Gamma Knife Radiosurgery Using Co-Registration with PET-CT and MRI for Recurrent Nasopharyngeal Carcinoma with Previous Radiotherapy : A Single Center 14-Year Experience

Chaejin Lee; Seong-Hyun Park; Sang-Youl Yoon; Ki-Su Park; Jeong-Hyun Hwang; Sung-Kyoo Hwang

doi:10.3340/jkns.2019.0011

Gamma Knife Radiosurgery Using Co-Registration with PET-CT and MRI for Recurrent Nasopharyngeal Carcinoma with Previous Radiotherapy : A Single Center 14-Year Experience

J Korean Neurosurg Soc. 2020 May;63(3):397-405. doi: 10.3340/jkns.2019.0011. Epub 2019 Nov 28.

Authors

Chaejin Lee^{1

2}, Seong-Hyun Park^{1

2}, Sang-Youl Yoon^{1

2}, Ki-Su Park^{1

2}, Jeong-Hyun Hwang^{1

2}, Sung-Kyoo Hwang^{1

2}

Affiliations

¹ Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, Korea.
² Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea.

Abstract

Objective: We retrospectively evaluated the efficacy of Gamma Knife radiosurgery (GKS) for recurrent nasopharyngeal carcinoma (NPC) in patients who previously underwent radiotherapy, and analyzed the treatment outcomes over 14 years.

Methods: Ten patients with recurrent NPC who had previously received radiotherapy underwent stereotactic radiosurgery using a Gamma Knife® (Elekta Inc, Atlanta, GA, USA) between 2005 and 2018. The median target volume was 8.2 cm3 (range, 1.7-17.8), and the median radiation dose to the target was 18 Gy (range, 12-30). The median follow-up period was 18 months (range, 6-76 months). Overall and local failure-free survival rates were determined using the Kaplan-Meier method.

Results: The NPCs recurred at the primary cancer site in seven patients (70%), as distant brain metastasis in two (20%), and as an extension into brain in one (10%). The recurrent tumors in seven of the 10 patients (70%) were found on the routine follow-up imaging studies. Two patients presented with headache and one with facial pain. Local failure after GKS occurred in five patients (50%) : two of whom died eight and 6 months after GKS, respectively. No adverse radiation effects were noted after GKS. The 1- and 3-year overall survival rates after GKS were 90% and 77%, respectively. The local failure-free survival rates at 6 months, 1 year, and 3 years after GKS were 80%, 48%, and 32%, respectively. The median interval from GKS to local failure was 8 months (range, 6-12). Univariate analysis revealed that using co-registration with positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) was associated with a lower local failure rate of recurrent NPC (p=0.027).

Conclusion: GKS is an acceptable salvage treatment option for patients with recurrent NPC who previously received radiation therapy. PET-CT and MRI co-registration for dose planning can help achieve local control of recurrent NPC.

Keywords: Nasopharyngeal carcinoma; Positron emission tomography computed tomography; Radiosurgery.