1. RapidArc in Bergen Britt Nygaard, Harald Valen and Ellen Wasbø
Haukeland University Hospital, Bergen, Norway

2. 2007: 2008: Autumn 2009: 2010: Trilogy with RapidArc option
Scandidos Delta4 QA tool
Aria upgrade: RapidArc on the Trilogy and 23iX
Autumn 2009:
Course in Bellinzona and Zug
Stay-and-learn in Copenhagen
Eclipse AAA configuration
Machine QA and patient QA procedures
2010:
Decisions, decisions.. Which category of patients?
Learning RapidArc doseplanning in Eclipse
1st patient on 14th of June – 2nd on 22nd of November

3. Quality control
Commisioning tests as suggested by Memorial Sloan-Kettering CC and Varian
A picket fence test during RapidArc
7 adjacent fields with varying Dose rate & Gantry speed
4 adjacent fields with varying MLC speed & Gantry speed
Possible to study combined effect of
dose rate and gantry speed
dynamic MLC and variable dose rate
C. C. Ling et. al: Commissioning and Quality Assurance of RapidArc Delivery System. Radiotherapy, Int. J. Radiation Oncology Biol. Phys., Vol. 72, No. 2, pp. 575–581, 2008.

4. Dose rate and Gantry speed variation during RapidArc
MLC speed variation during RapidArc

5. Analyse results Dose rate and Gantry speed variation (”Test2”)
MLC speed variation (”Test3”)

6. Clinac 23EX (2004): T2 & T3 Ttest2: MU/min °/s MU/° Red: 105 4.8 0,364
Drk Green: ,727
Violet: ,091
Blue: ,455
White: ,818
Pink: ,045
Green: ,273
Ttest3:
Rød:
Grønn:
Lilla:
Blå:

7. Trilogy (2007): T2 & T3

8. Clinac 23iX (2005): T2 & T3

9. TrueBeam (2011): T2 & T3

10. Analyse results Dynalog files Tool: ”Analyse Dynalog”
Log planned and actual leaf positions and leaf speed vs. time
Log gantry speed vs. Time
How TrueBeam
Tool: ”Analyse Dynalog”
In-house developed (EW)
Language: IDL

12. Patient QA Delta4 Daily dose correction
Run and measure Verification plan
Pass / Fail criteria
Dose deviation
> 85% within ±3% deviation
Distance to agreement
> 98% with DTA ≤ 3mm
Gamma index 3%, 3mm
> 95% with index ≤ 1

13. 1 arc, 135° to 225°, TrueBeam 6MV photons

15. Clinac 23EX (2004), RapidArc in 2011: Failed T2 & T3 commissioning tests
Patient QA
Dose dev. within ±3%
DTA < 3mm
γ < 1 (3%, 3mm)
PAB
90,7%
100% GB
83,7%
TER
95,8%
99,4%
GDG
85,5%
EKGP
85,9% MS
83,0%

16. More patient QA Independent dose calculation Point check of dose
Control of monitor units

17. Treatment planning, Autumn 2010:
5 years experience with IMRT
head and neck
prostate with and without lymph nodes (LN)
ani (and gyn) with LN
Sarcoma, lymphoma and other
RA configuration and acceptance tests OK
RA installed on 2 Clinacs
Patient start up 17

18. Which patient groups? Increased efficiency for the department
Prostate with LN, 7 splitted fields
Patients unable to keep the supine position for min
Head and neck
Less MU and less risk for secondary cancer
A category that is easy to create acceptable and standardized plans for
Prostate intermediate risk 18

19. Which patient groups? Increased efficiency for the department
Prostate with LN, 7 splitted fields
Patients unable to keep the supine position for min
Head and neck
Less MU and less risk for secondary cancer
A category that is easy to create acceptable and standardized plans for
Prostate intermediate risk 19

20. Prostate intermediate risk, criteria:
Treatment of prostate and seminal vesicles
Equal plan or better than IMRT (PTV and rectum)
We made two plans, one IMRT (backup) and one RA, 1 arc ° (avoid couch slides) for the 10 first patients
PTV 95%-107%, median 100%,
Rectum: max 10ml >60 Gy and less than 50 Gy to half the circumference
Delta4 measurements OK;
Gamma index 3%, 3mm
> 95% with index ≤ 1
Dose deviation
> 85% within ±3% deviation
Dose difference 3%, histogram centered around 0 20

21. 5 fields IMRT: 574 MU (2.15 Gy x 35)
RA: 1 arc ° 494 MU (2.15 Gy x 35) 21 21

22. 5 fields IMRT: 574 MU (2.15 Gy x 35 = 75.25)
RA: 1 arc ° 494 MU (2.15 Gy x 35) 22 22

23. 5 fields IMRT:
RA: 1 arc ° 23

24. IMRT RA 24

25. RA today: (2. 4 Gy sem. ves. and integrated boost 2
RA today: (2.4 Gy sem.ves. and integrated boost 2.7 Gy prostate) x 25 = 67.5 Gy (EQD2= 81 Gy if α/β=1.5)
Today we use 6MVX, more MU (+6%) than with 15MVX but no neutrons.
Ca 620 MU for 2.7 Gy (Calibration 130 MU 10*10 field 10 cm depth equals 1Gy)
We use implanted gold markers and we have got IGRT-couch in the calculation. 25 25

26. 1.9 cm, limit 2.6cm 26 26

27. Measured with Delta4
Gamma: 2mm 2% 27 27

28. Prostate high risk: 2 Gy to the lymph nodes, integrated boost; 2
Prostate high risk: 2 Gy to the lymph nodes, integrated boost; 2.4 Gy sem.ves. and 2.7 Gy prost, fractions
7 field-IMRT
1499 MU (2.7 Gy)
555 MU/Gy
(calibration factor 130MU/Gy)
2 full arc RA
611 MU (2.7 Gy) 28

29. IMRT RA 29

30. IMRT RA 30

31. Dose to rectum 31

32. IMRT 32

33. Future:
We would like to treat our high risk protate with LN with two arcs
Prerequisite: RA plan equal or better than IMRT (PTV and rectum)
This autumn we have been focusing on commissioning TrueBeam..
121 pasienter med RA prost +
1 ca penis med paraaortale lkn og lysker
1 lymfom i buken
1 vesica 33