Review of photon and proton radiotherapy for skull base tumours

Abstract

a b s t r a c tAn extremely large variety of benign and malignant tumours occur at skull base; these tumour lesions are in the proximity to structures deputed to relevant physiologic functions, limiting extensive surgical approaches to this body district. Most recent progresses of surgery and radiotherapy have allowed to improve local control with acceptable rates of side effects. Various photon radiotherapy techniques are employed, including 3-dimensional conformal radiotherapy, intensity modulated radiotherapy (IMRT), stereotactic radiotherapy (SRT) and brachytherapy that is manly limited to the treatment of primary or recurrent nasopharyngeal carcinoma. Proton beam radiotherapy is also extensively used thanks to its physical characteristics. Our review, focusing in particular on meningioma, chordoma, and chondrosarcoma, suggests that proton therapy plays a major role in the treatment of malignant tumours whereas photon therapy still plays a relevant role in the treatment of benign tumour lesions.

Locally advanced epithelial sinonasal tumors: The impact of multimodal approach

“…In addition, several disease‐ and patient‐related factors need to be considered before giving recommendations: recurrent tumors appear to be more radioresistant than their initial clones for biological reasons, which in part are associated to microvascular alterations related to previous treatments. These aspects underline the need for well‐targeted approaches to overcome enhanced radio‐ resistance and hypo‐oxygenation, such as the use of particle therapy (i.e., proton or carbon ion therapy) . Another major issue with re‐irradiation is that local recurrences are often located within previously high‐dose radiated volumes and in close proximity to critical structures such as the brainstem and optic tracts, thus restricting the RT dose that can be safely delivered with curative intent .…”

“…These aspects underline the need for well-targeted approaches to overcome enhanced radioresistance and hypo-oxygenation, such as the use of particle therapy (i.e., proton or carbon ion therapy). 43 Another major issue with re-irradiation is that local recurrences are often located within previously high-dose radiated volumes and in close proximity to critical structures such as the brainstem and optic tracts, thus restricting the RT dose that can be safely delivered with curative intent. 44 In short, the chances of patient cure should be evaluated against likely sequelae.…”

The role of dose escalation and proton therapy in perioperative or definitive treatment of chondrosarcoma and chordoma: An analysis of the National Cancer Data Base

“…The principal studies in proton therapy for these tumors, primarily in the skull base, appear to show more favorable outcomes in comparison with traditional photons . Using a combination of photons and protons, researchers from Massachusetts General Hospital reported 5‐year local relapse–free survival rates of 73% for chordoma and 80% for chondrosarcoma with total doses ranging from 66 to 83 GyRBE .…”

“…Cancer February 15, 2019 The principal studies in proton therapy for these tumors, primarily in the skull base, appear to show more favorable outcomes in comparison with traditional photons. 11 Using a combination of photons and protons, researchers from Massachusetts General Hospital reported 5-year local relapse-free survival rates of 73% for chordoma and 80% for chondrosarcoma with total doses ranging from 66 to 83 GyRBE. 12 In a contemporary study at Loma Linda University Medical Center using a proton dose of 65 to 79 GyRBE, 5-year LC and OS rates were 59% and 79%, respectively, for chordoma and 75% and 100%, respectively, for chondrosarcoma.…”

The management of skull base tumours: A challenge claiming for a multidisciplinary collaboration

“…As far as technical aspects are concerned, various radiation types can be used nowadays. Conventional and innovative photon and proton techniques are described in the article of Fossati et al 7 They enter into details of the most effective and innovative radiation modalities including intensity modulated radiotherapy (IMRT), stereotactic radiotherapy, brachytherapy and, in particular, protontherapy reporting available results in terms of local control, survival and side effects. The paper by Mizoe et al 8 is very informative on the most recent data of carbon ion therapy that is one of the last evolutions of radiation therapy, being able to combine an optimal spatial dose distribution with a high radiobiological effectiveness.…”