Introduction: Laser interstitial thermal therapy (LITT) is an intriguing, minimally invasive treatment modality for many neurosurgical pathologies, including tumors, radiation necrosis, chronic pain, and epilepsy. Reported complications are typically recognized in the early postoperative period, and include neurologic deficit, hemorrhage, edema and infection.
Methods: Here, we discuss a series of two interesting cases of late-onset cyst formation after LITT, a complication that, to our knowledge, has not yet been reported in the literature.
Results: The first case is a 59 year-old female treated with LITT for an epileptogenic cavernoma caused by stereotactic radiosurgery for an AVM refractory to embolization. This patient tolerated the procedure well and had unremarkable follow up until 19 months after the procedure, when cyst formation was noted on surveillance MRI. At this time, the cyst was 1.3cm in greatest axial dimension. At 28 months, the cyst expanded to 2.1cm in greatest dimension and was symptomatic requiring resection. The cyst was found to contain xanthochromic fluid, and surgical pathology was negative for tumor or AVM recurrence.
The second case is a 53 year-old female who received LITT for infield recurrence of a breast metastasis after resection with adjuvant gamma knife and chemotherapy. This patient also tolerated the procedure well and had a stable ablation cavity with solid and cystic components, which measured 1.6cm at greatest axial dimension. At 29 months, the cystic portion extended outside of the original cavity and expanded significantly, at that time measuring 3.0cm in greatest axial dimension.
Conclusions: These cases emphasize the importance of continued follow up in LITT patients despite radiologic and symptomatic stability, as well as the need for further study of the long term outcomes of LITT.
Patient Care: These cases highlight the importance of long-term follow up in LITT patients, so that late-onset complications, such as the cysts that we describe, can be recognized early and intervened on, if necessary.
Learning Objectives: By the conclusion of this session, participants should be able to 1) Describe the pathologies treated with and known complications of LITT, 2) Discuss cyst formation as a long-term outcome of LITT, 3) Recognize the importance of further study of long-term outcomes of LITT