Which monitoring device is best to survey a patient who has received 150 mCi for I-131 therapy?

The portable ionizing chamber is best suited for surveying a patient who has received a high dosage of I-131 therapy, such as the 150 mCi mentioned in the question. This device is designed to accurately measure high levels of radiation and can provide real-time dose rate measurements. It offers high sensitivity and is capable of distinguishing between different types of radiation, making it ideal for assessing the radiation exposure from therapeutic doses of radioactive isotopes.

In this scenario, after I-131 administration, patients can emit significant radiation, particularly in the form of beta particles and gamma rays. The portable ionizing chamber effectively assesses the levels of this radiation and helps ensure patient and public safety by measuring exposure levels accurately.

Other monitoring devices, such as a Geiger-Muller counter, while effective for general surveys, may not offer the specificity or dose rate needed for high-intensity situations like I-131 therapy. Scintillation detectors are also capable but are often more complex and expensive for routine checks like this. Dosimeter badges are designed primarily for personal monitoring over time rather than real-time exposure assessments in high-radiation scenarios.