Predicting response to radical (chemo)radiotherapy with circulating HPV DNA in locally advanced head and neck squamous carcinoma.

BACKGROUND: Following chemo-radiotherapy (CCRT) for human papilloma virus positive (HPV+) locally advanced head and neck cancer, patients frequently undergo unnecessary neck dissection (ND) and/or repeated biopsies for abnormal PET-CT, which causes significant morbidity. We assessed the role of circulating HPV DNA in identifying 'true' residual disease. METHODS: We prospectively recruited test (n=55) and validation (n=33) cohorts. HPV status was confirmed by E7 RT-PCR. We developed a novel amplicon-based next generation sequencing assay (HPV16-detect) to detect circulating HPV DNA. Circulating HPV DNA levels post-CCRT were correlated to disease response (PET-CT). RESULTS: In pre-CCRT plasma, HPV-detect demonstrated 100% sensitivity and 93% specificity, and 90% sensitivity and 100% specificity for the test (27 HPV+) and validation (20 HPV+) cohorts, respectively. Thirty-six out of 37 patients (test and validation cohort) with complete samples-set had negative HPV-detect at end of treatment. Six patients underwent ND (3) and repeat primary site biopsies (3) for positive PET-CT but had no viable tumour. One patient had positive HPV-detect and positive PET-CT and liver biopsy, indicating 100% agreement for HPV-detect and residual cancer. CONCLUSIONS: We demonstrate that HPV16-detect is a highly sensitive and specific test for identification of HPV DNA in plasma at diagnosis. HPV DNA post-treatment correlates with clinical response.

Evaluation of the role of 18FDG-PET/CT in radiotherapy target definition in patients with head and neck cancer.

BACKGROUND AND PURPOSE: As techniques for radiotherapy delivery have developed, increasingly accurate localisation of disease is demanded. Functional imaging, particularly PET and its fusion with anatomical modalities, such as PET/CT, promises to improve detection and characterisation of disease. This study evaluated the impact of (18)FDG-PET/CT on radiotherapy target volume definition in head and neck cancer (HNC). MATERIALS AND METHODS: The PET/CT scans of patients with HNC were used in a radiotherapy planning (RTP) study. The gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV) were defined conventionally and compared to those defined using the PET/CT. Data were reported as the median value with 95% confidence intervals. RESULTS: Eighteen patients were consented, 9 had known primary tumour site, 9 presented as unknown primary. In nine cases where the primary site was known, the combined primary and nodal GTV (GTVp+n) increased by a median of 6.1cm(3) (2.6, 12.2) or 78% (18, 313), p=0.008 with CTV increasing by a median of 10.1cm(3) (1.3, 30.6) or 4% (0, 13) p=0.012. In 9 cases of unknown primary the GTVp+n increased by a median 6.3 cm(3) (0.2, 15.7) or 61% (4, 210), p=0.012, with CTV increasing by a median 155.4 cm(3) (2.7, 281.7) or 95% (1, 137), p=0.008. CONCLUSION: (18)FDG-PET revealed disease lying outside the conventional target volume, either extending a known area or highlighting a previously unknown area of disease, including the primary tumour in 5 cases. We recommend PET/CT in the RTP of all cases of unknown primary. In patients with a known primary, although the change in volume was statistically significant the clinical impact is less clear. (18)FDG-PET can also show areas within the conventional target volume that are hypermetabolic which may be possible biological target volumes for dose escalation studies in the future.

The emerging potential of magnetic resonance imaging in personalizing radiotherapy for head and neck cancer: an oncologist's perspective.

