The incidence of second brain tumors related to cranial irradiation.

Secondary brain tumor (SBT) is a devastating complication of cranial irradiation (CI). We reviewed the literature to determine the incidence of SBT as related to specific radiation therapy (RT) treatment modalities. The relative risk of radiation-associated SBT after conventional and conformal RT is well established and ranges from 5.65 to 10.9; latent time to develop second tumor ranges from 5.8 to 22.4 years, depending on radiation dose and primary disease. Theories and dosimetric models suggest that intensity-modulated radiation therapy may result in an increased risk of SBT, but clinical evidence is limited. The incidence of stereotactic radiosurgery-related SBT is low. Initial data suggest that no increased risk from proton therapy and dosimetric models predict a lower incidence of SBT compared with photons. In conclusion, the incidence of SBT related to CI is low. Longer follow-up is needed to clarify the impact of intensity-modulated radiation therapy, proton therapy and other developing technologies.

The use of proton therapy in the treatment of head and neck cancers.

External beam radiation therapy is a commonly utilized treatment modality in the management of head and neck cancer. Given the close proximity of disease to critical normal tissues and structures, the delivery of external beam radiation therapy can result in severe acute and late toxicities, even when delivered with advanced photon-based techniques, such as intensity-modulated radiation therapy. The unique physical characteristics of protons make it a promising option in the treatment of advanced head and neck cancer, with the potential to improve sparing of normal tissues and/or safely escalate radiation doses. Clinical implementation will require the continued development of advanced techniques such as intensity-modulated proton therapy, using pencil beam scanning, as well as rigorous methods of quality assurance and adaptive techniques to accurately adjust to changes in anatomy due to disease response. Ultimately, the widespread adaptation and implementation of proton therapy for head and neck cancer will require direct, prospective comparisons to standard techniques such as intensity-modulated radiation therapy, with a focus on measures such as toxicity, disease control, and quality of life.

The use of proton therapy in the treatment of gastrointestinal cancers: liver.

This article reviews the role of proton therapy in the treatment of primary liver cancer focusing on hepatocellular carcinoma (HCC). The dose-sparing physical properties of protons are of great advantage in the treatment of HCC. To date, the clinical experience with the use of protons for HCC is encouraging. Most studies come from East Asia and show improved local control and survival with low toxicity. More importantly, when high-enough radiation doses are delivered to early liver cancers, a substantial fraction of patients are alive at 5 years, results not dissimilar from surgical resection. The technical details related to the use of proton therapy for HCC are also reviewed. The combination of proton therapy with other locoregional or systemic therapies is currently being tested and holds promise to improve survival while maintaining an acceptable level of toxicity.

Proton therapy and radiation sensitivity in dyskeratosis congenita.

BACKGROUND: Patients with dyskeratosis congenita (DC) have an increased risk of cancer, but also exhibit heightened radiation sensitivity. Proton therapy improves sparing of normal tissue, and thus may reduce radiation toxicity in patients with DC. OBSERVATIONS: We present a pediatric patient with DC who was treated with adjuvant proton therapy for oropharyngeal cancer. He experienced more severe skin toxicity and mucositis than expected. With reduced fractions per week and extensive supportive care, he completed the full radiation course. CONCLUSIONS: Proton therapy can improve normal tissue sparing, allowing successful delivery of radiation therapy in DC patients.

Acute toxicity profile of patients with low-grade gliomas and meningiomas receiving proton therapy.

OBJECTIVES: Proton therapy is an emerging treatment modality. We studied its acute side effects on patients with low-grade gliomas and meningiomas. MATERIALS AND METHODS: Twenty-three patients diagnosed with low-grade gliomas or meningiomas enrolled in an Institutional Review Board-approved prospective proton treatment protocol (NCT01024907) were treated and followed between April 2010 and August 2011. Patients received 54 Gy (relative biological effectiveness) in 1.8 Gy (relative biological effectiveness) per fraction and were assessed at the time of consult, weekly during treatment, and at 1, 3, 6, and 9 months posttreatment. At each clinic visit, nursing completed a "Symptom Assessment/Grading" table. Symptoms were graded based on National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Fatigue: At on-treatment visit (OTV) week 6, 13 patients had grade 1 and 6 patients had grade 2 fatigue. At 1-month follow-up, 3 patients had grade 1 and 1 patient had grade 2 fatigue. At each timepoint, 1 patient had grade 3 fatigue. Nausea: At OTV week 3, 5 patients experienced grade 1 nausea. At OTV week 6, 3 patients experienced grade 1 nausea. Headache: At OTV week 3, 10 patients had grade 1 headaches. At OTV week 6, 4 patients experienced grade 1 headaches and 1 patient by follow-up month 1. One to 2 patients experienced grade 2 headaches at each timepoint. At OTV week 3, 1 patient experienced a grade 3 headache. CONCLUSIONS: Our results suggest that proton therapy for patients with low-grade gliomas and meningiomas has a favorable acute toxicity profile-most patients experienced mild fatigue, headache, and insomnia that largely resolved by 1-month posttreatment.