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Imaging in the guidance of BT cervical cancer Workshop on GYN IGABT Alina Sturdza Umesh Mahanshety Nicole Nesvacil Maximilian Schmid
Imaging in the guidance of BT cervical cancer
Workshop on GYN IGABT
Alina Sturdza Umesh Mahanshety
Nicole Nesvacil Maximilian Schmid
Outline
• MR delineation • CT delineation • US use in IGBT for cervical cancer • Modalities for improving target and OAR
delineation • Tips for contouring and treatment planning
in the absence of MRI for each BT application
Image guided adaptive brachytherapy (IGABT)
• Individualized: Personalized medicine
• It is adapted to the tumour size at BT, after concurrent EBRT
• Allows dose escalation while sparing the organs at risk
This house believes in MRI at
each application
MRI is the gold standard imaging modality for LACC
Tumor / Target at different points in time • Signs for judgement of tumor at time of
diagnosis • Signs for judgement of tumor / target at time
of brachytherapy (signs of regression and persistance)
Tumor Regression
Workshop on GYN IGBT CT and MR Imaging
Signs for judgement of tumor at time of diagnosis (GTVD)
vaginal invasion
invasion into the parametria
corpus invasion
High signal intensity tumor mass
necrosis GTVD
Signs for judgement of tumor/target at time of brachytherapy (regression - persistance)
IJROBP 2006
Fluid surrounding the cervical canal
Low signal intensity Cervical stroma
measurable tumor mass grey zones in the parametria
HR-CTV
61,0
7,99,010,516,3
0
10
20
30
40
50
60
70
prior to therapy 1. brachytherapy 2. brachytherapy 3. brachytherapy 4. brachytherapy
Abs
olut
e V
ol (c
m³)
Strahlenther Onkol 2009, 5
Quantitative tumor regression EBRT: tumor regression 75% Brachytherapy: tumor regression 10%
EBRT
BT
easy to predict
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
Workshop on GYN IGBT CT and MR Imaging
Comparison between imaging modalities EXAMPLE
axial sagittal coronal
Grey zone Gross tumour
Cervix
Target / Patho-anatomical structures / GTV, HR-CTV contouring on MRI
residual tissue =grey zones
Tumour mass
Workshop on GYN IGBT CT and MR Imaging
HR-CTV
Rectum
Bladder
CTMR
Viswanathan et al. IJROBP 2007
parametrial space
Dimopoulos et al. IJROBP 2006
patho-anatomical structures CT/MRI
parametrial space
nodal structures? Soft tissue?
Workshop on GYN IGBT CT and MR Imaging
Organs at Risk – MRI High resolution multiplanar capability
Workshop on GYN IGBT CT and MR Imaging
HR-CTV
Rectum
Bladder
CTMR
Viswanathan et al. IJROBP 2007
NEEDLES
Applicator MRI /CT
TANDEM
Workshop on GYN IGBT CT and MR Imaging
excellent depiction poor quality
improvement for needles / loss of soft tissue depiction quality
proton weighted
T2 - weighted T2 - weighted
Applicator MRI
Workshop on GYN IGBT CT and MR Imaging
Workshop on GYN IGBT CT and MR Imaging
uterine border and pre-vesical space not visible
uterine border and pre-vesical space visible
Multiplanar Imaging CT / only with reconstruction (improvement with specific protocols and modern scanners)
Workshop on GYN IGBT CT and MR Imaging
Lateral uterine/tumour border not visible Lateral uterine/tumour border visible
Multiplanar Imaging CT / only with reconstruction (improvement with specific protocols and modern scanners)
B
FR
B
RS
FF
GP
RB
S
at diagnosis without vaginal
marking
at diagnosis with vaginal
marking at brachytherapy with specific protocol
IJROBP 2006
Improvement with specific protocol
Workshop on GYN IGBT CT and MR Imaging
PLANE COVERAGE-BORDERS
T2 axial discus L5 inferior border of symphysis pubis
T2 sagittal pelvic wall (obturator muscle) pelvic wall (obturator muscle) T2 frontal or frontal oblique
entire uterus - cervix - vagina - tumor
Axial Sagittal Frontal
Improvement with specific protocol
Workshop on GYN IGBT CT and MR Imaging
Slice orientation parallel/orthogonal to applicator axis
Paracoronal orientation
Paratransverse orientation
Parasagittal orientation
GEC-ESTRO HANDBOOK OF BRACHYTHERAPY
This house believes in MRI at
each application, But also in our good old
finger
/ / dd/mm/yy
Signature
w = __ _ cm h = __ _ cm t = __ _ cm
Vagina Involvement = _ _ cm
w
Infiltrative Exophytic
Cervix
Vagina
Parametria
Rectum or
Bladder
Clinical Drawing Patient: At Diagnosis
w Infiltrative Exophytic
Cervix
Vagina
Parametria
Rectum or
Bladder
Tumour size:
Width: 10 cm
Thickness: - cm
Height: - cm
Vaginal inv.: 5 cm
Clinical drawings at diagnosis
MRI findings
Before BT
Diagnosis
