Practice Test Geeks(CMD) Certified Medical Dosimetrist Practice Test
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Clinical Oncology & Treatment Techniques Flashcards

6 cards from real CMD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Clinical Oncology & Treatment Techniques flashcards as text

  1. Which image-guided radiation therapy (IGRT) technique uses implanted fiducial markers to verify prostate position before each treatment?

    Answer: Kilovoltage (kV) orthogonal imaging with fiducials

    Implanted gold fiducial markers imaged with kV orthogonal or CBCT systems allow daily prostate localization and couch corrections to account for inter-fraction organ motion.

  2. For lung SBRT, the concept of 'dose gradient outside the PTV' is particularly important because:

    Answer: Rapid dose falloff outside the PTV protects surrounding normal lung tissue

    SBRT relies on a steep dose gradient beyond the PTV margin to deliver ablative doses to the tumor while limiting dose to surrounding normal lung, chest wall, and mediastinal structures.

  3. The monitor unit (MU) calculation for a given field must account for which primary factor?

    Answer: Output factor (Sc,p) at the specific field size and depth

    Monitor units are calculated using the output factor (combined collimator and phantom scatter), along with PDD or TMR, SSD correction, and any modifying factors such as wedges or blocks.

  4. Which treatment technique delivers a continuous arc of radiation while simultaneously modulating the MLC positions, dose rate, and gantry speed?

    Answer: Volumetric Modulated Arc Therapy (VMAT)

    VMAT (e.g., RapidArc) simultaneously varies gantry speed, MLC positions, and dose rate during a continuous arc to achieve IMRT-equivalent dose distributions with shorter delivery times.

  5. In cervical cancer brachytherapy, the point A dose prescription refers to a point located:

    Answer: 2 cm superior and 2 cm lateral to the cervical os

    Point A is classically defined as 2 cm superior to the cervical os along the tandem and 2 cm lateral, approximating the paracervical tissue and the crossing of the ureter with the uterine artery.

  6. Which parameter in a treatment plan describes the percentage of the PTV receiving at least 95% of the prescribed dose?

    Answer: V95 (PTV coverage)

    V95 expresses the percentage of PTV volume covered by at least 95% of the prescription dose and is a standard metric for evaluating target coverage in ICRU-based planning.