CyberKnife Dose Escalation Prostate Cancer Trial (CK-DESPOT)

February 19, 2025 updated by: Rachelle Lanciano M.D., Crozer-Keystone Health System

CyberKnife Dose Escalation for Unfavorable and High-risk Prostate Cancer

Stereotactic body radiation therapy (SBRT) has been employed in the treatment of prostate cancer. Multiple single institution experiences suggest high biochemical control rates with acceptable toxicity in low risk prostate cancer but efficacy data in unfavorable type prostate cancer is less convincing. CyberKnife-SBRT (CK-SBRT) can be used to escalate radiation dose delivery to the prostate while sparing normal tissue.

Study Overview

Status

Active, not recruiting

Intervention / Treatment

Detailed Description

The optimal radiation schedule for the curative treatment of prostate cancer remains unknown. Prostate cancer patients receiving radiation therapy are typically treated 5 days per week for 8-9 weeks. Recent data suggest that large radiation fraction sizes are radio-biologically favorable over lower fraction sizes in prostate cancer radiotherapy. The sensitivity of a tumor or normal tissue to fraction size of radiation can be approximated by the alpha-beta ratio. It has been suggested that the alpha/beta ratio for prostate cancer is actually as low as 1.5 implying that the current radiation therapy paradigm for prostate cancer treatment might be fundamentally flawed, as high fraction sizes would be expected to damage tumor more readily.

Typical prostate SBRT doses do not appear to have similar efficacy in higher risk prostate cancer suggesting even higher doses are required. Many techniques including dose escalated external beam radiation therapy (EBRT), proton therapy (PT) and brachytherapy have been employed to increase dose to the prostate. Data from the ASCEND-RT trial utilizing low dose rate brachytherapy boost showed a dramatic 21% improvement in biochemical control at 9 years favoring brachytherapy boost compared to conventional dose escalated EBRT radiation therapy. However, no corresponding benefit was identified in overall survival, incidence of bone metastases or prostate cancer specific mortality while a 3 fold increase in late urinary toxicity was noted.

SBRT is well tolerated with minimal acute and late side effects. In this protocol, CK-SBRT will be used to target the microscopic and gross disease in the prostate, seminal vesicles. An escalated dose of 40 Gy in 5 fractions will be delivered to the entire target volume while any nodules visible within the prostate gland on endorectal MRI will receive 50 Gy in 5 fractions.

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19083
        • Philadelphia CyberKnife

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Histologically confirmed adenocarcinoma of the prostate diagnosed within 360 days of enrollment.
  • Prostate Specific Antigen (PSA) documented within 90 days prior to registration.
  • Clinical staging completed within 90 days of registration.
  • No Nodal or Distant Metastases documented on CT or MRI of the pelvis and bone scan.
  • Unfavorable Risk Prostate Carcinoma as Described is documented.
  • No prior pelvic radiotherapy.
  • No prior Trans-urethral resection of the prostate (TURP).
  • Prostate volume < 100 cc
  • American Urologic Association (AUA) score < 20
  • No recent (within 5 years) or concurrent cancers other than non-melanoma skin cancers.
  • Patient must have no medical or psychiatric illnesses that would interfere with treatment or follow-up.
  • No implanted hardware adjacent to the prostate that would prohibit appropriate treatment planning and treatment delivery is allowed.
  • Candidate for rectal spacer placement

Exclusion Criteria:

  • Other cancer diagnosis other than non-melanoma skin cancer with 5 years
  • Prostate size greater than 100cc
  • AUA greater than 20
  • Implanted hardware impacting imaging
  • Metastatic prostate cancer
  • Contraindication to hormone therapy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Dose Escalated CyberKnife SBRT
DE-SBRT will be delivered using the CyberKnife robotic radiosurgery system. Patients will be treated with five SBRT treatments (8 Gy per fraction to the PTV, and 9-10 Gy per fraction to any nodules identified on endorectal MRI) over 7-10 days.
Radiation Therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Bladder and Rectal Toxicity using NCI common toxicity criteria version 4.0
Time Frame: 24 Months
Genitourinary or Bowel Toxicity as a result of radiation therapy will be reported using
24 Months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Biochemical Disease Free Survival
Time Frame: 24 Months
Time in months from completion of SBRT to biochemical failure
24 Months
Duration of local control
Time Frame: 24 Months
time in months from SBRT completion to local failure
24 Months
Distant Failure
Time Frame: 24 Months
time in months from SBRT completion to distant failure
24 Months
Disease Free Survival
Time Frame: 24 Months
time in months from the date that the patient is determined to be free of disease to the date of known disease recurrence for any measure of disease.
24 Months
Disease Specific Survival
Time Frame: 24 Months
time in months from completion of SBRT to death due to prostate cancer, other causes with active malignancy, or complications from treatment.
24 Months
Overall Survival
Time Frame: 5 years
ime in months from SBRT completion until death
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Chair: Rachelle Lanciano, MD, Philadelphia CyberKnife -Crozer Health
  • Principal Investigator: Rachelle Lanciano, MD, Philadelphia CyberKnife -Crozer Health

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 12, 2018

Primary Completion (Actual)

June 21, 2023

Study Completion (Estimated)

July 12, 2028

Study Registration Dates

First Submitted

January 28, 2019

First Submitted That Met QC Criteria

January 28, 2019

First Posted (Actual)

January 30, 2019

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

February 19, 2025

Last Verified

February 1, 2025

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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