A female patient has been diagnosed with pancreatic cancer a…

A female patient has been diagnosed with pancreatic cancer and the oncologist’s prescription has the patient treated with AP, RT and LT lateral fields on the Varian 21EX. The anterior treatment area has a 2.5cm superior shift from the leveling marks. The patient is to be treated to a depth of 11.25cm from the anterior and has a lateral separation of 35.6cm and an AP separation of 21.3cm. The AP field size is 13.5cm x 16.5cm and the lateral field sizes are 8.5cm x 16.5cm. What is the AP SSD?

The patient has a metastatic brain tumor.  The oncologist or…

The patient has a metastatic brain tumor.  The oncologist orders parallel opposed lateral fields of the whole brain to be treated midline on the Varian 21EX with a calibrated isocenter of 100 cm. The field size is 21.25 cm x 15.75 cm and the collimator is rotated 28 degrees counter clockwise for the left lateral to avoid treatment to the eyes. The patient’s separation is 16.5 cm. From the following list,  put the procedures in order to complete the patient’s treatment. 1. Rotate gantry → Right Lateral (91.75cm) →rotate collimator clockwise 28 degrees2. Set field size and collimator angle3. Level → Isocenter → Read SSD (91.75cm Left Lateral) and treat4. Return gantry and collimator to 0 degrees5. Read SSD and treat

Extra Credit IGRT Module: Which of the following is useful f…

Extra Credit IGRT Module: Which of the following is useful for proper pelvic alignment for an effective treatment set-up on the linear accelerator? 1. Fiducial markers 2. Vertebral bodies 3. Iliac crest, sacrum, femoral heads 4. Bladder and rectum 5. Ileum 6. Check rotation