Abstract
Background To identify the radio-resistant subvolumes in pretreatment FDG-PET by mapping the spatial location of the origin of tumor recurrence after IMRT for head-and-neck squamous cell cancer to the pretreatment FDG-PET/CT. Methods Patients with local/regional recurrence after IMRT with available FDG-PET/CT and post-failure CT were included. For each patient, both pre-therapy PET/CT and recurrence CT were co-registered with the planning CT (pCT). A 4-mm radius was added to the centroid of mapped recurrence growth target volumes (rGTV's) to create recurrence nidus-volumes (NVs). The overlap between boost-tumor-volumes (BTV) representing different SUV thresholds/margins combinations and NVs was measured. Results Forty-seven patients were eligible. Forty-two (89.4%) had type A central high dose failure. Twenty-six (48%) of type A rGTVs were at the primary site and 28 (52%) were at the nodal site. The mean dose of type A rGTVs was 71 Gy. BTV consisting of 50% of the maximum SUV plus 10 mm margin was the best subvolume for dose boosting due to high coverage of primary site NVs (92.3%), low average relative volume to CTV1 (41%), and least average percent voxels outside CTV1 (19%). Conclusions The majority of loco-regional recurrences originate in the regions of central-high-dose. When correlated with pretreatment FDG-PET, the majority of recurrences originated in an area that would be covered by additional 10 mm margin on the volume of 50% of the maximum FDG uptake.
Original language | English (US) |
---|---|
Pages (from-to) | 248-255 |
Number of pages | 8 |
Journal | Radiotherapy and Oncology |
Volume | 124 |
Issue number | 2 |
DOIs | |
State | Published - Aug 2017 |
Keywords
- Biological target volume
- Dose escalation
- FDG-PET
- Head and neck cancer
- Patterns of failure
ASJC Scopus subject areas
- Hematology
- Oncology
- Radiology Nuclear Medicine and imaging