Recurrences after intensity modulated radiotherapy for head and neck squamous cell carcinoma more likely to originate from regions with high baseline [18F]-FDG uptake

Abstract

Background and Purpose To analyze the recurrence pattern in relation to target volumes and 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography in head and neck squamous cell carcinoma (HNSCC) patients treated with definitive chemoradiation. Material and Methods 520 patients received radiotherapy for HNSCC from 2005–2009. Among 100 patients achieving complete clinical response and a later recurrence, 39 patients with 48 loco-regional failures had a recurrence CT scan before any salvage therapy. The estimated point of origin of each recurrence was transferred to the planning CT by deformable image co-registration. The recurrence position was then related to the delineated target volumes and iso-SUV-contours relative to the maximum standard uptake value (SUV). We defined the recurrence density as the total number of recurrences in a sub-volume divided by the sum of that volume for all patients. Results 54% (95% CI 37–69%) of recurrences originated inside the FDG-positive volume and 96% (95% CI 86–99%) in the high dose region. Recurrence density was significantly higher in the central target volumes (P<0.0001) and increased with increasing FDG avidity (P=0.036). Conclusions The detailed pattern-of-failure data analysis suggest that most recurrences occur in the FDG PET positive areas or the solid tumor.

18F-Fdg-PET-guided Planning and Re-Planning (Adaptive) Radiotherapy in Head and Neck Cancer: Current State of Art

“…Moreover, the delineation of GTV and standardized uptake value (SUV) levels evaluation allows the design of dose escalation strategies, improving the possibility to identify tumor subvolumes with higher risk of recurrences (17,(47)(48)(49)(50). 18 F-FDG PET may be useful even as a prognostic factor due to the ability to early detect tumor recurrences (15)(16)(17)(18)(51)(52)(53)(54).…”

The promise of multiparametric imaging in oncology: how do we move forward?

“…Such studies allow correlation of imaging features with the patient or tumour outcome (e.g. recurrence location) using follow-up imaging of various lesions [15][16][17][18]. Another imaging approach is to validate the imaging characteristics with biological properties in the surgical specimen [19][20][21][22].…”

Visualization and quantification of tumour biology for personalized radiotherapy

“…Small studies testing temporal stability of hypoxia in NSCLC have so far found inconclusive results. Some studies have observed stable hypoxia [39,40], whereas others have reported a decrease in hypoxia [26,41], or a mix of stable and dynamic hypoxia [42]. Lin et al [43] showed in head and neck cancer that when there is a spatial shift, dose painting of the initial subvolume still results in improved equivalent uniform dose on a later scan.…”

“…FDG PET imaging is widely used to aid target delineation. Adding this functional imaging modality has shown to improve target definition, over anatomical imaging alone, in several tumour types [42,43].…”

“…It is likely that tumour heterogeneity affects radioresistance. If given a uniform dose throughout the tumour, local recurrences have shown to arise from small radioresistant niches [41,42]. Increasing the total radiotherapy dose to the tumour could theoretically increase the tumour control probability and is the safest approach if no information on radioresistance is available, however, the dose escalation that can be achieved is often limited by the healthy organs surrounding the tumour.…”