This study is being done to evaluate whether cancer patients can safely and reliably receive proton radiation therapy while positioned upright. Proton therapy is an established form of radiation treatment, and the upright treatment system used in this study has been cleared by the U.S. Food and Drug Administration. The intent of this protocol is to observe the treatment methods, doses, and outcomes for the initial cohorts of patients treated with this upright device. This study will support research activities and evaluate feasibility as needed. Results of this study will be reported in the scientific literature but the investigators do not intend to report to the FDA for a new use or indication or change to the labeling; nor are the investigators required to do so.

Inclusion Criteria:

• Any cancer patient (children and adults) recommended for proton therapy.
• Participation in other clinical trials is allowed (including randomized trials of protons versus other treatments)

Exclusion Criteria:

• Any patient that doesn't meet the inclusion criteria

(i) Up to 450 participants are expected to be enrolled at Stanford-affiliated site(s).

(ii) The total number of participants expected to enroll across all sites is 450, as this is a single-site study conducted at Stanford-affiliated facilities.

(iii) Participants will be pediatric and adult patients with cancer who are being considered for treatment with upright proton therapy as part of their standard clinical care. These participants are appropriate for the study because the purpose is to evaluate the feasibility of delivering upright proton therapy in patients who would otherwise be eligible for proton radiation treatment.