Adaptive radiotherapy treats gynecologic cancers — including cervical, uterine, and ovarian malignancies — by re-imaging and re-optimizing the radiation plan at nearly every session to account for daily changes in bladder and bowel filling. At 5D Cancer Services, this is delivered on the Akesis Gemini 360 system, which pairs onboard imaging with real-time plan adjustment.
Why Do Gynecologic Organs Move So Much Between Treatments?
The uterus, cervix, and surrounding pelvic anatomy shift position daily depending on how full the bladder and rectum are — sometimes by more than a centimeter session to session. Because a typical course of pelvic radiation spans several weeks, a plan built from a single scan on day one can drift out of alignment with where the tumor and nearby organs actually sit on day fifteen.
The CDC estimates gynecologic cancers account for roughly 1 in 10 cancer diagnoses among women in the United States each year, spanning cervical, uterine, ovarian, vaginal, and vulvar disease. Uterine and cervical cancers are among the subtypes most commonly treated with pelvic radiation therapy.
How Does Adaptive Radiotherapy Address This Movement?
Each treatment session begins with cone-beam CT (CBCT) imaging captured on the machine itself, so the care team sees the day's actual anatomy before any dose is delivered. Learn more about how this works on our onboard imaging page. If the bladder, rectum, or tumor position has shifted from the original plan, the system can adjust the treatment shape to match — rather than treating a fixed volume based on outdated imaging.
This matters most for gynecologic cases because the bladder and rectum sit immediately adjacent to the treatment target. Published research in radiation oncology journals has associated image-guided, adaptive approaches with reduced acute gastrointestinal (GI) and genitourinary (GU) toxicity compared to non-adaptive delivery, since normal tissue can be more consistently avoided as anatomy shifts.
"Daily anatomy in the pelvis is not static — the bladder alone can change volume by a factor of two or more from one visit to the next," notes clinical literature from the American Society for Radiation Oncology (ASTRO) on image-guided pelvic radiotherapy. "Adapting the plan to that reality, rather than treating a fixed target, is central to limiting dose to healthy tissue."
What Does This Look Like for a Patient Day to Day?
| Step | What Happens |
|---|---|
| Initial imaging | Baseline CT establishes the tumor and organ positions |
| Daily CBCT | Onboard imaging captures that day's anatomy before treatment |
| Plan adaptation | The system adjusts the treatment shape to current anatomy |
| Delivery | Dose is delivered to the adapted, imaging-verified target |
| Repeat | This cycle occurs at each visit for the course duration |
Patients typically complete a defined number of sessions scheduled across several weeks; the exact number depends on the specific gynecologic diagnosis and treatment goals set by the care team. A full walkthrough of what to expect from consultation through follow-up is available on our patient journey page.
Does This Approach Apply to All Gynecologic Cases?
Adaptive radiotherapy is used for gynecologic malignancies where pelvic radiation is part of the treatment approach, and the same onboard imaging and dose-painting capabilities used for these cases are described in more detail on our conditions page. Whether adaptive radiotherapy is appropriate for a specific diagnosis is determined individually, based on imaging, staging, and the broader treatment plan.
Common Questions Patients Ask
- Is the daily imaging additional radiation exposure? CBCT imaging uses low radiation doses specifically calibrated for positioning verification, separate from the treatment dose itself.
- Does adapting the plan lengthen each appointment? Sessions account for imaging and plan verification as a built-in part of the visit.
- Who reviews the daily imaging? The treatment team reviews imaging and adaptation at each session as part of standard delivery.
More answers to common questions are collected on our FAQ page. Patients in St. George and Southern Utah with a gynecologic cancer diagnosis can contact 5D Cancer Services to discuss whether adaptive radiotherapy fits their treatment plan, including help with insurance verification and pre-authorization.