This research is being done to determine the safety and feasibility of using a type of radiation guided by magnetic resonance imaging (MRI) and chemotherapy to treat patients with gastric and breast cancer. The name of the radiation machine involved in this study is the MRIdian Linear Accelerator.

This is a master clinical protocol evaluating magnetic resonance (MR) image guided radiation in patients with gastric and breast cancer.

In this research study, the investigators are researching if getting an MRI during radiation is a feasible way to delivery radiation. In this research study, a MRI done during treatment will help doctors adapt the radiation to target the most precise spot where the cancer is located.

The research study procedures include:

• Screening for eligibility
• Study treatment including evaluations
• Follow up visits
• Questionnaires

This is a Phase I/II clinical trial. A Phase I clinical trial tests the safety of investigational radiation treatment and also tries to define the appropriate dose of the investigational radiation treatment to use for further studies. "Investigational" means that the way the radiation treatment is delivered is being studied.

This research study is a Feasibility Study, which means it is the first-time investigators at this institution are examining this type of MR-guided radiation. Investigators at other hospitals and academic centers are already using this type of radiation.

The U.S. Food and Drug Administration (FDA) has approved this radiation machine and these drugs as treatment options for gastric and breast cancer.

Inclusion Criteria:

• Participants must have histologically or cytologically confirmed malignancy requiring radiation
• Age 18 years of older
• ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A)
• Ability to understand and the willingness to sign a written informed consent document.
• Any further criteria listed in the specific disease site cohort

Exclusion Criteria

• History of allergic reactions attributed to gadolinium-based IV contrast

  -- Note: If patient will not receive contrast, this is not applicable and kidney function will not affect eligibility

• Severe claustrophobia or anxiety

• Participants who cannot undergo an MRI

• Any other exclusion criteria listed in the specific disease site cohort

The Dana-Farber / Harvard Cancer Center encourages and supports the responsible and ethical sharing of data from clinical trials. De-identified participant data from the final research dataset used in the published manuscript may only be shared under the terms of a Data Use Agreement. Requests may be directed to Sponsor Investigator or designee. The protocol and statistical analysis plan will be made available on Clinicaltrials.gov only as required by federal regulation or as a condition of awards and agreements supporting the research.

Data can be shared no earlier than 1 year following the date of publication

DFCI - Contact the Belfer Office for Dana-Farber Innovations (BODFI) at innovation@dfci.harvard.edu