The radioisotope used in bone scan?

VSSC Nursing Officer - 2021

Medical & Surgical Nursing

Easy

Appeared in: VSSC Nursing Officer - 2021

Explanation

Technetium-99m (an isomer of Technetium 99) is the most widely used radioisotope for bone scintigraphy (bone scans).
It is combined with a phosphonate compound (e.g., MDP) that binds to areas of active bone formation and turnover.
Its properties, including a short half-life of 6 hours and emission of gamma rays, are ideal for diagnostic imaging, providing good quality images with a relatively low radiation dose to the patient.
It allows for the detection of various bone pathologies like fractures, infections, and metastases, which appear as 'hot spots' of increased uptake.

Option A: Lithium is a chemical element used as a medication, specifically a mood stabilizer for treating bipolar disorder. It is not a radioisotope and has no application in diagnostic imaging.
Option C: Cobalt, specifically the radioisotope Cobalt-60, is a powerful gamma ray emitter used in radiation therapy (radiotherapy) to treat cancer. It is used for external beam therapy, not for diagnostic scanning.
Option D: Cesium, specifically the radioisotope Cesium-137, is also used in radiation therapy for cancer. It is commonly used in brachytherapy, where the sealed radioactive source is placed inside or near the tumor.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Use of Radioisotopes in Diagnostic Imaging as background academic context rather than a clinical decision trigger.
Nurses are responsible for preparing patients for a bone scan, which includes providing clear instructions about the procedure, the need for hydration, and frequent voiding to ensure patient safety and optimal image quality.
Understanding the different applications of radioactive materials is crucial for nurses to correctly educate patients and distinguish between diagnostic procedures (like a bone scan) and therapeutic procedures (like radiation therapy).
What if? If the patient is breastfeeding, the nurse must provide specific instructions to stop breastfeeding and discard the milk for a designated period (e.g., 24-48 hours, per institutional protocol) after the injection to prevent exposing the infant to radiation.

How to Approach the Question

First, identify the key terms in the question: 'radioisotope' and 'bone scan'. This indicates the question is about a specific diagnostic procedure in nuclear medicine.
This is a factual recall question. Access your knowledge about common medical procedures and the agents used.
Evaluate each option. Think about the primary use of each substance.
Eliminate Lithium, as it is a well-known psychiatric medication, not an imaging agent.
Eliminate Cobalt and Cesium, recalling that they are high-energy sources used for cancer radiation therapy, not diagnostic imaging.
This leaves Technetium 99, which is the most common radioisotope used for a wide variety of diagnostic scans in nuclear medicine, including bone scans. Select this as the correct answer.

Concept Tested & Keywords

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E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart B (pp 240-463 of 478) p. 178-180

E6 Medicine Harrison 22e Part 1 p. 1919-1921