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When a radiation dose is fractionated

When treating urinary bladder cancer, which of the following would not be a dose-limiting structure?

Extra Credit: IGRT Module Prior to simulating the patient, which of the following should you do before the patient enters the CT simulation room? 1. Obtain a patient history 2. Check for contraindications for usage of contrast 3. Speak to the radiation oncologist 4. Fabricate immobilization devices 5. Speak with the medical dosimetrist    

You are setting up the patient and the left lateral laser went out while attempting to level the patient.  Which of the following procedures would be the most practical solution?

The oncologist reviews your portal images and determines that the isocenter needs to be shifted. The new isocenter is now 0.3 cm left lateral and 0.5 cm superior. Which of the following statements is incorrect?

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?

Which of the following is not a goal of computed tomography simulation?

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 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

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