Search

Purpose: In this prospective study, we sought to compare the clinical utility of fluorodeoxyglucose PET/MRI, MRI, and PET/CT in the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma (OHSCC). Methods: We examined 198 consecutive patients with biopsy-proven OHSCC who agreed to receive chemoradiation. All patients underwent pretreatment PET/MRI and PET/CT on the same day. Patients were followed-up for a minimum of 12 months or until death. The McNemar's test and receiver-operating characteristic (ROC) curves were used to compare sensitivity/specificity and the diagnostic capabilities of PET/MRI, MRI, and PET/CT, respectively. Results: We identified 55 patients (27.7%) who had synchronous cancers and/or distant metastases (number of involved sites: 83). The results of site-based analysis revealed that the sensitivity of PET/MRI was 15.7% higher than that of MRI (73.5% versus 57.8%, p < 0.001) and 3.6% higher compared with PET/CT (73.5% versus 69.9%, p = 0.083), whereas the sensitivity of PET/CT was 12.1% higher than that of MRI (69.9% versus 57.8%, p = 0.012). On a patient-basis, ROC curve analysis demonstrated that PET/MRI yielded a greater area under curve than MRI (0.930 versus 0.905, p = 0.023). There were no significant differences in terms of diagnostic capability between MRI and PET/CT (0.905 versus 0.917, p = 0.469) and between PET/MRI and PET/CT (0.930 versus 0.917, p = 0.062). Conclusions: In our cohort, PET/MRI showed a significantly higher diagnostic capability than MRI and no significant difference compared with PET/CT for the detection of synchronous cancers or distant metastases in patients with OHSCC. [ABSTRACT FROM AUTHOR]

Objective: Clinical outcomes of patients with resected oral cavity squamous cell carcinoma (OCSCC) chiefly depend on the presence of specific clinicopathological risk factors (RFs). Here, we performed a combined analysis of FDG-PET, genetic markers, and clinicopathological RFs in an effort to improve prognostic stratification. Methods: We retrospectively reviewed the clinical records of 2036 consecutive patients with first primary OCSCC who underwent surgery between 1996 and 2016. Of them, 345 underwent ultra-deep targeted sequencing (UDTS, between 1996 and 2011) and 168 whole exome sequencing (WES, between 2007 and 2016). Preoperative FDG-PET imaging was performed in 1135 patients from 2001 to 2016. Complete data on FDG-PET, genetic markers, and clinicopathological RFs were available for 327 patients. Results: Using log-ranked tests based on 5-year disease-free survival (DFS), the optimal cutoff points for maximum standardized uptake values (SUV-max) of the primary tumor and neck metastatic nodes were 22.8 and 9.7, respectively. The 5-year DFS rates were as follows: SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7 (n = 77) versus SUVtumor-max < 22.8 and SUVnodal-max < 9.7 (n = 250), 32%/62%, P < 0.001; positive UDTS or WES gene panel (n = 64) versus negative (n = 263), 25%/62%, P < 0.001; pN3b (n = 165) versus pN1-2 (n = 162), 42%/68%, P < 0.001. On multivariate analyses, SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7, a positive UDTS/WES gene panel, and pN3b disease were identified as independent prognosticators for 5-year outcomes. Based on these variables, we devised a scoring system that identified four distinct prognostic groups. The 5-year rates for patients with a score from 0 to 3 were as follows: loco-regional control, 80%/67%/47%/24% (P < 0.001); distant metastases, 13%/23%/55%/92% (P < 0.001); DFS, 74%/58%/28%/7% (P < 0.001); and disease-specific survival, 80%/64%/35%/7% (P < 0.001) respectively. Conclusions: The combined assessment of tumor and nodal SUV-max, genetic markers, and pathological node status may refine the prognostic stratification of OCSCC patients. [ABSTRACT FROM AUTHOR]

