429 / 1311
Steenbakkers et al Radiother Oncol 2005
Determining GTV: CT
•
Challenges for radiotherapy planning:
–
Atelectasis
–
Effusion
–
Lymph node involvement
•
Use of lung and soft tissue window side-by-
side
–
Lung window for lung interfaces
–
Soft tissue window for mediastinal and hilar interfaces
–
Bone window if infiltration suspected
•
Use of MPR display
•
Lymph nodes remain difficult
Ashamalla et al, IJROBP 2005
Determining GTV: PET/CT
•
Change of GTV from CT alone in 52%
•
Increase of concordance among
observers from 37% to 84%
Black: CT, Purple: PET/CT
Grosu et al Strahlenther Onkol 2005
Determining GTV: PET/CT
•
PET adds essential information to CT
–
Significant consequences on GTV, CTV and PTV
»
Range 21 -100 % of patients
»
Lymph node involvement
»
Differentiation tumor vs. atelectasis
–
Shortcoming: Inflammatory disease
•
Generally recommended for all dose
escalation studies
Lung motion
9.5 ±
4.9
7.2 ±
1.8
4.3 ±
2.4
CC
6.1 ±
3.3
4.3 ±
2.2
2.8 ±
1.3
AP
6.0 ±
2.8
4.3 ±
2.4
3.4 ±
1.6
ML
4.3 ±
2 4
2.8 ±
1.3
AP
Tumor mobility during
shallow breathing [mm]
9.5 ± 4.9
7.2 ± 1.8
4.3 ± 2.4
CC
6.1 ± 3.3
4.3 ± 2.2
2.8 ± 1.3
AP
6.0 ± 2.8
4.3 ± 2.4
3.4 ± 1.6
ML
Lung Tumor Mobility
Plathow et al. 2005
Lung Tumor Mobility after Radiotherapy