1. Characteristics of the iba In-Vivo Dosimetry System. Dawn Broadhead Sheffield 9 th October 2010

2. 2 www.qados.co.uk Introduction: The In-Vivo System comprises the following elements:  Hardware – Electrometers  Detectors - Diodes  Support devices – Diode holders / Jigs  Software / Data Management System

3. 3 www.qados.co.uk 3 Electrometer examples  DPD-3  DPD-12  DPD-510

4. 4 www.qados.co.uk Electrometers: DPD-12 – -12 Channels and is installed in the Linac room. -Requires software to drive DPD-3 – - 3 Channels and is installed in Control area -Is both a stand alone and software driven system DPD-510- -Old 10 channel Electrometer – Both stand alone and software driven

5. 5 www.qados.co.uk 5 Detectors  Diodes EDP-5 EDP-10 EDP-15 EDP-20 EDP-HL EDD-2 EDD-5 IDF-1, -3, -5, -thin

6. 6 www.qados.co.uk IBA Ceiling Mounted Holder  Diodes can be drawn out of the holder to the required length  A locking mechanism holds the cable at that length.  Cable retracts gracefully into holder when pulled again

7. 7 www.qados.co.uk 7 Advantages with semiconductors  Small size  High electrical signal (18,000 times higher than ion chambers)  No bias voltage  Robust  No air-pressure dependence  No effects of recombination  Fast response (Life-time of charge-carriers 5 µs)  Real time

8. 8 www.qados.co.uk 8 In vivo diodes - hemispherical build-up 3G InVivo Detectors Build-upColorApplication areaSensitivity decrease meas. at 250 Gy EDP5 3G 5mmBlueTBI Electrons <1% (less than the meas. Accuracy), in 60 Co EDP10 3G 10mmGreen4-8 MV entrance dose few corrections <1% (less than the meas. Accuracy), at 5 MV EDP15 3G 15mmRed6-12 MV entrance dose few corrections <1% (less than the meas. Accuracy), at 6 MV EDP20 3G 20mmYellow8-16 MV entrance dose few corrections 1.2%, at 15 MV

9. 9 www.qados.co.uk 9 In vivo diodes – special design 3G InVivo Detectors Build-upColorApplication areaSensitivity decrease meas. at 250 Gy EDPHL 3G 14mmWhite16-25 MV entrance dose low perturbation 4%, at 21 MV EDD2 3G 2mmGreyEntrance dose low perturbation Exit dose Electrons 60 Co <1% (less than the meas. Accuracy), in 60 Co EDD5 3G 5mmBlackRisk organ monitoring <1% (less than the meas. Accuracy), in 60 Co

10. 10 www.qados.co.uk 10 In vivo diodes – Intracavitary use Intracavitary detectors Application areaDiameter / lengthComment IDF-1 3G Brachytherapy Teletherapy 8mm / 260 mmSensitivity decrease meas. at 250 Gy, <1% IDF-3Brachytherapy8 mm / 260 mmn-type diode IDF-5Brachytherapy8 mm / 260 mmn-type diode IDF-thinBrachytherapy3 mm / 450 mmn-type diode

11. 11 www.qados.co.uk 11 Accessories Detector support Standard Advanced (ceiling) Mobile  Shortens set up time  Easy to identify the correct detector  Increases detector life time Temperated calibration phantom IDF calibration phantom Sterilized rubber sleeves for IDF

12. 12 www.qados.co.uk IBA Floor Mounted Holder The floor Mounted Holder uses a similar system of pulleys and weights, but has them housed in a moveable consol which connects to the electrometer with a long cable. Picture courtesy of Hammersmith Hospital

13. 13 www.qados.co.uk In Vivo Management System The InViDos system offers you:  Complete In Vivo dosimetry application  Measurement and presentation of data  Integration with verification systems  Patient database  Calibration support  Fraction-dose in prescription point  Special features

14. 14 www.qados.co.uk The Invidos Software:  The Invidos software has many levels of usage and workload: Fast and easy for daily use Perform a measurement Add a new patient Medium workload Sensitivity calibration Comprehensive functionality Correction factors Equipment setup Physicist Therapist

15. 15 www.qados.co.uk Sensitivity calibration New patient Correction factors Equipment setup InViDos Daily Weekly Once! Seldom In vivo Measurement Frequently

16. 16 www.qados.co.uk In vivo measurement  Enter patient ID  Position the diode on the patient  Observe dose on screen  Dose automatically saved  nb  If the verification interface is active then all patient demographics and machine set up are transfered automatically – this makes it very simple to use!

17. 17 www.qados.co.uk New patient File/New/Patient  Field Radiation device settings  Detector Measurement positions Enter temperature Enter SSD  Dose Enter expected dose at Diode position Prescription point

18. 18 www.qados.co.uk Equipment setup Tools/Radiation Device Setup  Type Energies Wedges Applicators Tools/Electrometer Setup  Type Tools/Detector Setup  Type  Connected to (em channel)  Temperature dependence

19. 19 www.qados.co.uk Special features  Printing reports  Setting alarm/action levels  Scheduling measurements

20. 20 www.qados.co.uk Special features  Locally or network configuration  Full support to move patients to alternative treatment rooms  Share computer with the Verification system InViDos Patient DB InViDos Equipment DB 1 2 DPD InViDos

21. 21 www.qados.co.uk Patient database  Treatment set-up data  Administrative patient information  Information in each measured point Position, detector, calibration and electrometer Measured and planned dose Action Level Temperature  Measured and planned dose in prescription point

22. 22 www.qados.co.uk QADOS Thank you for your time. Any questions?