Delivery of Radiation therapy has undergone a paradigm shift with the latest technologies. Now with these techniques we can limit daily variation of dose delivery by use of these technology.

2. Dr Suman Das
MD, FUICC (USA)
Consultant Radiation and Clinical Oncologist
Queens NRI Hospital Vizag

3.  Introduction
 Queens NRI Hospital Dept. of Oncology
 CBCT work flow (In our institute)
 View the case

4.  CBCT was first adapted for potential clinical use in
1982 at the Mayo Clinic Biodynamics Research
Laboratory.1
 Initial interest focused primarily on applications in
angiography
 Exploration of CBCT technologies for use in radiation
therapy guidance began in 1992.
 Integration of the first CBCT imaging system into the
gantry of a linear accelerator in 1999.
http://www.ajnr.org/content/30/7/1285.long#ref-4

5.  With CBCT, a full CT scan of the
patient on the treatment couch is
obtained immediately before
radiation delivery
 with the CT scan taken and
reconstructed in less than 2 minutes.
 The CT scan can then be automatically
registered to the CT taken earlier for
treatment planning to facilitate precise
repositioning of the patient to the
treatment machine isocenter.

6. AIM
 Higher doses to PTV and lower doses to normal tissue.
 With the resulting steep dose gradients, motion
management becomes an even more critical part of the
process.

8. Movements During Radiation
Therapy
 Interfractional motion
 Change in patient position between treatment session.
 Patient setup changes
 Patient anatomy changes (tumor shrinking, organ fill status)
 Intrafractional motion
 Change in patient position during a treatment session.
 Breathing
 Gas passing
 Uncooperative patient

9. Role of CBCT
 Reduce interfractional motion
 Patient position adjustment
 No-go condition identification
 Assesses 3D patient status
 Tumor evaluation
 Adaptive planning

10. CBCT imaging components
 KV source and kV imaging panel at 90º to treatment
line used for three imaging modes: planar, fluoro,
CBCT mounted on arms that are motorized to
varying degrees.
 CBCT is 3D aligned with reference image / planning
CT
 various tools: contours, ROIs, color overlay shifts
necessary to align image sets correspond to couch
shifts
 correct patient setup translations and/or rotations
CBCT -data preparation

12. Queens NRI Hospital Vizag
 Clinac IX Liniear accelerator with OBI
 HDR Brachytherapy : Gammamed Plus
 CT based Planning
 Eclipse 10 with CT/MRI/PET registrations
 1062 patients treated
 Every month 70 new patients registered for
radiation
 Daily work load Avg 90 Patients

15. CBCT workflow Queens NRI
Hospital

46.  28yr female
 C/O Hemoptysis for 3 month
 Dyspnea for 15days
 4/4/13: X Ray Chest:
Homogenously opaque Lt
Hemithorax with elevated lt
hemidiaphragm and shift of
mediastinum to lt s/o
collapse or fibrosis of left
lung.

47.  4/4/13: CT Chest: 3.5 x
2.4cm sized
hypoattenuating area
seen towards left main
bronchus completely
obstructing the left
main bronchus.

48.  11/4/13: PET CT : Well defined
homogenously enhancing
hypodense soft tissue encasing
and completely occluding the left
main bronchus. Complete
atelectasis of ;left lung lesion
extending to right side causing
narrowing rt main bronchus.
6.7cm x 3.0cmx5cm.
 30/4/13: HPE: Adenoid cystic
carcinoma of Bronchus.

49. PET CT fusion and volume deliniation

50. Radiation Planning phase 1

53. Ca Cervix Rapid Arc

54. Ca Prostate

55. Ca Tongue