Acute Toxicity for Acute Toxicity for Prostatectomy Patients receiving Prostatectomy Patients receiving y y g g I ntensity Modulated Radiotherapy I ntensity Modulated Radiotherapy V . Kong, T. Craig, A. Bayley, R. Bristow, C. Catton, P . Chung, M. Gospodarowicz, M. Milosevic, P . Warde, C. Ménard
I ntroduction I ntroduction I ntroduction I ntroduction � Radical Prostatectomy � Effective treatment for patients with favorable prognostic factors � Intent of Post-Operative Radiotherapy � Reduces local recurrence rate for high risk patients � Used as either adjuvant or salvage therapy V. Kong, PMH Conference
Post Post-Operative Radiotherapy Post Post Operative Radiotherapy Operative Radiotherapy Operative Radiotherapy � Treatment Volume & Technique q � Defined using bony landmark � 4 Field Box V. Kong, PMH Conference
Side effects from Radiotherapy Side effects from Radiotherapy Side effects from Radiotherapy Side effects from Radiotherapy � Gastrointestinal (GI) � Gastrointestinal (GI) � Proctitis � Loose bowel movement � Loose bowel movement or diarrhea � Genitourinary (GU) y ( ) � Urinary incontinence � Increased frequency � Pain/Burning senation V. Kong, PMH Conference
Advancement of Technology Advancement of Technology Advancement of Technology Advancement of Technology � New consensus guideline for prostate bed g p Clinical Target Volume (CTV) definition � Increase volume? -> Increase toxicity? V. Kong, PMH Conference
The need to change The need to change The need to change The need to change � Treatment technique q � Conformal 4 field box 62.7 Gy 55.0 Gy V. Kong, PMH Conference
Objectives Objectives Objectives Objectives � To describe the development of an Intensity p y Modulated Radiotherapy (IMRT) technique for the Prostate Bed � To report the clinical dosimetric characteristics of T t th li i l d i t i h t i ti f the new technique � To report acute GI and GU toxicity outcomes � To report acute GI and GU toxicity outcomes � To compare results with a historical cohort treated by 4 field box technique (4FB) treated by 4 field box technique (4FB) V. Kong, PMH Conference
Method Method Method Method � 50 patients accrued to prospective trial p p p V. Kong, PMH Conference
Process Flowchart Process Flowchart Process Flowchart Process Flowchart Patient Education Session at e t ducat o Sess o CT Simulation Delineation of Regions of Interest (ROI) Generation of IMRT Distribution Treatment V. Kong, PMH Conference
Process Flowchart Process Flowchart Process Flowchart Process Flowchart Patient Education Session at e t ducat o Sess o CT Simulation Delineation of Regions of Interest (ROI) Generation of IMRT Distribution Treatment V. Kong, PMH Conference
CT Simulation CT Simulation CT Simulation CT Simulation � Full bladder and empty rectum p y � Pelvic vacuum immobilization device V. Kong, PMH Conference
Process Flowchart Process Flowchart Process Flowchart Process Flowchart Patient Education Session at 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 Volume Clinical Target Volume Clinical Target Volume Clinical Target Volume Superior CTV (SCTV) Inferior CTV (ICTV) Wiltshire et al. IJROBP 2007 69(4); 1090-1099 V. Kong, PMH Conference
Planning Target Volume Planning Target Volume Planning Target Volume Planning Target Volume � Planning Target Volume (PTV) Margin (mm) g g ( ) g ( ) � Online guidance using soft tissue/surgical clip � Chu, 2007 AP AP SI SI RL RL SCTV 14 13 7 I CTV I CTV 10 10 11 11 5 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 Flowchart Process Flowchart Process Flowchart Process Flowchart Patient Education Session at e t ducat o Sess o CT Simulation Delineation of Regions of Interest (ROI) Generation of IMRT Distribution Treatment V. Kong, PMH Conference
I MRT I MRT I MRT I MRT � 7 field step-and-shoot distribution p � Dose fractionation � 66Gy in 33 fractions y V. Kong, PMH Conference
I MRT I MRT I MRT I MRT � Treatment planning objectives p g j Avoid irradiating rectum circumferentially to 1. 55 Gy V. Kong, PMH Conference
