Postoperative hypofractionated proton beam therapy to control recurrent paraganglioma at the jugular foramen: A case report

Paragangliomas (PGLs) are rare neuroendocrine tumors with malignant potential that may prove challenging to manage. Those arising at the jugular foramen are particularly problematic, especially if recurring after primary surgical treatment. Long-term follow-up is required, and effective treatment options for such recurrences are needed. The present study chronicles a recurring PGL of the jugular foramen that emerged after two surgeries. Alternative therapeutic strategies were accordingly pursued. This account of the related clinical course includes a discussion of the associated literature, focusing on the role of proton beam therapy (PBT) in PGL management and its benefits. The patient under treatment received hypofractionated PBT, utilizing intensity-modulated proton therapy/pencil-beam scanning techniques. The prescribed dose was 40 Gy in 15 fractions [equivalent dose in 2-gy fractions (EQD2), 42.09 Gy, assuming α/β=10) delivered to the gross tumor volume (GTV). Simultaneous integrated boosts to two inner subvolumes [GTV reduced by 2-mm margin, 50 Gy/15 fractions (EQD2, 55.49 Gy); and GTV reduced by 3-mm margin, 60 Gy/15 fractions (EQD2, 70.00 Gy)] took place as well. This process ensured precise radiation dosing, while adhering to strict dose constraints for adjacent critical structures. Hence, a quicker therapeutic response (aligned with that of stereotactic radiotherapy principles) was tenable, aiming for both tumor control and clinical improvement. Long-term follow-up is imperative to assess outcome durability. The aforementioned events illustrate the potential utility of advanced PBT techniques (namely pencil-beam scanning, hypofractionated regimens) in managing PGL recurrences of this type, especially if surgical options are limited or carry substantial risks. PBT offers a precise therapeutic alternative, with tumor control capabilities that promise to preserve critical tissues near key locations at the base of the skull.