Head and neck cancer (HNC) is a challenging tumour site for radiotherapy delivery owing to its complex anatomy and proximity to organs at risk (OARs) such as the spinal cord and optic apparatus. Despite significant advances in radiotherapy planning techniques, radiation-induced morbidities remain substantial. Further improvement would require high-quality imaging and tailored radiotherapy based on intratreatment response. For these reasons, the use of MRI in radiotherapy planning for HNC is rapidly gaining popularity. MRI provides superior soft-tissue contrast in comparison with CT, allowing better definition of the tumour and OARs. The lack of additional radiation exposure is another attractive feature for intratreatment monitoring. In addition, advanced MRI techniques such as diffusion-weighted, dynamic contrast-enhanced and intrinsic susceptibility-weighted MRI techniques are capable of characterizing tumour biology further by providing quantitative functional parameters such as tissue cellularity, vascular permeability/perfusion and hypoxia. These functional parameters are known to have radiobiological relevance, which potentially could guide treatment adaptation based on their changes prior to or during radiotherapy. In this article, we first present an overview of the applications of anatomical MRI sequences in head and neck radiotherapy, followed by the potentials and limitations of functional MRI sequences in personalizing therapy.

CHK1 Inhibition Radiosensitizes Head and Neck Cancers to Paclitaxel-Based Chemoradiotherapy.

Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer-related deaths, with increasingly more cases arising due to high-risk human papillomavirus (HPV) infection. Cisplatin-based chemoradiotherapy is a standard-of-care for locally advanced head and neck cancer but is frequently ineffective. Research into enhancing radiation responses as a means of improving treatment outcomes represents a high priority. Here, we evaluated a CHK1 inhibitor (CCT244747) as a radiosensitiser and investigated whether a mechanistically rational triple combination of radiation/paclitaxel/CHK1 inhibitor delivered according to an optimized schedule would provide added benefit. CCT244747 abrogated radiation-induced G2 arrest in the p53-deficient HNSCC cell lines, HN4 and HN5, causing cells to enter mitosis with unrepaired DNA damage. The addition of paclitaxel further increased cell kill and significantly reduced tumor growth in an HN5 xenograft model. Importantly, a lower dose of paclitaxel could be used when CCT244747 was included, therefore potentially limiting toxicity. Triple therapy reduced the expression of several markers of radioresistance. Moreover, the more radioresistant HN5 cell line exhibited greater radiation-mediated CHK1 activation and was more sensitive to triple therapy than HN4 cells. We analyzed CHK1 expression in a panel of head and neck tumors and observed that primary tumors from HPV(+) patients, who went on to recur postradiotherapy, exhibited significantly stronger expression of total, and activated CHK1. CHK1 may serve as a biomarker for identifying tumors likely to recur and, therefore, patients who may benefit from concomitant treatment with a CHK1 inhibitor and paclitaxel during radiotherapy. Clinical translation of this strategy is under development. Mol Cancer Ther; 15(9); 2042-54. ©2016 AACR.

Evaluation of the Risk of Grade 3 Oral and Pharyngeal Dysphagia Using Atlas-Based Method and Multivariate Analyses of Individual Patient Dose Distributions.

PURPOSE: The study aimed to apply the atlas of complication incidence (ACI) method to patients receiving radical treatment for head and neck squamous cell carcinomas (HNSCC), to generate constraints based on dose-volume histograms (DVHs), and to identify clinical and dosimetric parameters that predict the risk of grade 3 oral mucositis (g3OM) and pharyngeal dysphagia (g3PD). METHODS AND MATERIALS: Oral and pharyngeal mucosal DVHs were generated for 253 patients who received radiation (RT) or chemoradiation (CRT). They were used to produce ACI for g3OM and g3PD. Multivariate analysis (MVA) of the effect of dosimetry, clinical, and patient-related variables was performed using logistic regression and bootstrapping. Receiver operating curve (ROC) analysis was also performed, and the Youden index was used to find volume constraints that discriminated between volumes that predicted for toxicity. RESULTS: We derived statistically significant dose-volume constraints for g3OM over the range v28 to v70. Only 3 statistically significant constraints were derived for g3PD v67, v68, and v69. On MVA, mean dose to the oral mucosa predicted for g3OM and concomitant chemotherapy and mean dose to the inferior constrictor (IC) predicted for g3PD. CONCLUSIONS: We have used the ACI method to evaluate incidences of g3OM and g3PD and ROC analysis to generate constraints to predict g3OM and g3PD derived from entire individual patient DVHs. On MVA, the strongest predictors were radiation dose (for g3OM) and concomitant chemotherapy (for g3PD).

Characterizing Heterogeneity within Head and Neck Lesions Using Cluster Analysis of Multi-Parametric MRI Data.

