8. Radiation therapy for craniopharyngioma

For much of the intervening decades since neurosurgery for CP was described, the debate largely revolved about the optimal treatment strategy, whether aggressive surgical resection or conservative surgery offered patients the best option. Among the two fundamental schools of thought regarding the optimal approach to treat craniopharyngioma, one advocated for GTR for all patients with radiation reserved for salvage therapy due to anticipated adverse effects of radiation [21]. The alternative management suggested was that of a subtotal resection or biopsy and cyst decompression in combination with adjuvant radiation therapy. Advantages of this approach include lower morbidity and improved quality of life [22]. Although the surgical goal remains maximal tumor resection with minimal morbidity, it is estimated that 33% of patients will present with some form of recurrence within the first few years. It is especially clear that radiation therapy is a key element of treatment for these patients with recurrent craniopharyngioma.

In a comprehensive review of a published series of CP patients, Yang et al. were able to demonstrate that subtotal surgery in conjunction with post-operative radiation results in improved survival in patients with CP [23]. This approach employing rather conservative surgery has the advantage of reducing the risks of hypopituitarism and hypothalamic injury. The results from various meta-analyses were corroborated and further expanded with evidence obtained from a large single-center series [24]. Conservative resection with adjuvant radiation was found to be a superior strategy in treating patients. Schoenfeld et al. reported a cohort of patients in which there was no significant difference between GTR and subtotal resection (STR) with radiation therapy (XRT) in terms of overall survival or progression-free survival at 2 years [25], with less endocrinological side effects observed in the STR group.

The key to progression-free survival appears to be conservative surgery with subsequent radiation therapy. Radiation therapy can include various regimens employing conventional external beam radiation therapy, stereotactic radiosurgery, or proton beam therapy. Although radiation offers patients the possibility of treatment with reduced morbidity and mortality, side effects of radiation include enlargement of a cystic tumor, fatigue, skin effects, increased intracranial pressure, and transient or permanent optic neuropathy. Moreover, radiation may have longterm effects such as hypopituitarism in 30–50% of patients, cranial nerve palsies, cerebrovascular diseases, and secondary malignancies. Fortunately, radiation therapy offers excellent outcomes with progressive-free survival between 5 and 10 years of 90% and 100%, respectively [26].