Purpose: Both head and neck magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) play a crucial role in the staging of primary nasopharyngeal carcinoma (NPC). In this study, we sought to prospectively investigate the clinical utility of simultaneous whole-body 18F-FDG PET/MRI for primary staging of NPC patients.Methods: We examined 113 patients with histologically confirmed NPC who underwent pretreatment, simultaneous whole-body PET/MRI and PET/CT for primary tumor staging. The images obtained with the different imaging modalities were interpreted independently and compared with each other.Results: PET/MRI increased the accuracy of head and neck MRI for assessment of primary tumor extent in four patients via addition of FDG uptake information to increase the conspicuity of morphologically subtle lesions. PET/MR images were more discernible than PET/CT images for mapping tumor extension, especially intracranial invasion. Regarding the N staging assessment, the sensitivity of PET/MRI (99.5%) was higher than that of head and neck MRI (94.2%) and PET/CT (90.9%). PET/MRI was particularly useful for distinguishing retropharyngeal nodal metastasis from adjacent nasopharyngeal tumors. For distant metastasis evaluation, PET/MRI exhibited a similar sensitivity (90% vs. 86.7% vs. 83.3%), but higher positive predictive value (93.1% vs. 78.8% vs. 83.3%) than whole-body MRI and PET/CT, respectively.Conclusions: For tumor staging of NPC, simultaneous whole-body PET/MRI was more accurate than head and neck MRI and PET/CT, and may serve as a single-step staging modality. [ABSTRACT FROM AUTHOR]

Purpose: This single-center retrospective study of prospectively collected data was aimed at comparing the clinical outcomes of positron emission tomography/computed tomography (PET/CT) for patients with oral cavity squamous cell carcinoma (OSCC) with symptomatic recurrences identified by PET/CT imaging following adjuvant therapy (Group A) versus those of cases with asymptomatic recurrences diagnosed through periodic post-adjuvant therapy PET/CT surveillance (Group B). We also sought to establish the priority of salvage therapy in the two study groups. Methods: We identified 111 patients with advanced resected OSCC who developed recurrences following adjuvant therapy (51 in Group A and 60 in Group B). Histopathology served as the gold standard for recurrent lesions. The impact of post-adjuvant therapy PET/CT surveillance was examined with Kaplan-Meier curves and Cox proportional hazards regression models. Results: The 2-year DSS and OS rates were marginally or significantly higher in Group B than in Group A ( P = 0.073 and P = 0.025, respectively). Time-dependent ROC curve analysis demonstrated that the optimal cutoff values for time to positive PET/CT findings in relation to OS were 12 months for Group A and 9 months for Group B, respectively. Independent risk factors identified in multivariate analyses were used to devise two prognostic scoring systems for 2-year DSS and OS in each study group (all P < 0.001). Conclusions: Scheduled periodic PET/CT surveillance is a valuable tool for early detection of recurrent lesion(s) in asymptomatic OSCC patients who bear risk factors for disease recurrence. The presence of clinical symptoms and a short time to positive PET/CT findings were adverse prognostic factors for clinical outcome in patients with advanced OSCC. The priority of salvage therapy is discussed in each patient subgroup according to the devised prognostic scoring systems. [ABSTRACT FROM AUTHOR]

Background/Aim: We prospectively investigated the potential usefulness of PET using a new tracer targeting integrin αvβ3 (termed RGD-K5) in patients with head and neck cancer (HNC) undergoing definitive concurrent chemoradiotherapy (CCRT). Patients and Methods: Newly diagnosed patients with locally advanced HNC scheduled for definitive CCRT were eligible. RDG-K5 PET and FDG PET scans were performed at three different time points (baseline, 2 weeks, and 3 months post-treatment). Results: Nine patients completed all of the three scans, whereas two patients withdrew after two scans only. Uptake of both RGD-K5 and FDG generally decreased following CCRT. However, the observed decrease did not differ significantly between complete responders and non-responders. At 3 months post-treatment, the uptake of both RGD-K5 and FDG at the main tumors was significantly lower in those who achieved complete responses than in those with residual tumors. Conclusion: RGD-K5 PET has the potential to identify patients with incomplete responses to CCRT. [ABSTRACT FROM AUTHOR]

