FDG-PET/CT in the Assessment of Treatment Response after Oncologic Treatment of Head and Neck Squamous Cell Carcinoma

Abstract

BACKGROUNDIn many centers, 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is used to monitor treatment response after definitive (chemo)radiotherapy [(C)RT] for head and neck squamous cell carcinoma (HNSCC), but its usefulness remains somewhat controversial. We aimed at assessing the accuracy of FDG-PET/CT in detecting residual disease after (C)RT.METHODAll HNSCC patients with FDG-PET/CT performed to assess treatment response 10–18 weeks after definitive (C)RT at our institution during 2008–2010 were included. The patient charts were reviewed for FDG-PET/CT findings, histopathologic findings, and follow-up data. The median follow-up time for FDG-PET/CT negative patients was 26 months.RESULTSEighty-eight eligible patients were identified. The stage distribution was as follows: I, n = 1; II, n = 15; III, n = 17; IV, n = 55. The negative predictive value, positive predictive value, specificity, sensitivity, and accuracy of FDG-PET/CT in detecting residual disease were 87%, 81%, 94%, 65%, and 85%, respectively. The corresponding specific figures for the primary tumor site were 91%, 71%, 94%, 59%, and 86% and for the neck 93%, 100%, 100%, 75%, and 94%, respectively.CONCLUSIONSIn patients who have received definitive (C)RT for HNSCC, post-treatment FDG-PET/CT has good potential to guide clinical decision-making. Patients with negative scan can safely be followed up clinically only, while positive scan necessitates tissue biopsies or a neck dissection to rule out residual disease.

Temporal patterns of 18F‐fluorodeoxyglucose positron emission tomography/computed tomography sinonasal uptake after treatment of sinonasal malignancy

“…Reports of improved diagnostic accuracy when PET/CT is employed for HNSCC at or after this time-point reflect the preceding resolution or reduction in treatmentinduced inflammation. 9,11,12 In the current study's patient cohort, which included exclusively sinonasal sites of malignancy, the period of treatment-induced inflammation endured for up to twice the duration (ࣙ 5 months) observed in deep tissue sites of the head and neck. These findings concur with clinical experience that suggests the sinonasal skull base responds to oncologic treatment in a manner that is distinct from other head and neck subsites.…”

“…8 The reduced accuracy of PET/CT in the early posttreatment setting has largely been attributed to its limited ability to distinguish residual disease from treatment-induced inflammatory changes. 9,10 This inherent weakness of PET/CT has prompted considerable interest within the head and neck literature to determine the optimal time window for PET/CT in the evaluation of treatment response. Several studies, including 2 systematic reviews with meta-analyses, have identified 10 to 12 weeks posttreatment as the ideal time-point for improved diagnostic accuracy of PET or PET/CT, insofar as differentiating persistent viable disease from posttreatment inflammation for deep tissue sites of the head and neck.…”

“…Several studies, including 2 systematic reviews with meta-analyses, have identified 10 to 12 weeks posttreatment as the ideal time-point for improved diagnostic accuracy of PET or PET/CT, insofar as differentiating persistent viable disease from posttreatment inflammation for deep tissue sites of the head and neck. 9,11,12 Employment of PET/CT in the surveillance of previously treated malignancies of the skull base has revealed that posttreatment mucosal inflammation of the sinonasal skull base may persist for a longer period of time compared with deep tissue sites of the head and neck. 8 This predisposition for intensified and prolonged inflammation after treatment appears to be physiologically plausible given the long-term exposure of the sinonasal skull base mucosal lining to extracorporeal irritants and microbial factors in addition to treatment-related disruption of mucociliary function, [13][14][15][16] a critical natural defense of the paranasal sinuses.…”

Potential Role of PET/MRI for Imaging Metastatic Lymph Nodes in Head and Neck Cancer

“…Previous studies have shown that posttreatment PET assessment can be used to avoid unnecessary planned neck dissection even in the presence of nodal abnormalities on CT if they become negative on PET [60, 61]. Keski-Säntti et al [62] reported that PET/CT conducted about 3 months after therapy has sensitivity, specificity, positive predictive value (PPV), and NPV of 59%, 94%, 71%, and 91% for detecting residual disease in the primary sites, and 95%, 100%, 100%, and 93% in the nodes, respectively. Recently, Anderson et al [63] used SUV measurements at 60, 90, and 120 minutes and found that change of maximum SUV slope after 90 minutes more accurately identified non-recurrence in positive or equivocal sites than using SUV at one point.…”

Advancing theranostics with tumor‐targeting peptides for precision otolaryngology

“…18 F-FDG PET is used for the diagnosis, staging, and restaging of HNSCC patients. Unfortunately 18 F-FDG PET has a false positive rate of 23%–30% in HNSCC patients, 7 , 8 , 9 , 10 which may necessitate further diagnostic evaluation and tissue sampling as well as potentially delaying therapy. These current limitations and the critical need for improved diagnostic, quantitative and prognostic stratification of HNSCC patients before, during and after definitive therapy are recognized by the interdisciplinary treatment team.…”