CPHON Radiation Therapy in Pediatric Oncology

Question 1

What is the standard SI unit used to measure absorbed radiation dose in radiation therapy?

Accepted Answer

Gray (Gy)

Answer

The Gray (Gy) is the SI unit of absorbed radiation dose, defined as 1 joule of energy absorbed per kilogram of tissue.

Question 2

Which type of radiation therapy delivers radiation from a source placed directly inside or adjacent to the tumor?

Accepted Answer

Brachytherapy

Answer

Brachytherapy places a radioactive source inside or near the tumor, delivering a high local dose while limiting exposure to surrounding healthy tissue.

Question 3

Which pediatric brain tumor most commonly requires craniospinal irradiation as part of its treatment?

Accepted Answer

Medulloblastoma

Answer

Medulloblastoma carries a high risk of leptomeningeal dissemination via cerebrospinal fluid, making craniospinal irradiation a standard component of treatment.

Question 4

What is the primary advantage of proton therapy over conventional photon radiation in pediatric oncology patients?

Accepted Answer

Reduced exit dose and significantly less radiation to healthy surrounding tissues

Answer

Protons deposit maximum energy at the Bragg peak and produce minimal exit dose, dramatically reducing radiation exposure to healthy tissues beyond the tumor—critical in growing children.

Question 5

According to the CTCAE grading scale, which finding characterizes grade 2 radiation dermatitis?

Accepted Answer

Moderate to brisk erythema with patchy moist desquamation in skin folds

Answer

Grade 2 radiation dermatitis is defined by moderate to brisk erythema with patchy moist desquamation, primarily confined to skin folds.

CPHON Exam Practice Test

CPHON Exam Practice Test

CPHON Radiation Therapy in Pediatric Oncology