Find the PDD at 19 Cm of an 18-MV Beam

question 13

Multiple Choice

Find the PDD at 19 cm of an 18-MV beam of radiation that has a 12 × 12 cm treatment field.

• A) 56%
• B) 55.6%
• C) 53.7%
• D) 51.7%

---

Definitions:

Metric System

A decimal system of measurement based on the meter, liter, and gram as units of length, volume, and weight or mass, respectively.

Basic Units

The simplest measure of quantity in physics and other sciences, forming the foundation for more complex measurements.

Prefixes

Sets of letters placed before a word to modify its meaning, such as "un-", "pre-", and "post-".

Mixed Fraction

A mathematical expression combining a whole number and a fraction, used to represent quantities greater than one.