Acute Toxicity for Acute Toxicity for Prostatectomy Patients receiving Prostatectomy Patients receiving y gy g

Intensity Modulated Radiotherapy Intensity Modulated Radiotherapy

V. Kong, T. Craig, A. Bayley, R. Bristow, C. Catton, P. Chung, M. Gospodarowicz, M. Milosevic, P. Warde, C. Ménard

IntroductionIntroductionIntroductionIntroduction

Radical ProstatectomyyEffective treatment for patients with favorable prognostic factors

Intent of Post-Operative RadiotherapyReduces local recurrence rate for high risk patients

Used as either adjuvant or salvage therapy

V. Kong, PMH Conference

PostPost--Operative RadiotherapyOperative RadiotherapyPostPost Operative RadiotherapyOperative Radiotherapy

Treatment Volume & TechniqueqDefined using bony landmark4 Field Box

V. Kong, PMH Conference

Side effects from RadiotherapySide effects from RadiotherapySide effects from RadiotherapySide effects from Radiotherapy

Gastrointestinal (GI)Gastrointestinal (GI)Proctitis Loose bowel movementLoose bowel movement or diarrhea

Genitourinary (GU)y ( )Urinary incontinenceIncreased frequencyPain/Burning senation

V. Kong, PMH Conference

Advancement of TechnologyAdvancement of TechnologyAdvancement of TechnologyAdvancement of Technology

New consensus guideline for prostate bed g pClinical Target Volume (CTV) definition

Increase volume? -> Increase toxicity?

V. Kong, PMH Conference

The need to changeThe need to changeThe need to changeThe need to change

Treatment techniqueqConformal 4 field box

62.7 Gy

V. Kong, PMH Conference

55.0 Gy

ObjectivesObjectivesObjectivesObjectives

To describe the development of an Intensity p yModulated Radiotherapy (IMRT) technique for the Prostate BedT t th li i l d i t i h t i ti fTo report the clinical dosimetric characteristics of the new techniqueTo report acute GI and GU toxicity outcomesTo report acute GI and GU toxicity outcomesTo compare results with a historical cohort treated by 4 field box technique (4FB)treated by 4 field box technique (4FB)

V. Kong, PMH Conference

MethodMethodMethodMethod

50 patients accrued to prospective trialp p p

V. Kong, PMH Conference

Process FlowchartProcess FlowchartProcess FlowchartProcess Flowchart

Patient Education Sessionat e t ducat o Sess o

CT Simulation

Delineation of Regions of Interest (ROI)

Generation of IMRT Distribution

Treatment

V. Kong, PMH Conference

Process FlowchartProcess FlowchartProcess FlowchartProcess Flowchart

Patient Education Sessionat e t ducat o Sess o

CT Simulation

Delineation of Regions of Interest (ROI)

Generation of IMRT Distribution

Treatment

V. Kong, PMH Conference

CT SimulationCT SimulationCT SimulationCT Simulation

Full bladder and empty rectump yPelvic vacuum immobilization device

V. Kong, PMH Conference

Process FlowchartProcess FlowchartProcess FlowchartProcess Flowchart

Patient Education Sessionat e t ducat o Sess o

CT Simulation

Delineation of Regions of Interest (ROI)

Generation of IMRT Distribution

Treatment

V. Kong, PMH Conference

Clinical Target VolumeClinical Target VolumeClinical Target VolumeClinical Target Volume

Inferior CTV (ICTV) Superior CTV (SCTV)

V. Kong, PMH Conference

Wiltshire et al. IJROBP 2007 69(4); 1090-1099

Planning Target VolumePlanning Target VolumePlanning Target VolumePlanning Target Volume

Planning Target Volume (PTV) Margin (mm)g g ( ) g ( )Online guidance using soft tissue/surgical clip

Chu, 2007

AP SI RLAP SI RL

SCTV 14 13 7

ICTV 10 11 5ICTV 10 11 5

V. Kong, PMH Conference

Organ at Risk (OAR)Organ at Risk (OAR)Organ at Risk (OAR)Organ at Risk (OAR)

Rectal Wall (RW)( )Bladder Wall (BW)Penile Bulb (PB)Penile Bulb (PB)Femur

V. Kong, PMH Conference

Process FlowchartProcess FlowchartProcess FlowchartProcess Flowchart

Patient Education Sessionat e t ducat o Sess o

CT Simulation

Delineation of Regions of Interest (ROI)

Generation of IMRT Distribution

Treatment

V. Kong, PMH Conference

IMRTIMRTIMRT IMRT

7 field step-and-shoot distributionpDose fractionation

66Gy in 33 fractionsy

V. Kong, PMH Conference

IMRTIMRTIMRTIMRT

Treatment planning objectivesp g j1. Avoid irradiating rectum circumferentially to

55 Gy

V. Kong, PMH Conference

IMRTIMRTIMRTIMRT

Posterior Rectal Wall (pRW)(p )

62 7 Gy62.7 Gy55.0 Gy

V. Kong, PMH Conference

IMRTIMRTIMRTIMRT

Treatment planning objectivesp g j1. Avoid irradiating rectum circumferentially to

55 Gy2. PTV D99 ≥ 54 Gy

V. Kong, PMH Conference

IMRTIMRTIMRTIMRT

Treatment planning objectivesp g j1. Avoid irradiating rectum circumferentially to

55 Gy2. PTV D99 ≥ 54 Gy

3. Maximize % of PTV receiving 95% of i ti d Vprescription dose – V95

V. Kong, PMH Conference

Dose ConstraintsDose ConstraintsDose ConstraintsDose Constraints

Organs at Risk Metric Dose (Gy)

