Positron Diagnostics: How We Keep Your Radiation Dose as Low as Reasonably Achievable (ALARA)
In nuclear medicine and radiation protection, there is a principle that underpins every decision we make at Positron Diagnostics, from how we design our scan protocols to how our staff handle radioactive materials. It is called ALARA: As Low As Reasonably Achievable. It sounds simple, but it represents a comprehensive philosophy of responsible radiation use. Here is what it means in practice.
What Does ALARA Actually Mean?
ALARA is not about minimising radiation at all costs, as that would mean not scanning patients at all. Rather, it means that every unnecessary unit of radiation should be eliminated, while every necessary unit is fully justified by clinical benefit. The goal is the best possible diagnostic result, at the lowest possible dose, using the most appropriate technology.
ALARA is embedded in European radiation protection law (EURATOM Directive 2013/59) and forms the basis of all nuclear medicine practice guidelines issued by the EANM and the IAEA.
The Three Pillars of Radiation Protection
Classical radiation protection is built on three physical principles that reduce dose to patients, staff, and the public:
•Time: The less time spent in proximity to a radiation source, the lower the dose. At Positron Diagnostics, our closed system automated vial dose dispenser, minimises the time our staff spend handling radioactive material.
•Distance: Radiation intensity decreases with the square of distance. Doubling the distance reduces the dose fourfold (ie. 2m distance = 1/4 radiation exposure). Our facility layout is all engineered to keep staff at safe distances from radioactive materials during preparation and transport.
•Shielding: Physical barriers absorb radiation before it reaches people. Our whole radiopharmaceutical production line is lead-shielded. All radioactive syringes are transported in lead pots. Every room has lead walls and doors. Every layer of shielding is designed to reduce exposure to background levels outside the work area.
How ALARA Applies to Patient Dose
For patients, ALARA means that your radiotracer dose is not a standard number, bu it is a calculation:
•Body weight: Your dose is calculated based on your body weight. A lighter patient receives a lower activity, just enough to produce a diagnostically useful image.
•Scanner sensitivity: Our Discovery IQ Gen 2 PET/CT scan, is a high-sensitivity system. Its advanced detector technology means less radioactive doses are needed to produce an image of equivalent or superior quality compared to older scanners. Better technology directly translates to lower patient doses.
•Clinical indication: The scan protocol is tailored to answer the specific clinical question. A focused brain scan uses a different protocol from a full oncology staging scan and each is optimised for its purpose.
•Regular protocol review: Our medical physics team reviews and benchmarks dose protocols against the latest international diagnostic reference levels (DRLs) the agreed benchmarks for what constitutes good practice.
How ALARA Applies to Our Staff
Our team works with radioactive materials every working day which makes ALARA guidelines particularly important for their long-term protection:
•Personal dosimetry: Every staff member working with radiation wears a dosimetry badge that measures their personal exposure. Results are reviewed monthly and reported annually to the Cyprus Atomic Energy Authority
•Occupational dose limits: European law limits radiation workers to 20 mSv (millisievert, a unit used to measure the biological effect of ionizing radiation on human tissue) per year (averaged over five years). Our staff consistently remain well below this limit a direct result of good facility design and ALARA practice.
•Training and competency: All staff working with radioactive materials hold relevant qualifications and receive ongoing radiation protection training.
Why This Matters to You as a Patient
When you come to Positron Diagnostics for a PET/CT scan, you can be confident that:
•Your dose has been individually calculated based on your body weight
•The scan has been clinically justified by your referring physician
•Our equipment is optimised to deliver the lowest dose consistently with an excellent result
•Our facility, staff, and procedures are regulated, inspected, and continuously reviewed
PET/CT is a powerful tool that supports in saving lives through accurate diagnosis. ALARA is the principle that ensures we always use it responsibly.
Questions about radiation safety or your upcoming scan? We are always happy to speak with you: