1. Radiotherapy
Goal
Maximum dose to Tumor
minimum dose to critical
normal tissues

2. Conventional Portal for T3 Supraglottic
Cancer

3. 3D Conformal Radiotherapy/IMRT
Process
• 3D CRT (developed in early 1990s)/IMRT (late
90s)
• A CT data set of the ROI of the patient is obtained
• Images Transferred to the contouring workstation
(target volumes delineated along with OARs, dose
prescription given)
• Images transferred to TPS (Treatment planning)
• Plan evaluation, Plan Approval, Plan
implementation (sent to treatment unit)

4. IMRT
(Intensity Modulated Radiotherapy)
• Advanced form of 3DCRT
• High Degree of conformity and
sparing of critical structures

6. CRT VS IMRT 8
Conformal: can’t avoid
some level of doses to the
normal tissues
IMRT: sculpt the doses
(isodoses) to the tumor,
avoiding the normal
tissues.

8. IGRT
(Image Guided Radio Therapy)
• Verification of Treatment Set up
with Image Guidance
DRR from TPS is Matched with Treatment Port Film
(From EPID). Any set-up errors are corrected before
Start of Treatment
Planning CT scan is matched with Cone Beam CT scan
generated on the machine (Auto-corrected)

10. • u

14. THANK YOU