Seed Radiotherapy for Prostate Cancer


Email Raji.Kooner@svha.org.au or call 02 8382 6980 for a confidential appointment.

The third form of radiotherapy is called low dose brachy, or seed therapy.

I was fortunate to spend about two weeks in Seattle, which is the world’s centre for seed therapy.

What this involves is usually a day or overnight procedure, the patient comes in, and via transperineal method, between the scrotum and the back passage, we put little seeds into the prostate, sometimes up to about 120 or more little radioactive pellets, and they’re inserted in the prostate, and so patients are usually discharged the next day1.

About a third of patients have quite marked frequency and urgency which settles down usually over a period of months. 2

A small percentage of patients can have quite severe, long term side effects, two or three percent3.

Generally, this sort of treatment is used for lower volume, lower grade cancers.4

It’s very important to have this technically perfected.

You have to have the seeds spaced out correctly or you can get cold spots.

We used to think that this treatment did not affect sexual function, but now we know that about 40% of patients have trouble with erectile function at forty years with this treatment, and it tends to be progressive. 5

Generally I would use this for patients who have a lower grade tumour, a lower volume tumour, and perhaps sometimes some older patients.

Patients are given the pros and cons of all these options and they generally select.

So really, with radiotherapy, there’s the external beam radiation, the high dose rate brachytherapy which is the wires that are given, and the low dose brachytherapy seed therapy.

We discuss all these options with patients, and patients generally decide which treatment is best for them, depending on their particular prostate, their particular prostate cancer, and the particular side effects they’re trying to avoid.

References

1. Brachytherapy for Prostate Cancer (Seed Implantation) - UPMC Hillman Cancer Center - https://hillman.upmc.com/cancer-care/prostate/treatment/radiation/prostate-seed-implant
2. Norihisa Katayama, Atsunori Yorozu, Takashi Kikuchi - Biochemical outcomes and toxicities in young men with prostate cancer after permanent iodine-125 seed implantation: Prospective cohort study in 6662 patients - Brachytherapy. 2023 May-Jun;22(3):293-303. doi: 10.1016/j.brachy.2022.12.001.
3. Elizabeth Thompson, William Barrett - Ultra-long-term toxicity of prostate brachytherapy - Brachytherapy Volume 20, Issue 3, May–June 2021, Pages 595-600 - https://doi.org/10.1016/j.brachy.2021.01.001
4. Hiroaki Kunogi, Yoshiaki Wakumoto, Terufumi Kawamoto - Focal low-dose-rate prostate brachytherapy for low- and intermediate-risk prostate cancer - J Contemp Brachytherapy. 2020 Dec; 12(6): 554–561 - doi: 10.5114/jcb.2020.101688
5. Cem Akbal, Ilker Tinay, Ferruh Simsek - Erectile dysfunction following radiotherapy and brachytherapy for prostate cancer: pathophysiology, prevention and treatment - Int Urol Nephrol . 2008;40(2):355-63. doi: 10.1007/s11255-007-9247-1.