MR-guidance in Chemoradiotherapy for Cervical Cancer

Treatment-related bladder toxicity,Treatment-related bowl toxicity

Concurrent chemoradiotherapy (CCRT), consisting of external beam radiotherapy (EBRT) and
 chemotherapy, followed by brachytherapy (BT) is the standard of care for patients with
 locally advanced cervical carcinoma. In current clinical practice, conventionally, one
 radiotherapy plan based on the initial planning computed tomography (CT) and magnetic
 resonance imaging (MRI) scan of the pelvis is applied for the complete 5-6 weeks of EBRT.
 However, there is a high degree of cervix and uterus motion in the pelvis due to different
 fillings of the bladder and the bowel. Consequently, large safety margins are required to
 compensate for organ movement, potentially leading to higher toxicity. Lately, daily
 high-quality cone-beam CT (CBCT) guided adaptive radiotherapy, aided by artificial
 intelligence (AI), became clinically available. Due to the improved soft-tissue contrast, the
 treatment plan can now be online adapted to the current position of the tumor and the
 adjacent organs-at-risk (OAR), while the patient is lying on the treatment couch. Moreover,
 the German Research Cancer Center offers the unique possibility of additional weekly magnetic
 resonance imaging (MRI) in treatment position using a shuttle system. Daily CBCT-adapted EBRT
 in combination with weekly MRI in treatment position might therefore offer superior sparing
 of surrounding OAR and consequently reduction of treatment-associated side-effects.
 
 However, to our knowledge, no toxicity data for daily CBCT/AI adaptive EBRT of locally
 advanced cervical cancer with additional MR-guidance exists. The AIM-C1 trial therefore aims
 to assess the potential of daily CBCT adaptive and AI aided EBRT combined with additional
 weekly offline MR-guidance in treatment position using a shuttle system.