Rectal Wall 1 cm3 ≤ 66 0Rectal Wall 1 cm3 ≤ 66.0

Bladder Wall 2 cm3 ≤ 67.3

Penile Bulb 0.5 cm3 ≤ 66.0

Femur 1 cm3 ≤ 55.0

V. Kong, PMH Conference

Monitoring Side EffectMonitoring Side EffectMonitoring Side EffectMonitoring Side Effect

Acute Toxicity Scoringy gCommon Terminology Criteria Adverse Events (CTCAE) v3.0

V. Kong, PMH Conference

V. Kong, PMH Conference

Monitoring Side EffectMonitoring Side EffectMonitoring Side EffectMonitoring Side Effect

Acute Toxicity Scoringy gCommon Terminology Criteria Adverse Events (CTCAE) v3.0

GI GU

Diarrhea FrequencyDiarrhea Frequency

Proctitis Haematuria

CystitisCystitis

Spasm

V. Kong, PMH Conference

Is IMRT better?Is IMRT better?Is IMRT better?Is IMRT better?

Comparison with 4FB techniquep q23 patients with acute toxicity scored using CTCAE v3.0

Dose to Rectal Wall and Bladder Wall Acute GI/GU toxicity

V. Kong, PMH Conference

ResultResultResultResult

Mean PTV V95 = 95.2% (SD = 2.1)95 ( )

16

18

20

10

12

14

16

Number of

4

6

8

of Patients

0

2

90 92 94 96 98 100

PTV V95 (%)

V. Kong, PMH Conference

PTV V95 (%)

ResultResultResultResult64.0

Patient A

60.0

62.0

56.0

58.0PTV D99

(Gy)

R2 = 0.851452.0

54.0

90.0 92.0 94.0 96.0 98.0 100.0

Patient B

Mean PTV D99 = 57.8 Gy (Range: 53.4 – 62.9 Gy)

PTV V95 (%)

V. Kong, PMH Conference

99 y ( g y)

ResultResultResultResultPatient A Patient B

62.7 Gy55.0 Gy

V. Kong, PMH Conference

ResultResultResultResult

Acute GI Toxicity y

Score Diarrhea Proctitis GI0 19 (38%) 17 (34%) 10 (20%)0 19 (38%) 17 (34%) 10 (20%)1 25 (50%) 23 (46%) 27 (54%)2 6 (12%) 13 (20%) 13 (26%)2 6 (12%) 13 (20%) 13 (26%)3 0 0 0

V. Kong, PMH Conference

ResultResultResultResult

Acute GI Toxicity y

Score Diarrhea Proctitis GI0 19 (38%) 17 (34%) 10 (20%)0 19 (38%) 17 (34%) 10 (20%)1 25 (50%) 23 (46%) 27 (54%)2 6 (12%) 13 (20%) 13 (26%)2 6 (12%) 13 (20%) 13 (26%)3 0 0 0

V. Kong, PMH Conference

ResultResultResultResult

Acute GU Toxicityy

Score Frequency Haematuria Cystitis Spasms GU

0 19 (38%) 45 (90%) 39 (78%) 27 (54%) 14 (28%)0 19 (38%) 45 (90%) 39 (78%) 27 (54%) 14 (28%)

1 24 (48%) 5 (10%) 10 (20%) 20 (40%) 28 (56%)

2 5 (10%) 0 1 (2%) 3 (6%) 6 (12%)

3 2 (4%) 0 0 0 2 (4%)

V. Kong, PMH Conference

ResultResultResultResult

Acute GU Toxicityy

Score Frequency Haematuria Cystitis Spasms GU

0 19 (38%) 45 (90%) 39 (78%) 27 (54%) 14 (28%)0 19 (38%) 45 (90%) 39 (78%) 27 (54%) 14 (28%)

1 24 (48%) 5 (10%) 10 (20%) 20 (40%) 28 (56%)

2 5 (10%) 0 1 (2%) 3 (6%) 6 (12%)

3 2 (4%) 0 0 0 2 (4%)

V. Kong, PMH Conference

ResultResultResultResult

Comparison of Dose to Rectal Wallp

1004FBIMRT

60

80

Normalized Volume

IMRT

20

40

Volume (%)

00 1000 2000 3000 4000 5000 6000 7000

Dose (cGy)

V. Kong, PMH Conference

Dose (cGy)

ResultResultResultResult

Comparison of Dose to Bladder Wallp

80

1004FBIMRT

60

80

Normalized Volume

20

40(%)

00 1000 2000 3000 4000 5000 6000 7000

Dose(Gy)

V. Kong, PMH Conference

Dose (Gy)

ResultResultResultResult

Comparison of Acute GI/GU Toxicity Score ≥ 2p y

40

50 IMRT4FB

20

30

40

Number of

Patient

0

10

20(%)

0

GI GU

GI and GU Chi Square value = 5.21 & 9.77, df = 1, p < 0.05

V. Kong, PMH Conference

G a d GU C Squa e a ue 5 & 9 , d , p 0 05

ConclusionConclusionConclusionConclusion

Avoidance of circumferential irradiation of rectum to 55Gy with minimal compromise of PTV coverage is achievable with IMRT

The use of IMRT reduces acute GI/GU toxicity rate when compared with the 4FB technique

Ongoing investigation to determine if improved dosimetry to OARs translates to improved late toxicity and biochemical controltoxicity and biochemical control

V. Kong, PMH Conference

AcknowledgmentAcknowledgmentAcknowledgmentAcknowledgment

Dr. Kirsty WiltshireyDr. William ChuClinical Trial Co-ordinatorsClinical Trial Co ordinators

Debbie TsujiBernadeth Lao

V. Kong, PMH Conference