Patterns of Failure in Pediatric Craniopharyngioma with Surgery Alone

Abstract

<h3>Purpose/Objective(s)</h3> Though pathologically benign, craniopharyngiomas are frequently recurrent even with complete surgical resection. Thus, postoperative adjuvant radiation therapy (RT) is often employed for durable local control, with conventional irradiation to the surgical bed of both cystic and solid components of the initial tumor. However, this carries risk of high morbidity in the form of late effects, including learning disabilities, neuroendocrine dysfunction, and secondary malignancy. There exists a potential opportunity to reduce radiotherapy-induced toxicity if radiotherapy can be constrained to the initial solid tumor bed and a minimal cystic component within the sellar region. Motivated by this, we sought to characterize the pattern of recurrence in craniopharyngiomas managed surgically without adjuvant therapy. <h3>Materials/Methods</h3> Medical records of 81 patients with craniopharyngioma diagnosed between 1979 and 2021 were reviewed. We identified a subset of patients treated with surgical resection alone who subsequently experienced local recurrence on surveillance MRI. Patients with unavailable pre-operative or recurrent imaging were excluded. Contours of both cystic and solid components of the initial tumor were created utilizing pre-operative MRI, and the recurrent tumor MRI was fused with these contours using deformable image registration. <h3>Results</h3> Fourteen patients who had received surgical resection without adjuvant RT were identified, with a median age of 10.1 years old. An endoscopic surgical approach was used in 8 (57.1%) patients, while open microsurgical approach was used in 6 (42.9%) patients; 3 (21.4%) resections were gross total resections, while 11 (78.6%) were considered near-total or subtotal resections. Median interval from date of initial surgery to first radiographic evidence of recurrence was 1.55 years. Local recurrence occurred purely in the initial cystic component of the tumor extent in 2 (14.3%) patients, was predominantly cystic and extending inferiorly to the initial solid component in 2 (14.3%) patients, and arising from the solid tumor resection bed in 10 (71.4%) patients. <h3>Conclusion</h3> A significant proportion of craniopharyngiomas recur within the cystic component of the initial tumor without adjuvant therapy, supporting continued incorporation of both solid and cystic components of the pre-surgical tumor extent in radiation therapy treatment plans.