Evaluation of Radiation Therapy Positioning System (RTPS) in Patients With Localized Prostate Cancer

The high precision of planned radiotherapy treatments requires accurate positioning of the prostate in order to ensure that the tightly conformed dose distribution does not miss the prostate and result in either significant tumor underdosage, an increased dose to the rectum or bladder, or both. Precise delivery has been addressed using a variety of pre-treatment localization systems. The most direct localization of the prostate involves the use of ultrasound, computed tomography (CT), or radiography of permanently implanted fiducial markers.

In this study the safety and performance of a novel investigational tracking system will be evaluated. The Radiation Therapy Positioning System (RTPS) is a radioactive tracking system integrated into the radiotherapy set-up workflow. The System is composed of the Clinical Positioning System (CPS) and a radioactive soft tissue implanted fiducial (Blip), which is permanently implanted in the prostate. By tracking the implanted Blip, the CPS can monitor positional changes prior to and during the treatment.

The accuracy of the RTPS localization will be compared to the CBCT in at least 5 radiation therapy sessions per patient.

Inclusion criteria

• Diagnosis of adenocarcinoma of the prostate.
• Male, age greater than or equal to 45 years.
• Intact prostate of at least 30g, as estimated by physical estimation and/or ultrasound.
• ECOG (Eastern Cooperative Oncology Group) performance status of 0 or 1.
• Patients must be planned to have external beam radiation as the definitive treatment for their prostate cancer with treatment set-up verification according to a locally fixed protocol.
• Patients must have anatomy that will allow an adequate pelvic imaging by CBCT as well as CT scanning.
• Organ confined or locally advanced prostate cancer with clinical N category 0 or x, M category 0 or x.
• Ability to comply with study visit schedule.
• Patient (or legal guardian) understands the study requirements and the investigational procedure and provides written Informed Consent before any study-specific tests or procedures are performed.

Exclusion criteria

• Past history of abdominoperineal (A-P) resection.
• Planned course of treatment using brachytherapy (permanent brachytherapy seeds or high dose rate [HDR] brachytherapy).
• Allergy to local anesthetics.
• History of chronic prostatitis.
• Patients with history of recent acute and/or chronic bleeding disorders.
• Patients on therapeutic anti-coagulants or anti-platelet therapy, not including aspirin or dipyridamole.
• Patients for which the maximum body width or the maximum anterior-posterior depth in the abdomino-pelvic region is greater than 40 cm. (Measurements will be made visually with a ruler.)
• Patients with a body habitus that the CT bore of the CT/LINAC treatment machine cannot accommodate.
• Patients with a prior history of pelvic or prostate radiotherapy.
• Patients who have had prior prostate surgery other than a TUR.
• Cognitively impaired patients who cannot give informed consent.
• Patients with hip replacement by a metal prosthesis.
• Patient has participated in, or is planned to participate in, any investigational drug or device study within the past or next 2 months.
• Patient who has more than 1μCi of any injected or implanted radioactive material within his body.