Purpose: Human papillomavirus type 16 (HPV-16) positivity is associated with favourable survival in oropharyngeal squamous cell carcinoma (OPSCC). We report here a study of the prognostic significance of F-FDG PET/CT functional parameters and HPV-16 infection in OPSCC patients. Methods: We retrospectively analysed 60 patients with stage III or IV OPSCC who had had a pretherapy F-FDG PET/CT scan and had completed concurrent chemoradiotherapy ( n = 58) or curative radiotherapy ( n = 2). All patients were followed up for ≥24 months or until death. We determined total lesion glycolysis (TLG) and the maximal standardized uptake values (SUV) of the primary tumour and neck lymph nodes from the pretherapy F-FDG PET/CT scan. Optimal cut-offs of the F-FDG PET/CT parameters were obtained by receiver operating characteristic (ROC) curve analyses. Pretherapy tumour biopsies were studied by polymerase chain reaction to determine HPV infection status. Results: The pretherapy tumour biopsies were positive for HPV-16 in 12 patients (20.0 %). Cox regression analyses revealed HPV-16 positivity and tumour TLG >135.3 g to be independently associated with overall survival ( p = 0.027 and 0.011, respectively). However, only tumour TLG >135.3 g was independently associated with progression-free survival, disease-free survival and locoregional control ( p = 0.011, 0.001 and 0.034, respectively). A scoring system was formulated to define distinct overall survival groups using tumour TLG and HPV-16 status. Patients positive for HPV-16 and with tumour TLG ≤135.3 g experienced better survival than those with tumour TLG >135.3 g and no HPV infection ( p = 0.001). Conclusion: Tumour TLG was an independent predictor of survival in patients with locally advanced OPSCC. A scoring system was developed and may serve as a risk stratification strategy for guiding therapy. [ABSTRACT FROM AUTHOR]

Purpose: Extracapsular spread (ECS) to the cervical lymph nodes is a major adverse prognostic factor in oral cavity squamous cell carcinoma (OSCC). We prospectively examined the value of FDG PET immediately before postoperative radiotherapy/concurrent chemoradiotherapy (pre-RT/CCRT PET) to detect residual/relapsing disease in the early postsurgical follow-up period in high-risk OSCC patients with ECS. Methods: We examined 183 high-risk OSCC patients with ECS who underwent preoperative FDG PET/CT for staging purposes. Of these patients, 29 underwent a second pre-RT/CCRT FDG PET/CT scan. The clinical utility of the second FDG PET/CT was examined using Kaplan-Meier curve analysis. Results: Patients who underwent the second FDG PET/CT scan had baseline clinicopathological characteristics similar to those who did not undergo a second scan. Of the patients who underwent the second scan, seven (24 %) had unexpected, newly discovered lesions. Five eventually died of the disease, and two had no evidence of recurrence after a change in RT field and dose. In an event-based analysis at 2 months, rates of neck control (6/29 vs. 6/154, p = 0.001), distant metastases (3/29 vs. 4/154, p = 0.046), and disease-free survival (7/29 vs. 10/154, p = 0.003) were significantly higher in patients who received a second PET scan than in those who did not. The second pre-RT/CCRT PET scan was of particular benefit for detecting new lesions in OSCC patients with both ECS and lymph node standardized uptake value (SUV) of ≥5.2 in the first PET scan. Conclusion: The present findings support the clinical value of pre-RT/CCRT FDG PET for defining treatment strategy in OSCC patients with both ECS and high nodal SUV, even when FDG PET had already been performed during the initial staging work-up. [ABSTRACT FROM AUTHOR]