Observational Study on Extreme Hypofractionation for Localized Prostate Cancer

About This Trial

This study is testing a shorter course of radiation therapy that delivers focused, high doses over just a few sessions instead of several weeks.
It is designed for men with localized prostate cancer that is considered intermediate- or high-risk, meaning the cancer has not spread to other parts of the body.
Researchers want to see if this treatment is safe and effective for real-world patients, including men with larger prostates or mild urinary symptoms who are often left out of clinical trials.
Before considering this study, you should know that you must be able to safely have an MRI scan, and you cannot participate if you have previously received surgery, chemotherapy, or radiation for your prostate cancer.

More Information

Radiotherapy (RT) is an established treatment option for localized prostate cancer (PCa), with cure rates similar to those of radical prostatectomy.
In the last decade, conventionally fractionated RT (1.8-2.0 Gy per fraction to 78-80 Gy) has been replaced by moderately hypofractionated RT (2.3-3.65 Gy per fraction to 56-70 Gy).
The rationale behind this change is the scientific level 1 evidence that a higher dose per fraction may improve the cost-benefit of RT due to the specific radiobiology of PCa (a lower alpha/beta than that of adjacent healthy tissues).
Additionally, there is a practical advantage both for patients and the radiation department due to a reduced number of fractions.
More recently, extreme hypofractionation or stereotactic body radiotherapy (SBRT) (7-9.5 Gy per fraction to 36-43 Gy in 4-7 fractions) has been introduced as RT modality, and proved to be an effective and safe treatment option for patients with low and intermediate clinically-localized PCa, with similar incidence of late toxicity and 5-year disease free survival outcomes when compared to hypofractionated and conventional radiotherapy regimens.
International guidelines endorse extreme hypofractionated SBRT as routine treatment option for low and intermediate risk PCa patients.
For high-risk prostate cancer, preliminary results of ongoing prospective studies are promising, but these data are not yet mature enough to recommend extreme hypofractionated SBRT in high-risk prostate cancer.
Upon this, ongoing prospective trials handle strict eligibility criteria hereby selecting patients with few comorbidities.
This may not necessarily fully reflect the real life patient population.
Indeed, patients with a large prostate size, a history of transurethral resection of the prostate (TURP), or 'significant' urinary baseline symptoms may be at risk for experiencing increased toxicity.
Based on this concern, these patients were excluded from ongoing clinical trials.
However, whether these patients will really develop more toxicity, is a theoretical concern, not yet based on clinical evidence.
It is our hypothesis that using modern radiotherapy such as volumetric arc therapy (VMAT) and image-guided radiotherapy (IGRT) - both standard technologies at the Radiation-Oncology department in Leuven University Hospitals - extreme hypofractionated SBRT can be successfully implemented in the treatment of intermediate risk and a select group of high-risk PCa patients and/or patients with pre-existing urinary morbidity.

Who Can Enroll

Gender: Male
Who This Trial is For: This study is testing a shorter course of radiation therapy that delivers focused, high doses over just a few sessions instead of several weeks.

Study Details

Start Date: April 25, 2022
Lead Sponsor: Universitaire Ziekenhuizen KU Leuven

Full Eligibility Criteria

Inclusion Criteria

men ≥ 18 years
histologically confirmed clinically localized adenocarcinoma of the prostate
intermediate- or high-risk PCa, defined as OR at least one of the following criteria:
clinical stage: cT2a-c, cT3a or cT3b (AJCC 7th edition)
Gleason Score ≥ 7 (ISUP grade group 2 or higher) OR at least two of the following criteria:
clinical stage: cT1c (AJCC 7th edition)
Gleason Score ≥ 7 (ISUP grade group 2 or higher)
calculated risk for lymph node involvement (Roach formula) 18) is allowed, however should be discussed with the principal investigator and left to the discretion of the treating physician
high risk of lymph node involvement, as calculated with the Roach formula ≥ 35% (https://www.evidencio.com/models/show/1144) Of note, in case of ambiguity of regional lymph node involvement on CT or MRI findings (when Roach formula is 2
patients with severe inflammatory bowel disease rendering radiotherapy impossible (active Crohn's Disease or Ulcerative Colitis), or patients known with ataxia telangiectasia
implanted hardware or other material that would prohibit appropriate treatment planning or treatment delivery, in the investigator's opinion
prior or concurrent invasive malignancy (except non-melanomatous skin cancer) or lymphomatous/hematogenous malignancy unless continually disease-free for a minimum of 5 years. (carcinoma in situ of the bladder or oral cavity is permissible)