Introduction to Brachytherapy

Presentation Overview

What is Cancer?

Principles of Radiation Oncology

Introduction to Brachytherapy

Typical Treatment Process

Q & A

What is Cancer ?

Cancer is related to:

• Growth

• Differentiation

• Tissue integrity

HYPERPLASIE

Healthycells

DYSPLASIEINTERVASATIE

Blood vessel

organ 1

organ 2

Capillary

TUMOR-cells

CARCINOMAIN SITU

TUMOR-cells INVASIEINTERVASATIETRANSPORTTRANSPORTTRANSPORTAANHECHTINGEXTRAVASATIEEXTRAVASATIEMetastasis

RADIOTHERAPY

SURGERY CHEMOTHERAPY

HORMONE-THERAPY

IMMUNOTHERAPY

Cancer Treatment Options

BRACHYTHERAPY

Principles of Radiation Oncology

Damaging cells with radiation until cell repair is not possible anymore

Repair possibility of “normal” tissue is higher than of tumor cells

Cell Sterilization with Ionizing Radiation

Electron microscope image ofmultiplying cells

Cell Nucleus

cellChromosome

Particle

Why Brachytherapy?

Brachytherapy

Alternative:Surgery

End resultCancer

What is Brachytherapy with Remote Afterloading?

Brachytherapy is Greek for:Brachy = short distance, close-in

Therapy = treatment

Remote Afterloading is:Cancer treatment with radioactive sources controlled from a distance

Why Brachytherapy?

3-Fields External Beam AP-PA External Beam Brachytherapy

Highly conformal

Conformal Brachytherapy

Treat only tumor tissueSpare healthy tissue

Dose is determined by:

Source StrengthExposure TimeSource Position

Brachytherapy: Advantages

Higher local control, due to higher dose to target volume

Less dose to surrounding tissue due to sharp fall-off of radiation dose

Higher treatment dose delivered to the center of the tumor which is more radiation resistant

More conformal treatment due to stepping source technique

Brachytherapy: Disadvantages

Hazard of radiation exposurePotential patient hospitalizationOnly local treatmentSpecial skills and training are neededLicensing and credentialing neededComplete coverage of target volume is essentialSurgical trauma in the case of interstitial techniques

Brachytherapy Delivery Methods

LiquidsPhosphorous (blood disorders)Strontium (bone cancer)Iodine (thyroid)

ImplantsPermanent

(Au-198 or I-125 seeds for prostate)

Temporary (wires or afterloading

techniques)

Manual “hot” loading

Manual Afterloading

Remote Afterloading

Treatments by Type of Loading

Brachytherapy Remote Afterloading Methods

Low Dose RateCesium pellets or Iridium wires, treatment 1-3 days

High Dose RateCobalt-60 pellets, Iridium-192 10 Ci source, treatment in minutes

Pulsed Dose RateIridium-192 1 Ci source, treatment 1-3 days

Afterloader: Low Dose Rate (LDR)

Cesium spheres and Iridium wires

no real optimization possible

long treatment times (days)

well known radiobiological and late effects

1978

Afterloader: High Dose Rate (HDR)

Stepping Iridium-192 source (10 Ci)

200+ applicators for body site specific treatments

Programmable variable source positioning via steps and dwell timesShort treatment times (minutes)

1986 - present

Afterloader: Pulsed Dose Rate (PDR)

stepping Iridium source (0.5 - 2Ci)

no limitation to body sites and curvatures

optimization possible

short radiation times (minutes)

long treatment times (days)

requires less shielding

1986 - present

Brachytherapy Components

Imaging devices

Planning Systems

Body-site Specific Applicators

Remote Afterloaders

Treatments by Location

Intracavitary techniques(i.e. Vaginal, Rectum)

Intraluminal techniques(i.e. Lung)

Interstitial techniques(i.e. Breast, Prostate)

Surface applications(i.e. Skin)

Synergy with Brachytherapy

Brachytherapy – External beam

Brachytherapy – SurgeryPer-operative

Pre-operative (improves surgical outcome)

Brachytherapy – Chemotherapy

Brachytherapy - Hyperthermia

Nucletron is the Solution

microSelectron Digital Afterloader for HDR & PDR Body-site Specific SolutionsPLATO & Oncentra Treatment Planning SystemsTraining LeadershipTechnical SupportLicensing Support Reimbursement SupportService

Question & Answers

History of Radiation Oncology & Brachytherapy