Challenges and opportunities for proton therapy during pregnancy

Abstract

During pregnancy, the use of radiation therapy for cancer treatment is often considered impossible due to the assumed associated fetal risks. However, suboptimal treatment of pregnant cancer patients and unjustifiable delay in radiation therapy until after delivery can be harmful for both patient and child. In non‐pregnant patients, proton‐radiation therapy is increasingly administered because of its favorable dosimetric properties compared with photon‐radiation therapy. Although data on the use of pencil beam scanning proton‐radiation therapy during pregnancy are scarce, different case reports and dosimetric studies have indicated a more than 10‐fold reduction in fetal radiation exposure compared with photon‐radiation therapy. Nonetheless, the implementation of proton‐radiation therapy during pregnancy requires complex fetal dosimetry for the neutron‐dominated out‐of‐field radiation dose and faces a lack of clinical guidelines. Further exploration and standardization of proton‐radiation therapy during pregnancy will be necessary to improve radiotherapeutic management of pregnant women with cancer and further reduce risks for their offspring.

Fetal dose assessment in a pregnant patient with brain tumor: A comparative study of proton PBS and 3DCRT/VMAT radiation therapy techniques

“…The findings of this study are consistent with previous studies that have shown the superiority of proton therapy in reducing the dose to normal tissues 20–25 . Our study demonstrates that intensity‐modulated proton therapy (IMPT) has the potential to significantly minimize fetal dose exposure during radiation therapy for pregnant patients with brain tumors, even when accounting for neutron dose generated from protons.…”

“…This poses challenges, particularly for the small proton therapy centers that are increasingly emerging. Hence, it is crucial to underscore the importance of collaborative case studies and the collective compilation of a comprehensive database, which ultimately benefits all patients 20–25 …”

Mini Review About Risks of Radiation in Medicine

“…Most of the time, the benefits of a precise diagnosis outweigh any possible risks associated with radiation (Michalet et al, 2022). When a fetus is in or close to a radiation beam during an examination that is at the higher end of the diagnostic dosage range, the risk-benefit equation requires limiting procedures and doses as much as practical while maintaining enough information to provide a correct diagnosis (Blommaert et al, 2024). This can be achieved by tailoring the examination to minimize the number of radiographs needed or, in the case of nuclear medicine, by promoting hydration and prompt radiopharmaceutical voiding through the urinary tract to minimize exposure to the fetus (Lowe, 2004).…”

Breast cancer during pregnancy—The oncologist's point of view

“… 10 In this context, proton radiotherapy is a recent development that allows considerable reduction in fetal exposure, although standardization is needed. 12 …”