I MRT I MRT I MRT I MRT � Posterior Rectal Wall (pRW) (p ) 62 7 Gy 62.7 Gy 55.0 Gy V. Kong, PMH Conference
I MRT I MRT I MRT I MRT � Treatment planning objectives p g j Avoid irradiating rectum circumferentially to 1. 55 Gy PTV D 99 ≥ 54 Gy 2. V. Kong, PMH Conference
I MRT I MRT I MRT I MRT � Treatment planning objectives p g j Avoid irradiating rectum circumferentially to 1. 55 Gy PTV D 99 ≥ 54 Gy 2. Maximize % of PTV receiving 95% of 3. prescription dose – V 95 i ti d V V. Kong, PMH Conference
Dose Constraints Dose Constraints Dose Constraints Dose Constraints Organs at Risk Metric Dose (Gy) ≤ 66 0 ≤ 66.0 1 cm 3 1 cm 3 Rectal Wall Rectal Wall ≤ 67.3 2 cm 3 Bladder Wall ≤ 66.0 0.5 cm 3 Penile Bulb ≤ 55.0 1 cm 3 Femur V. Kong, PMH Conference
Monitoring Side Effect Monitoring Side Effect Monitoring Side Effect Monitoring Side Effect � Acute Toxicity Scoring y g � Common Terminology Criteria Adverse Events (CTCAE) v3.0 V. Kong, PMH Conference
V. Kong, PMH Conference
Monitoring Side Effect Monitoring Side Effect Monitoring Side Effect Monitoring Side Effect � Acute Toxicity Scoring y g � Common Terminology Criteria Adverse Events (CTCAE) v3.0 GI GU Diarrhea Diarrhea Frequency Frequency Proctitis Haematuria Cystitis Cystitis Spasm V. Kong, PMH Conference
I s I MRT better? I s I MRT better? I s I MRT better? I s I MRT better? � Comparison with 4FB technique p q � 23 patients with acute toxicity scored using CTCAE v3.0 � Dose to Rectal Wall and Bladder Wall � Acute GI/GU toxicity V. Kong, PMH Conference
Result Result Result Result � Mean PTV V 95 = 95.2% (SD = 2.1) ( ) 95 20 18 16 16 14 12 Number of of 10 Patients 8 6 4 2 0 90 92 94 96 98 100 PTV V95 (% ) PTV V95 (% ) V. Kong, PMH Conference
Result Result Result Result 64.0 Patient A 62.0 60.0 PTV D99 58.0 (Gy) 56.0 54.0 2 = 0.8514 R Patient B 52.0 90.0 92.0 94.0 96.0 98.0 100.0 PTV V95 (%) Mean PTV D 99 = 57.8 Gy (Range: 53.4 – 62.9 Gy) y ( g y) 99 V. Kong, PMH Conference
62.7 Gy 55.0 Gy Patient B Patient A Result Result Result Result V. Kong, PMH Conference
Result Result Result Result � Acute GI Toxicity y Score Diarrhea Proctitis GI 0 0 19 (38%) 19 (38%) 17 (34%) 17 (34%) 10 (20%) 10 (20%) 1 25 (50%) 23 (46%) 27 (54%) 2 2 6 (12%) 6 (12%) 13 (20%) 13 (20%) 13 (26%) 13 (26%) 3 0 0 0 V. Kong, PMH Conference
Result Result Result Result � Acute GI Toxicity y Score Diarrhea Proctitis GI 0 0 19 (38%) 19 (38%) 17 (34%) 17 (34%) 10 (20%) 10 (20%) 1 25 (50%) 23 (46%) 27 (54%) 2 2 6 (12%) 6 (12%) 13 (20%) 13 (20%) 13 (26%) 13 (26%) 3 0 0 0 V. Kong, PMH Conference
Result Result Result Result � Acute GU Toxicity Score Frequency Haematuria Cystitis Spasms GU 0 0 19 (38%) 19 (38%) 45 (90%) 45 (90%) 39 (78%) 39 (78%) 27 (54%) 27 (54%) 14 (28%) 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
Result Result Result Result � Acute GU Toxicity Score Frequency Haematuria Cystitis Spasms GU 0 0 19 (38%) 19 (38%) 45 (90%) 45 (90%) 39 (78%) 39 (78%) 27 (54%) 27 (54%) 14 (28%) 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
Result Result Result Result � Comparison of Dose to Rectal Wall p 100 4F B IMR IMR T T 80 60 N ormalized V V olume olume (%) 40 20 0 0 1000 2000 3000 4000 5000 6000 7000 D D ose (cG ose (cG y) y) V. Kong, PMH Conference
Result Result Result Result � Comparison of Dose to Bladder Wall p 100 4F B IMR T 80 80 60 N ormalized V olume (%) 40 20 0 0 1000 2000 3000 4000 5000 6000 7000 Dose (G Dose (G y) y) V. Kong, PMH Conference
Result Result Result Result � Comparison of Acute GI/GU Toxicity Score ≥ 2 p y 50 IM R T 4F B 40 40 N umber 30 of P atient 20 20 (%) 10 0 0 G I G U GI and GU Chi Square value = 5.21 & 9.77, df = 1, p < 0.05 G a d GU C Squa e a ue 5 & 9 , d , p 0 05 V. Kong, PMH Conference
Conclusion Conclusion Conclusion Conclusion � 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 control toxicity and biochemical control V. Kong, PMH Conference
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