CMD CMD Clinical Oncology & Disease Sites 2

Question 1

In cervical cancer brachytherapy combined with EBRT, what dose fractionation is commonly used for the EBRT component?

Accepted Answer

45–50 Gy in 25 fractions to the pelvis

Answer

Standard pelvic EBRT for cervical cancer is 45–50 Gy in 25 fractions (1.8 Gy/fraction), typically combined with concurrent cisplatin chemotherapy and intracavitary brachytherapy.

Question 2

What treatment technique is commonly used for whole-brain radiation to reduce dose to the lens of the eye?

Accepted Answer

Applying a lens block or cerrobend shield

Answer

Custom cerrobend blocks or multi-leaf collimator-based shielding are used to block the lens during WBRT, reducing cataract risk from lens doses.

Question 3

Which staging system is most commonly used for lung cancer to define target volumes in radiation therapy planning?

Accepted Answer

AJCC TNM staging

Answer

The AJCC TNM (Tumor, Node, Metastasis) staging system defines primary tumor extent, nodal involvement, and metastatic status, directly informing target volume delineation for lung cancer.

Question 4

In stereotactic body radiation therapy (SBRT) for early-stage lung cancer, what is a commonly used fractionation regimen?

Accepted Answer

54 Gy in 3 fractions (18 Gy × 3)

Answer

54 Gy in 3 fractions (or 48–60 Gy in 3–5 fractions) is a standard SBRT regimen for peripheral early-stage NSCLC, achieving high local control rates comparable to surgery.

Question 5

What is the most common beam arrangement for treating a right-sided breast cancer with standard tangential fields?

Accepted Answer

Medial and lateral tangents to minimize lung dose

Answer

Medial and lateral tangential fields bracket the breast tissue while minimizing the volume of lung and heart in the treatment field, particularly important for left-sided tumors.

(CMD) Certified Medical Dosimetrist Practice Test

(CMD) Certified Medical Dosimetrist Practice Test

CMD CMD Clinical Oncology & Disease Sites 2