Published in the Red Journal, this retrospective study analyzed seven pregnant patients (4 brain tumors and 3 head and neck tumors) treated with XRT and modeled the equivalent dose that would have been delivered to the fetus with proton radiation compared to XRT. The results showed that the average measured fetal equivalent dose, accounting for photons and neutrons, for the brain plans was 0.4 mSv for PBS-PRT and 7 mSv for XRT; for the head and neck plans, it was 6 mSv and 90 mSv for PBS-PRT and XRT respectively. The PBS-PRT plans were preferred by the physicians for both tumor coverage and normal tissue sparing. Fetal equivalent dose is reduced by approximately a factor of 10 with PBS-PRT than with XRT without making any compromises in treatment planning objectives. The authors suggested a change of practice to utilize PBS-PRT as the new standard for treating pregnant patients with brain or head and neck tumors compared to XRT.