Convert Curies to Gigabecquerels

Convert Curies (Ci) to Gigabecquerels (GBq) instantly and accurately.

Curies (Ci)
Gigabecquerels (GBq)

Conversion Formula

GBq = Ci × 37

About Curies

The curie (Ci) equals exactly 3.7 × 10¹⁰ Bq = 37 GBq, originally defined as the activity of 1 g of ²²⁶Ra. Still widely used in the US: ⁶⁰Co teletherapy sources are 5000-15000 Ci; ¹³⁷Cs blood irradiators are 1000-40000 Ci; NRC source licences for industrial radiography cite Ci limits. 1 Ci = 3.7 × 10¹⁰ Bq.

About Gigabecquerels

The gigabecquerel (GBq) equals 10⁹ Bq. Therapeutic radiopharmaceuticals are dosed in GBq: ¹⁷⁷Lu-PSMA prostate cancer therapy uses 7.4 GBq per cycle; ¹³¹I thyroid cancer ablation uses 3.7-7.4 GBq; ²²³Ra-dichloride (Xofigo) bone metastasis therapy ~3-5 GBq per injection. 1 GBq = 10⁹ Bq.

Quick Reference Table

Curies (Ci)Gigabecquerels (GBq)
1 Ci37 GBq
2 Ci74 GBq
5 Ci185 GBq
10 Ci370 GBq
25 Ci925 GBq
50 Ci1850 GBq
100 Ci3700 GBq

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