PURPOSE: To describe a methodology, based on cluster analysis, to partition multi-parametric functional imaging data into groups (or clusters) of similar functional characteristics, with the aim of characterizing functional heterogeneity within head and neck tumour volumes. To evaluate the performance of the proposed approach on a set of longitudinal MRI data, analysing the evolution of the obtained sub-sets with treatment. MATERIAL AND METHODS: The cluster analysis workflow was applied to a combination of dynamic contrast-enhanced and diffusion-weighted imaging MRI data from a cohort of squamous cell carcinoma of the head and neck patients. Cumulative distributions of voxels, containing pre and post-treatment data and including both primary tumours and lymph nodes, were partitioned into k clusters (k = 2, 3 or 4). Principal component analysis and cluster validation were employed to investigate data composition and to independently determine the optimal number of clusters. The evolution of the resulting sub-regions with induction chemotherapy treatment was assessed relative to the number of clusters. RESULTS: The clustering algorithm was able to separate clusters which significantly reduced in voxel number following induction chemotherapy from clusters with a non-significant reduction. Partitioning with the optimal number of clusters (k = 4), determined with cluster validation, produced the best separation between reducing and non-reducing clusters. CONCLUSION: The proposed methodology was able to identify tumour sub-regions with distinct functional properties, independently separating clusters which were affected differently by treatment. This work demonstrates that unsupervised cluster analysis, with no prior knowledge of the data, can be employed to provide a multi-parametric characterization of functional heterogeneity within tumour volumes.

Multiple cervical lymph node involvement and extra-capsular extension predict for contralateral nodal recurrence after ipsilateral radiotherapy for squamous cell carcinoma of the tonsil.

BACKGROUND: Ipsilateral radiotherapy is an established technique for treating well-lateralised tonsillar tumours. Concerns exist regarding the risk of contralateral nodal failure, particularly in patients with ipsilateral nodal involvement at presentation. In this study, we retrospectively reviewed the clinical outcomes of patients treated with ipsilateral radiotherapy aiming to identify factors that predispose to a higher risk of contralateral nodal recurrence. METHODS: Retrospective case note review of all patients with tonsillar cancer who were treated using ipsilateral radiotherapy between September 1995 and September 2011 was performed. Demographics, T and N stage, involvement of soft palate and/or tongue base, presence of extra-capsular spread (ECS) and treatment details were recorded. Kaplan-Meier curves for treatment outcomes were generated. RESULTS: A total of 136 patients were identified. Median follow-up was 4.2years. Twelve (9%) patients had loco-regional recurrence. Eight patients (6%) had contralateral recurrence. N2b disease, ECS and number of pack-years of smoking were associated with contralateral nodal recurrence. Five-year overall survival was 89%, loco-regional disease-free survival 90%, disease-free survival 86% and distal recurrence-free survival 96%. CONCLUSION: N2b disease, ECS and a greater than 10 pack-year smoking history are risk factors for contralateral nodal recurrence in well-lateralised tonsillar cancers. Prophylactic irradiation of the contralateral neck should be recommended in this group of patients.

Changes in functional imaging parameters following induction chemotherapy have important implications for individualised patient-based treatment regimens for advanced head and neck cancer.

BACKGROUND: When induction chemotherapy (IC) is used prior to chemoradiotherapy (CRT) in head and neck cancer (HNC), functional imaging (FI) may inform adaptation of treatment plans with the aim of optimising outcomes. Understanding the impact of IC on FI parameters is, therefore, essential. PURPOSE: To prospectively evaluate the feasibility of acquiring serial FI ((18)F-FDG-PET, diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI) and its role in defining individualised treatment regimens following IC in HNC. METHODS AND MATERIALS: Ten patients with stage III and IV HNC underwent conventional (CT and MRI) and functional (DW, DCE-MRI and (18)F-FDG-PET/CT) imaging at baseline and following two cycles of IC prior to definitive CRT. RESULTS: One patient withdrew due to claustrophobia. Seven out of nine patients had a complete metabolic response to IC on (18)F-FDG-PET imaging. DCE-MRI showed a significant fall in transfer constant (K(trans)) (0.209 vs 0.129 min(-1)P<0.01) and integrated area under gadolinium curve at 60s (IAUGC6O) (18.4 vs 11.9 mmol/min, P<0.01) and DW-MRI a rise in ADC (0.89 vs 1.06 × 10(-3) mm(2)/s, P<0.01) following IC. CONCLUSIONS: Acquiring FI sequences is feasible in HNC. There are marked changes in FI parameters following IC which may guide adaptation of individualised treatment regimens.

