ESTRO 2024 - Abstract Book

S5572

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

An intra-fraction CBCT protocol was developed to review post treatment to assess possible positional variation during treatment and prove patient stability.

Catalyst Surface Guided Radiation Therapy (SGRT) was utilised to detect any gross error and assist with initial patient setup. iGuide, Hexapod, 6 degrees of freedom couch correction was used to correct rotational errors in patient setup.

Results:

A treatment Planning Template was developed which achieved the plan criteria as defined by both departmental and international guidelines as assessed using the Dosimetric Criteria embedded into the planning template. The class solution achieved clinically acceptable plans (allowing only minor violations on target volumes and organs at risk) over 90% of the time. Treatment plans were delivered on an arc check on our departmental linear accelerators using routine Physics Quality Assurance (QA) methods. Plans were delivered with a mean delivery time of 90 seconds and all plans passed Physics QA with a mean pass rate of 95% using Gamma Analysis with 2% and 2mm. A bladder and bowel protocol was developed and implemented after consultation with Radiation Oncologists, Radiation Therapists, nursing staff and dietician. Routine inclusion of daily Movicol for 2 weeks prior to CT simulation for all patients resulted in consistent rectum sizes. Microlax enema was reserved for unacceptable rectal sizes of greater than 4cm diameter.

Patient stability was assessed using data collected from the pre-treatment verification CBCT and Intra-Fraction CBCT.

Conclusion:

We have successfully implemented a safe and efficient Prostate SABR program in our regional cancer centre without the use of real-time seed-tracking.

The development of a treatment planning template allowed shorter planning time frames and more consistent treatment plans.

The inclusion of a regimented bladder and bowel protocol allowed more consistent bladder and bowel sizes as verified on Pre treatment CBCT and Intra-Fraction CBCT.

The use of Intra-Faction CBCT in conjunction with SGRT allowed verification of patient stability during treatment.

Keywords: Prostate, Stereotactic, Stability

References:

1. eviQ: Prostate adenocarcinoma definitive ultra-hypofractionated stereotactic EBRT