# Low-dose-rate seed brachytherapy

Source: https://onco.cc/technologies/ldr-seed-brachytherapy/  
OnCo record `ldr-seed-brachytherapy` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Dozens of rice-grain-sized radioactive seeds are implanted permanently in the prostate in a single procedure and deliver their dose over months.

## Summary

Permanent seed implantation uses iodine-125 or palladium-103 seeds placed through the perineum under ultrasound guidance in a one-off outpatient procedure. It is a curative option for low- and favourable intermediate-risk prostate cancer with control matching surgery and external radiotherapy, and is used as a boost in higher-risk disease (the ASCENDE-RT trial). The same seeds treat some lung and pancreatic tumours at surgery, and plaque brachytherapy with similar isotopes treats uveal melanoma.

## Fields

- Kind: Technology
- Status: established
- Last checked: 2026-09-16
- Tags: radiation-wave1
- Principle: Permanently implanted low-activity sources deliver a continuous low dose rate over weeks to months, exploiting repair differences between tumour and normal tissue.
- Since: 1980
- Strengths: Single procedure; Excellent long-term control in low-risk prostate cancer; Preserves continence for most
- Limitations: Urinary symptoms for months; Not suitable for large glands or prior TURP; Radiation safety precautions after implant

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Brachytherapy#Prostate_cancer

## Connected records

- cancers: [Prostate cancer](https://onco.cc/cancers/prostate/), [Uveal melanoma](https://onco.cc/cancers/uveal-melanoma/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/)
- technologies: [Brachytherapy](https://onco.cc/technologies/brachytherapy/)
- terms: [Brachytherapy (internal radiotherapy)](https://onco.cc/terms/brachytherapy-term/)

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