Beam's eye view based prostate treatment planning: is it useful?

Area of Science:

• Radiation Oncology
• Medical Imaging
• Prostate Cancer Treatment

Background:

• Prostate cancer is a prevalent malignancy frequently managed with radiation therapy.
• Optimizing treatment can enhance local control and minimize treatment-related complications.
• CT scans are routinely acquired for prostate cancer patients in treatment position post-simulation.

Purpose of the Study:

• To evaluate the impact and implications of 3-D Beam's Eye View (BEV) on field definition and blocking in prostate cancer radiation therapy.
• To assess the utility of BEV in normal tissue dosimetry, specifically for the bladder and rectum.
• To compare Dose Volume Histograms (DVH) generated using BEV with those from literature-based target volumes.

Main Methods:

• Analysis of 3-D Beam's Eye View (BEV) data for 12 consecutive prostate cancer patients.
• Utilizing multiple bony landmarks for aligning BEV images with simulator films.
• Employing Dose Volume Histograms (DVH) to assess dosimetry for the prostate, bladder, and rectum.

Main Results:

• Accurate alignment of BEV images requires multiple bony landmarks.
• Precise delineation of the prostate's inferior extent presents challenges.
• BEV-based treatment plans exhibit greater inter-patient variability than literature recommendations.
• No significant correlation was found between prostate volume and clinical stage in this cohort.
• BEV facilitates normal tissue dosimetry, enabling optimization of dose to the bladder and rectum.

Conclusions:

• Routine use of 3-D BEV in prostate cancer radiation therapy offers advantages for treatment planning and dosimetry.
• Challenges in precise volume entry and the need for robust landmark identification are noted.
• Further investigation into the routine application of BEV for prostate cancer treatment is warranted.