Earliest feature of radiation toxicity is
Correct Answer: Erythema
Description: Ans. a (Erythema). (Ref. Harrison, Principles of Medicine, 15th ed., 2562).RADIATION TOXICITY TO SKIN# Skin reaction can be seen with two weeks of fractionated radiotherapy (RT).# Erythema is the earliest observed feature followed by desquamation (dry/moist).# Chronic reaction can be seen starting at 6-12 months after irradiation.# Atrophic, easily damageable epidermis, hyperpigmentation, thin skin with hair loss also occur.# Rarely malignant change can occur.Educational points:Low-energy ORTHOVOLTAGE beams (150 to 400 kV) scatter when they strike the body, much like light diffuses when it strikes particles in the air resulting in more damage to adjacent normal tissues and less radiation delivered to the tumor.MEGAVOLTAGE radiation (1 MeV) has very low lateral scatter; this produces# a skin-sparing effect,# more homogeneous distribution of the radiation energy, and greater deposit of the energy in the tumor, or target volume.
Category:
Radiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now