Radiation-Induced Retinopathy and Optic Neuropathy after Radiation Therapy for Brain, Head, and Neck Tumors: A Systematic Review

Background: Patients with brain, head, and neck tumors experience a decline in their quality of life due to radiation retinopathy and optic neuropathy. Little is known about the dose–response relationship and patient characteristics. We aimed to systematically review the prevalence of radiation retinopathy and optic neuropathy. Method: The primary outcome was the pooled prevalence of radiation retinopathy and optic neuropathy. The secondary outcome included the effect of the total radiation dose prescribed for the tumor according to the patient’s characteristics. Furthermore, we aimed to evaluate the radiation dose parameters for organs at risk of radiation retinopathy and optic neuropathy. Results: The pooled prevalence was 3.8%. No retinopathy was reported for the tumor’s prescribed dose of <50 Gy. Optic neuropathy was more prevalent for a prescribed dose of >50 Gy than <50 Gy. We observed a higher prevalence rate for retinopathy (6.0%) than optic neuropathy (2.0%). Insufficient data on the dose for organs at risk were reported. Conclusion: The prevalence of radiation retinopathy was higher compared to optic neuropathy. This review emphasizes the need for future studies considering retinopathy and optic neuropathy as primary objective parameters.

Diagnosis and treatment of refractory pituitary adenomas: a narrative review

Although aggressive pituitary adenomas (PAs) have been proposed and widely discussed for more than a decade, there is no general agreement regarding their definition, diagnosis or management. As one of the largest pituitary centers in China, we have diagnosed and treated more than fifty cases of aggressive PA and 3 pituitary carcinomas in the past 5 years and proposed a new term, i.e., refractory PAs, to define these adenomas. The definitions of aggressive and refractory PAs overlap with each other, though there are some differences between them. We interpret the definition for refractory PA in this review, emphasizing that more attention and early identification of these adenomas are needed. Although temozolomide (TMZ) has been used to treat pituitary carcinomas and refractory PA since 2006, which has significantly improved the prognosis of these patients, treatment of refractory PA is a tremendous challenge for endocrinologists and neurosurgeons. Overall, refractory PA is defined as PA with a Ki-67 labeling index ≥3%, a faster growth rate than that of normal PA, infiltration of surrounding tissues, recurrence or regrowth in the early postoperative period, and continued growth and/or secretion of excessive hormones despite attempts to control it. These criteria for refractory PA are stricter than for aggressive PA. The diagnosis and treatment of refractory PA requires the collaboration of a multidisciplinary team to achieve the best results.

Safety and efficacy of fractionated stereotactic radiotherapy and stereotactic radiosurgery for treatment of pituitary adenomas: A systematic review and meta-analysis

Accumulated studies have not provided conclusive evidence in regards to the comparative efficacy and safety of fractionated stereotactic radiotherapy and stereotactic radiosurgery for treatment of pituitary adenomas. To address this issue, we performed a meta-analysis with eight studies identified from Medline, PubMed, Cochrane, Google Scholar, and published up to September 17, 2015. Eligible studies reported the disease control rate, endocrine cure rate (for functional adenomas), the rate of occurrence of new-onset hypopituitarism, and visual disturbance rate in patients treated with either stereotactic radiosurgery or fractionated stereotactic radiotherapy. Eight studies enrolled a total of 634 patients with pituitary adenoma, 273 patients underwent a stereotactic radiosurgery and 361 patients underwent fractionated stereotactic radiotherapy. No significant differences were found in efficacy measures, such as disease control rate and endocrine cure rate, between stereotactic radiosurgery and fractionated stereotactic radiotherapy (OR=1.156, p=0.666; OR=0.659, p=0.153, respectively). Additionally, meta-analysis of safety measures, such as the rate of new-onset hypopituitarism and visual disturbance rate, did not show significant differences between different treatments (OR=1.365, p=0.469; OR=0.872, p=0.845 respectively). In conclusion, both stereotactic radiosurgery and fractionated stereotactic radiotherapy have comparable efficacy and safety in the management of pituitary adenoma patients.