Is a total dose of 54 Gy with radiochemotherapy sufficient for treatment of intermediate-risk volumes in nasopharyngeal cancer?
STRAHLENTHERAPIE UND ONKOLOGIE, vol.200, no.5, pp.409-417, 2024 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 200 Issue: 5
- Publication Date: 2024
- Doi Number: 10.1007/s00066-023-02186-3
- Journal Name: STRAHLENTHERAPIE UND ONKOLOGIE
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CINAHL, MEDLINE
- Page Numbers: pp.409-417
- Keywords: Intermediate-risk volume, Nasopharyngeal carcinoma, Radiotherapy, Radiotherapy dose, Recurrence
- Istanbul University-Cerrahpasa Affiliated: Yes
Abstract
BackgroundThe mainstay treatment of nasopharyngeal cancer (NPC) is radiation therapy (RT). The doses and volumes may differ from center to center. Most studies and guidelines recommend a total dose of 60 Gy for elective nodal and peritumoral volume treatment. This retrospective analysis aimed to analyze whether a dose reduction to 54 Gy to this volume would be associated with a higher risk of recurrence.MethodsA total of 111 patients treated by intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy were retrospectively analyzed. The recurrent tumor volume was classified as "in field" if 95% of the recurrent volume was inside the 95% isodose, as "marginal" if 20-95% of the recurrence was inside the 95% isodose, or as "outside" if less than 20% of the recurrence was inside the 95% isodose.ResultsMedian follow-up was 67 months (range 6-142). The 2- and 5-year overall survival (OS) rates were 88.6% and 70%, respectively. The 2-year locoregional control (LRC), disease-free survival (DFS), and distant metastasis-free survival (DMFS) were 93.3%, 89.3%, and 87.4%, and the 5-year LRC, DFS, and DMFS were 86.8%, 74%, and 81.1%, respectively. Ten patients (9%) had a local and or regional recurrence. Half of the patients with locoregional failure had in-field recurrences. For primary tumor, there was no recurrence in the volume of 54 Gy. For regional lymph node volume, recurrence was detected in two (1.8%) patients in the volume of 54 Gy.ConclusionThese retrospective data suggest that a dose reduction may be possible for intermediate-risk volumes, especially for the primary site.