We sat down with Stefan Carl, MD. Stefan Carl to talk about his latest publication “Long-term evaluation of low-dose-rate (LDR) brachytherapy in localized prostate cancer” . He and his colleagues have conducted a retrospective multicenter analysis of LDR brachytherapy treatment in Germany.

Dr. med. Stefan Carl

Dr. Carl trained at the Department of Urology at the University of Heidelberg and is an experienced urologist with almost 25 years of experience in the field of LDR brachytherapy for the treatment of localized prostate cancer. He is one of the urologists in private practice at Emmendingen Urology and treats 100 patients a year with LDR brachytherapy at Emmendingen District Hospital.

The results of the study paint a clear picture of the potential of LDR brachytherapy in the treatment of patients with prostate cancer. The results could possibly even influence the German guidelines for the treatment of prostate cancer. We would like to talk to Dr. Stefan Carl about the results of the study and the data published in the journal “Die Urologie”.

INTERVIEW

Eckert & Ziegler:
Dr. Carl, thank you very much for your time. Your latest publication on LDR brachytherapy (LDR-BT) has aroused our curiosity. In it, you presented the oncological results of LDR-BT based on 700 patients. Please summarize for us how LDR-BT presents itself as a treatment option overall.

Dr. Stefan Carl:
Currently, LDR-BT is a curative treatment option for patients with localized prostate cancer. The European guidelines recommend LDR-BT for patients with low to intermediate risk prostate cancer. The advantage of LDR-BT compared to other treatment options such as prostatectomy and external radiation is the short duration of hospitalization and fewer side effects with the same chance of cure.

In LDR brachytherapy, small radioactive sources (seeds) are inserted into the prostate. Each seed has a length of 4.5 mm and a diameter of 0.8 mm and delivers a specific low dose of radiation to the surrounding tissue in the prostate. By placing the seeds homogeneously throughout the organ, the prostate is irradiated with the dose required to destroy the cancer cells. As the radiation is mainly delivered around the radioactive source, the surrounding tissue is spared.

Eckert & Ziegler:
You also mention the current study situation comparing LDR-BT with the treatment alternatives. How effective is it compared to radical prostatectomy (RP)?

Dr. Stefan Carl:
The two randomized controlled trials (RCT) published by Giberti et al. showed no significant differences in P-Ca patients treated with either radical prostatectomy or LDR-BT. To our knowledge, these are currently the only existing randomized trials comparing Px and LDR-BT.

Eckert & Ziegler:
This applies to low-risk prostate cancer. What about the treatment of patients with medium and high risk?

Dr. Stefan Carl:
Recently, a large prospective multicenter study by Viktorin-Baier (2021 ) was published that showed equally good oncological outcomes for intermediate-risk patients treated with LDR-BT. We were able to reproduce these results in our own study.

A recently published study by Morris et al. 2017 (ASCENDE Trial) compared external beam radiotherapy (EBRT) with LDR-BT and EBRT Boost. The study showed significant benefits for high-risk P-Ca patients treated with LDR + EBRT Boost compared to EBRT alone.

Sagittal view of the male pelvis during implantation of seeds for LDR brachytherapy

Eckert & Ziegler:
Are there any completed randomized control trials (RCTs) that have compared LDR-BT with other established treatment options?

Dr. Stefan Carl:
Apart from the three studies by Giberti and Morris mentioned above, there are no other randomized studies comparing curative treatment options for localized P-Ca. Unfortunately, several large trials designed to compare all four established primary treatment options, i.e. AS (active surveillance), radical prostatectomy, external beam radiotherapy and LDR brachytherapy, failed due to insufficient patient recruitment. The notorious German example would be the PREFERE trial, which suffered from recruitment problems and what we consider to be an overly complex trial design.

Eckert & Ziegler:
Can you give us a brief description of the specifics of your study? What parameters were taken into account, what methods were used and, above all, what results were obtained.

Dr. Stefan Carl:
We analyzed 618 patients with localized P-Ca who were treated with LDR-BT. The majority of our cohort were patients with low- and intermediate-risk prostate cancer. The primary endpoint of our study was biochemical relapse-free survival (bRFS). Simply explained, bRFS means that patients remain below their respective PSA nadir level after the procedure.
The key findings are that almost 90% of our patients had no PSA relapse after an estimated follow-up of 10 years. In particular, when comparing low and intermediate risk patients in monovariate and multiple regression models, there were no significant differences between intermediate and low risk patients in bRFS. However, our study is limited by the retrospective study design.

Eckert & Ziegler:
What motivated you to design this study? What did you want to achieve with it?

Dr. Stefan Carl:
Currently, there are dichotomous recommendations between German and European guidelines for prostate cancer regarding LDR-BT. The German recommendations are limited to low-risk P-Ca patients, but the current literature suggests a safe application also for intermediate-risk patients. This fact motivated us to report our promising results from a German perspective.

Eckert & Ziegler:
What impact do you think these results will have?

Dr. Stefan Carl:
Hopefully we will achieve a greater understanding and acceptance of LDR brachytherapy as a treatment option compared to radical surgery and external beam radiotherapy. Patients appreciate a safe treatment with a short hospital stay and a comparable cure rate. As far as international guidelines are concerned, Germany is far behind the EAU guidelines and the ABS guidelines. We therefore hope that the German guidelines will be adapted in the near future (LDR-BT recommendation for GS 7a).

Eckert & Ziegler:
Dr. Carl, thank you very much for your insights!

You can find the original interview at:
https://medical.ezag.com/en/insights/interview-with-dr-carl/

Further information on LDR brachytherapy for prostate cancer can also be found at:

https://www.krankenhaus-emmendingen.de/de/fachabteilungen/urologie
https://urologie-emmendingen.de/

Or in the video of the Eckert und Ziegler company