RT summary 1.2b
- ICRU = International commission on radiation units and measurements
- For Radiotherapy 2 important reports :
o ICRU 50 : Prescribing, recording and reporting photon beam therapy
o ICRU 62 (the update): Supplement to ICRU 50, which is still valid.
Context:
- Consult CT Treatment planning treatment delivery Patient’s final visit
o Consult: radiation oncologist
o CT: position the patient, add the external body markers
o Patient’s final visit: after this for the radiation oncologist, the follow up treatment
starts.
Treatment goals:
- Radical treatment of malignant (curative treatment)
o Achieve permanent tumor control
o Volumes to be treated: Tumor + expected sub-clinical disease
- Palliative treatment of malignant disease
o Decrease of symptoms
o May include all or only part of tumor (as long as we can guarantee the decrease of
the symptoms)
GTV (Gross tumor volume):
- Gross demonstrates extend and localization of malignant
growth. (the tumor itself)
o Consist of:
Primary tumor
Metastatic lymph nodes
Distant metastasis
! note : if tumor has been removed prior to radiotherapy no GTV
can be find.
- Determination of GTV:
o Clinical:
Inspection
Palpation
Endoscopy
o Imaging techniques:
X-ray
Ultrasound
MRI
PET-CT
o Reason to determine GTV:
, Staging of tumor according to TNM classification
Define area for dose delivery, we should know what to treat
GTV can be used to assess treatment response during or after the treatment.
CTV (clinical target volume):
- The clinical target volume is the margin around the GTV
to include microscopic spread of disease.
o There is always the chance that there are
malignant cells on microscopic levels.
- This volume must be treated thoroughly in order to
achieve the aim of radical therapy.
o So when we perscribe a treatment dose for the
patient we perscribe it for the CTV.
PTV (planning target volume)
- PTV is one of the most important structures.
- Around the CTV we expand a margin, we need that
margin for geometric variations and uncertainties.
o All uncertainties during treatment planning:
In the positions
Sizes
Shapes
Delineation
o All uncertainties during treatment delivery:
Physical uncertainties
Setup errors during positioning
Patient movement
Physical changes in the patient
!! whatever happens we have to guarantee, that our tumor and the CTV is in the high dose area of
our treatment prescription.
Target area:
- ICRU = International commission on radiation units and measurements
- For Radiotherapy 2 important reports :
o ICRU 50 : Prescribing, recording and reporting photon beam therapy
o ICRU 62 (the update): Supplement to ICRU 50, which is still valid.
Context:
- Consult CT Treatment planning treatment delivery Patient’s final visit
o Consult: radiation oncologist
o CT: position the patient, add the external body markers
o Patient’s final visit: after this for the radiation oncologist, the follow up treatment
starts.
Treatment goals:
- Radical treatment of malignant (curative treatment)
o Achieve permanent tumor control
o Volumes to be treated: Tumor + expected sub-clinical disease
- Palliative treatment of malignant disease
o Decrease of symptoms
o May include all or only part of tumor (as long as we can guarantee the decrease of
the symptoms)
GTV (Gross tumor volume):
- Gross demonstrates extend and localization of malignant
growth. (the tumor itself)
o Consist of:
Primary tumor
Metastatic lymph nodes
Distant metastasis
! note : if tumor has been removed prior to radiotherapy no GTV
can be find.
- Determination of GTV:
o Clinical:
Inspection
Palpation
Endoscopy
o Imaging techniques:
X-ray
Ultrasound
MRI
PET-CT
o Reason to determine GTV:
, Staging of tumor according to TNM classification
Define area for dose delivery, we should know what to treat
GTV can be used to assess treatment response during or after the treatment.
CTV (clinical target volume):
- The clinical target volume is the margin around the GTV
to include microscopic spread of disease.
o There is always the chance that there are
malignant cells on microscopic levels.
- This volume must be treated thoroughly in order to
achieve the aim of radical therapy.
o So when we perscribe a treatment dose for the
patient we perscribe it for the CTV.
PTV (planning target volume)
- PTV is one of the most important structures.
- Around the CTV we expand a margin, we need that
margin for geometric variations and uncertainties.
o All uncertainties during treatment planning:
In the positions
Sizes
Shapes
Delineation
o All uncertainties during treatment delivery:
Physical uncertainties
Setup errors during positioning
Patient movement
Physical changes in the patient
!! whatever happens we have to guarantee, that our tumor and the CTV is in the high dose area of
our treatment prescription.
Target area:
