target - Yu C, Jozsef G, Apuzzo ML, Petrovich Z - Neurosurgery. 2003 Nov;53(5):1155-62 (University of Southern California, Los Angeles)

A dosimetric comparison between Gamma Knife and CyberKnife treatment plans for trigeminal neuralgia - Descovich M, Sneed PK, Barbaro NM, McDermott

MW, Chuang CF, Barani IJ, Nakamura JL, Lijun M - J Neurosurg. 2010 Dec;113 Suppl:199-206 (University of California, San Francisco)

Discussion : what treatment planning efforts have been done ?

A dosimetric comparison of stereotactic body radiation therapy techniques for lung cancer: robotic versus conventional linac-based systems - Ding C, Chang

CH, Haslam J, Timmerman R, Solberg T - J Appl Clin Med Phys. 2010 Jun 29;11(3):3223 (University of Texas Southwestern Medical Center, Dallas)

• n=8 / common contours / 3x20 Gy

• 4D CT scan → MIP creation

• PTV 3D created, also PTV 4D

A 4D CT scanning is performed. A 3D conformal linac- SBRT plan is designed on ITV and

corresponding PTV 3D.

A deformable registration method is then applied to obtain the 4D cumulative dose distribution.

GTV and PTV 4D are contoured on the 50% phase of 4D CT

images, which corresponds to the maximum exhalation.

The 50% phase of 4D CT images and contour sets of GTV and

PTV 4D are sent to CyberKnife system for Synchrony planning.

CI = conformity index =

the ratio of the tissue volume receiving the prescription isodose or more to the tumor volume

Intracranial radiosurgery in the Netherlands. A planning comparison of available systems with regard to physical aspects and workload - Schoonbeek A, Monshouwer R, Hanssens P, Raaijmakers E, Nowak P, Marijnissen JP, Lagerwaard FJ, Cuijpers JP, Vonk EJ,

van der Maazen RW - Technol Cancer Res Treat. 2010 Jun;9(3):279-90 (Radboud University Nijmegen Medical Centre, Nijmegen)

• 5 systems – CK – Gammaknife – Novalis 3 mm leafs – Tomotherapy – Linac 10 mm leafs

• GTV + 2 mm = PTV (fixed for all systems) • N = 5 patients (skull base tumors)

– 3 size levels

• 3 target volumes

– 0.1 ml : no system can respect the

conformality index (all >3.0)

– 0.5 ml : better for CK, GK

Quality of radiosurgery for single brain metastases with respect to treatment technology: a matched-pair analysis - Wowra B, Muacevic A, Tonn JC. - J

Neurooncol. 2009 Aug;94(1):69-77 –(European CyberKnife Center Munich)

• With a matched-pair analysis we were able to prove that identical quality of clinical results in single brain metastases can be achieved with the GK and the CK. • Furthermore we could show that the radiosurgical

dose can be better tailored to the target with the CK than with the GK.

• This result, a more homogeneous dose distribution, and a lower peripheral dose represent an advantage of the CK in regard of the radiation protection

Comparison of advanced irradiation techniques with photons for benign intracranial tumours - Cozzi L, Clivio A, Bauman G, Cora S, Nicolini G, Pellegrini R, Vanetti E, Yartsev S,

Fogliata A - Radiother Oncol. 2006 Aug;80(2):268-73 (Oncology Institute of Southern Switzerland, Medical Physics, Bellinzona, Switzerland )

AMOA = intensity modulated arc therapy HT = helical thomotherapy

Dosimetric comparison of CyberKnife with other radiosurgical modalities for an ellipsoidal target - Yu C, Jozsef G, Apuzzo ML, Petrovich Z - Neurosurgery.