Evolution of the MOMENTUM Study for Evidence-Based Implementation of MR-Guided Radiotherapy Using the 1.5 Tesla MR-Linac

PURPOSE/OBJECTIVE(S)

The international prospective 'Multiple Outcome Evaluation of Radiation Therapy Using the MR-Linac' (MOMENTUM) study (NCT04075305) was initiated in 2019 by seven hospitals and industry partner precision radiation medicine company, with the aim to facilitate evidence-based implementation of magnetic resonance (MR) guided radiotherapy using the 1.5 Tesla (T) MR-linear accelerator (Linac). Over the last four years, MOMENTUM has expanded to other institutions and the design and organization of MOMENTUM have evolved. Herein, we give an overview of the current status of MOMENTUM and study innovations that have been implemented to accelerate development and assessment of the 1.5T MR-Linac.

MATERIALS/METHODS

We summarized operational outputs of MOMENTUM, including site participation, data aggregation, academic output, and study design elements that have been introduced since 2019.

RESULTS

As of January 2023, 17 sites have joined and 10 sites are actively enrolling patients in MOMENTUM. The MOMENTUM infrastructure, which consists of prospectively collected clinical and technical patient data and patient reported outcomes, is increasingly being used for predicate studies, technical development studies, safety and early clinical evaluation, and hypothesis testing studies according to R-IDEAL. Over 3500 patients who received treatment for 33 different tumor sites have provided informed consent for using their data for scientific research and product development. The technical database currently includes over 190.000 items, including approximately 98,000 MRI scans and 33,800 dose plans. A total of 38 data requests have been accepted (2019: n = 1; 2020: n = 5; 2021: n = 10; 2022: n = 22), including technical studies focused on algorithmic development. The MOMENTUM infrastructure is also hosting prospective clinical studies, including the randomized HERMES trial (NCT04595019) and prospective UNITED study (NCT04726397). Recently, the 'Trials within Cohorts' (TwiCs) design has been implemented, which is well suited to perform pragmatic randomized trials. MOMENTUM has partnered with Kaiku Health, an electronic patient-reported outcomes application, to facilitate collection of patient reported toxicity.

CONCLUSION

Over the past four years, the MOMENTUM study has evolved into a unique platform, whose infrastructure is increasingly being used by clinicians, researchers, physicists and industry. Continuous efforts are being made to encourage the participation of new sites and the development of innovative tools to facilitate the conduct of well-designed trials that are expected to transform daily clinical practice.

Towards instantaneous cellular level bio diagnosis: laser extraction and imaging of biological entities with conserved integrity and activity

The prospect for spatial imaging with mass spectroscopy at the level of the cell requires new means of cell extraction to conserve molecular structure. To this aim, we demonstrate a new laser extraction process capable of extracting intact biological entities with conserved biological function. The method is based on the recently developed picosecond infrared laser (PIRL), designed specifically to provide matrix-free extraction by selectively exciting the water vibrational modes under the condition of ultrafast desorption by impulsive vibrational excitation (DIVE). The basic concept is to extract the constituent protein structures on the fastest impulsive limit for ablation to avoid excessive thermal heating of the proteins and to use strongly resonant 1-photon conditions to avoid multiphoton ionization and degradation of the sample integrity. With various microscope imaging and biochemical analysis methods, nanoscale single protein molecules, viruses, and cells in the ablation plume are found to be morphologically and functionally identical with their corresponding controls. This method provides a new means to resolve chemical activity within cells and is amenable to subcellular imaging with near-field approaches. The most important finding is the conserved nature of the extracted biological material within the laser ablation plume, which is fully consistent with in vivo structures and characteristics.

Surgical management of carotid body tumor

Carotid body tumor or chemodectoma is a slow-growing lesion; it should be diagnosed early to facilitate the technical surgical resection. When these lesions are large, the routine use of a carotid internal bypass shunt is advocated for their safe removal. With the newer vascular approaches, specifically the carotid internal bypass shunt, resection can be performed with acceptable risks. A patient with large bilateral carotid body tumors had successful resection of both these lesions.

[Susceptibility of leaves and fruits of tomato varieties and of their hybrids to attack by Phytophthora infestans]

1. The investigations were started to establish a correlation between the incidence of Phytophthora infestans (Mont.) de Bary on leaves and on fruits of tomatoes, the mechanism of the inheritance of the resistance and the number of responsible genes. 2. A close correlation was found between the spontaneous incidence on leaves and fruits and the results of artificial inoculation by the leaf-disc-test. The resistant types especially showed a remarkably low percentage of attack in all three tests. Resistant plants were successfully selected by means of the leaf-disc-test; the leaves as well as the fruits of the progeny were largely free from the disease. 3. The field-resistance of the variety 'Atom' was demonstrated to be due to a high degree of relative resistance of the leaves against the races T0 and T1. 4. The results obtained from F1-hybrids of 'Atom' with various more or less susceptible varieties indicate the participation of incompletely dominant genes. Since in the F2 a certain number of plants with a high degree of field-resistance could be selected, it is suggested that the field-resistance against Phytophthora infestans is based on a few genes only. From our results we conclude that principally two genes in the variety 'Atom' determine the field-resistance against the fungus. A participation of other modifier-genes can be supposed. We propose the gene-symbols Phf and Phf-2 for the Phytophthora-field-resistance.