The Real Time Image Guided HDR Brachytherapy for Prostate ...
Transcript of The Real Time Image Guided HDR Brachytherapy for Prostate ...
The Real Time Image Guided HDR Brachytherapy for Prostate Cancer.
Treatment Planning
Bashar Al-Qaisieh
Treatment Planning Objectives:
Delivery of prescription dose to target volume and minimise dose to nearby
normal tissues
Prostate HDR Treatment Planning Involves:
• Pre-treatment QA:- equipment functionality and connectivity
• Patient setup:- measurement of US probe and template position with respect to patient
• Needle Insertion:- optimal position
• Contouring:- position of applicators with respect to PTV and OAR
• Dosimetry Planning:- needle reconstruction- source activation- optimisation
Patient Setup
• Position of the US probe in the stepper unit
• Position of template with respect to the US probe
• Position of anatomy with respect to the template and US probe
“Virtual”, “Live” & “Post” Operation Functions
“Virtual” Image Capture- Set Base
“Virtual” Image Capture
“Virtual” Contouring
• Option 1:- Contour Prostate, Urethra, Rectum
- Utilise to produce a “virtual” plan- Utilise at later stages after needle insertion
• Option 2:- Calculate volume estimate from H,W,L measurement (SJIO)
“Virtual” Contouring- Option 1
“Virtual” Contouring- Option 2HWL Volume Estimate
0
10
20
30
40
50
15 20 25 30 35 40 45
Virtual height (mm)
Live
hei
ght (
mm
)
0
10
20
30
40
50
60
70
25 30 35 40 45 50 55
Virtual width (mm)Li
ve w
idth
(m
m)
Regression line
Recorded live width
95%
90%
85%
80%
0
10
20
30
40
50
60
70
80
20 25 30 35 40 45 50 55 60
Virtual length (mm)
Live
len
gth
(mm
)
Regression line
Recorded live length
95%
90%
85%
80%
“Virtual” Contouring- Option 2
“Virtual” Needle Insertion
• Option 1:- Forward
- Manual and Geometric- SJIO
• Option 2:- Inverse
- HIPO
“Virtual” Needle Insertion-Option 1:Forward
“Virtual” Needle Insertion-Option 1:Forward SJIO
• Reference transverse plane for peripheral needles
• Base and Apex for middle needles
“Virtual” Needle Insertion-Option 1:Forward SJIO
“Virtual” Needle Insertion-Option 1:Forward SJIO
• All needles inserted to same depth of at least 1.0cm beyond the base to account for needle dead end for metal needle 1 cm
“Virtual” Needle Insertion-Option 2:HIPO
“Virtual” Needle Insertion-Option 2:HIPO
“Live” Image Capture
• All needles pushed to at least 1.0 cm deep from the base.
• Needles Locked to the template.
• Take final base measurement
“Live” Needle Tip Tracking
• All needle tips are updated at the same depth (base). Convert needles from “V” to “L”
“Live” Needle Tip Tracking
“Live” Image Capture
“Live” Contouring Guidance
• Update “Virtual”contours to match “Live” image set
• Prostate dimension pre needle insertion
• Record of needle position with respect to the prostate as a surrogate
“Live” Contouring and PTV Margins
“Live” Contouring
Needles “Live” Tracking
“Live” Source Activation
Planning Aims and Optimisation Options
• Prostate:– 15Gy=100% isodose– V100%>95%– V150%<45%– V200%<15%– D90>100%
• PTV:– V100%>95%
• Rectum:– D2cc<11.8Gy– V100%=0.0cc
• Urethra:– D10%<17.5Gy– D0.1cc<17.5Gy
Morton et al 2009, GEC-ESTRO 2013
Inverse Optimisation-DVHO
TG 43 Dose Calculation
0.5 1.0 1.5 2.0 2.5 3.00123456789
10
r
Dep
th D
ose
Distance (cm)
Inverse Optimisation-DVHO
DVH output
Good Job…well done!!!
• Oncologist check• Approve plan• Print and transfer to treatment machine• Handover to physics to independent check• Handover to radiographers• Have a cup of coffee!!
Timing According to Individual Planners
Planner (no cases) Time from probe in to patient
treated Needle
insertion Needle
reconstruction Planning
A (4) 02:22 00:24 00:14 00:10
B (4) 02:54 00:28 00:29 00:13
C (2) 02:54 00:38 00:16 00:24
D (7) 02:53 00:25 00:16 00:15
E (3) 02:52 00:36 00:21 00:14
Data from 20 implants- 2012
Thank You