Daily AI-Based Treatment Adaptation under Weekly Offline MR Guidance in Chemoradiotherapy for Cervical Cancer 1: The AIM-C1 Trial

Abstract

(1) Background: External beam radiotherapy (EBRT) and concurrent chemotherapy, followed by brachytherapy (BT), offer a standard of care for patients with locally advanced cervical carcinoma. Conventionally, large safety margins are required to compensate for organ movement, potentially increasing toxicity. Lately, daily high-quality cone beam CT (CBCT)-guided adaptive radiotherapy, aided by artificial intelligence (AI), became clinically available. Thus, online treatment plans can be adapted to the current position of the tumor and the adjacent organs at risk (OAR), while the patient is lying on the treatment couch. We sought to evaluate the potential of this new technology, including a weekly shuttle-based 3T-MRI scan in various treatment positions for tumor evaluation and for decreasing treatment-related side effects. (2) Methods: This is a prospective one-armed phase-II trial consisting of 40 patients with cervical carcinoma (FIGO IB-IIIC1) with an age ≥ 18 years and a Karnofsky performance score ≥ 70%. EBRT (45–50.4 Gy in 25–28 fractions with 55.0–58.8 Gy simultaneous integrated boosts to lymph node metastases) will be accompanied by weekly shuttle-based MRIs. Concurrent platinum-based chemotherapy will be given, followed by 28 Gy of BT (four fractions). The primary endpoint will be the occurrence of overall early bowel and bladder toxicity CTCAE grade 2 or higher (CTCAE v5.0). Secondary outcomes include clinical feasibility, quality of life, and imaging-based response assessment.

Clinical Workflow of Cone Beam Computer Tomography-Based Daily Online Adaptive Radiotherapy with Offline Magnetic Resonance Guidance: The Modular Adaptive Radiotherapy System (MARS)

“…Currently, clinical trials are underway to further validate the feasibility and efficacy of the presented workflow and to explore its potential benefits for a range of cancer types, such as cervical cancer within the AIM-C1 trial (daily AI-based treatment adaptation under weekly offline MR guidance in chemoradiotherapy for cervical cancer) [ 39 ].…”

Adaptive Radiotherapy: Next-Generation Radiotherapy

“…Offline ART could utilize sophisticated imaging modalities such as CBCT, MRI, or PET imaging to acquire high-resolution images of the patient’s anatomy [ 13 , 14 ]. But it could also rely on a re-simulation using the simulation CT as in conventional radiotherapy.…”

“…ART using PET scans with hypoxia-sensitive radiotracers such as fluoromisonidazole (FMISO), fluoroazomycin arabinoside (FAZA), and pentafluorinated etanidazole (EF5) can therefore enhance treatment response [ 73 ]. Recently, a trial protocol was published about the integration of weekly offline MRIs into the CBCT-guided ART of cervical cancer patients with Ethos, allowing additional functional assessment of tissue perfusion, hypoxia, or cellular density [ 14 ]. As time goes on, there might not be a clear line between different ART imaging modalities, and different imaging and treatment modalities could be combined to be more resource-effective.…”