For most pediatric cancer patients under 7 years of age, current standard radiotherapy practice involves the use of anesthesia or sedation at each fraction to ensure that the patient remains still during the treatment. A child may receive up to 30 episodes of anesthesia in succession. This also means that, for the 6-week duration of radiotherapy, a child may never fully return to his/her baseline activity. More importantly, the excessive use of anesthesia introduces many risks and side effects that, combined with chemotherapy, and cancer itself, can greatly reduce the overall treatment experience for the children and their families~In the two years, the investigators have been actively developing technologies to facilitate a novel pediatric radiotherapy, which called Pediatric Radiation Oncology with Movie Induced Sedation Effect (PROMISE). The main idea of PROMISE is that pediatric patient will watch age-proper movie during radiation treatment. The motion of pediatric patient will continually be monitored by an AlignRT system (VisionRT LTD, UK). Both movie and radiation beam will be paused if the motion of pediatric patient is beyond positioning accuracy threshold. Movie and beam will be resumed if pediatric patient is positioning with in tolerance.~In this study, the investigators will use the developed PROMISE software and hardware platform to evaluate the feasibility of non-sedated radiotherapy treatment.~The investigator will use radio to mimic radiation beam delivery and gantry motion to mimic radiation device rotation. Pediatric patient will watch an age-appropriate movie of his/her choice. AlignRT (VisionRT LTD, UK) imaging system will be used to monitor the motion of the patient. If the motion exceeds any pre-defined positioning thresholds the sound mimic treatment beam noise will be held off and the movie will be paused.~If the patient reverts to treatment position within a pre-defined temporal threshold (1 minute), the simulated treatment will be resumed with a continuing movie.~If the patient cannot revert to the treatment position within a pre-defined time threshold/or the movement is beyond any pre-defined re-alignment threshold value the radiation beam and the movie will be turned off, the patient will be readjusted and the treatment will resume.~In any study case, the simulated PROMISE treatment will be ceased if therapists have to re-position the patient more than three times.~The simulated PROMISE treatment will be repeated in three times in three different days.
Pediatric patient will watch age-proper movie during radiation treatment. The motion of pedi-patient will continually be monitored by an AlignRT system (VisionRT LTD, UK).