PET/CT in Radiotherapy Planning for Head and Neck Cancer.

The use of PET/CT as an adjunct in radiotherapy planning is an attractive option in head and neck cancer (HNC) for several reasons. First, with potentially better identification of the disease extent, i.e., staging, the risk of geographical miss of radiation delivery to the gross tumor volume is reduced. Second, in characterizing the biological behavior of the disease for example, areas of hypoxia, rich or poor vascularity, or high cell proliferation, PET/CT can identify biological target volumes either for escalation of radiation dose or to predict the requirement for the addition of a radiosensitizer or alternative treatment strategies. (18)F-FDG is the most common tracer used in oncology studies, but many other tracers have been investigated with several entering clinical practice, although these remain predominantly in the research domain in HNC.

Prospective intra-patient evaluation of a shoulder retraction device for radiotherapy in head and neck cancer.

Irradiation of tumors in the larynx and pharynx is often technically challenging in patients with a short neck or high shoulders. Shoulder retraction devices can sometimes resolve this problem and allow irradiation via lateral beam directions. This study aimed to measure the proportion of patients who would benefit from such an approach and to quantify the magnitude of the benefit obtained. Twenty patients were studied. Simulator images were obtained before and after intervention. The additional exposure of the cervical spine was measured. Patient comfort and acceptability were assessed with a questionnaire. Improvement of exposure of the cervical spine was observed in 80% of patients. In 20%, there was either no difference or the position was worse. Shoulder retraction exposed a mean of 8.4-10.2 mm more of the cervical spine. Patients in general reported the device as comfortable. The use of a shoulder retraction device produced clinically significant improvements in exposure of the tissues of the cervical spine and neck and should be considered in patients being irradiated for tumors arising in the larynx or hypopharynx.

Dose-response analysis of acute oral mucositis and pharyngeal dysphagia in patients receiving induction chemotherapy followed by concomitant chemo-IMRT for head and neck cancer.

Dose-response curves (DRCs) and the quantitative parameters describing these curves were generated for grade 3 oral mucositis and dysphagia in 144 patients using individual patient DVHs. Curve fits to the oral mucositis clinical data yielded parameter values of mean dose in 2 Gy equivalent, MD(50) = 51 Gy (95% CI 40-61), slope of the curve, k = 1(95% CI 0.6-1.5). R(2) value for the goodness of fit was 0.80. Fits to the grade 3 dysphagia clinical data yielded parameter values of MD(50) = 44.5 Gy (95% CI 36-53), k = 2.6 (95% CI 0.8-4.5). R(2) value for the goodness of fit was 0.65. This is the first study to derive DRCs in patients receiving induction chemotherapy followed by chemo-radiation (IC-C-IMRT) for head and neck cancer. The dose-response model described in this study could be useful for comparing acute mucositis rates for different dose-fractionation schedules when using IMRT for head and neck cancer.

Analysis of the efficacy and toxicity of sorafenib in thyroid cancer: a phase II study in a UK based population.

AIM: To evaluate the tolerability and efficacy of sorafenib in patients with thyroid carcinoma. METHODS: Patients with progressive locally advanced/metastatic medullary thyroid carcinoma (MTC), or differentiated thyroid carcinoma (DTC) with non-radioiodine-avid disease, were treated with sorafenib 400 mg twice daily until disease progression. The primary endpoint was the radiological response rate (RR) at 6 months. Secondary endpoints were RR at 3, 9 and 12 months, biochemical responses, toxicity, biomarker analyses and progression free and overall survival (OS). RESULTS: A total of 34 patients were recruited to the study (15 medullary and 19 differentiated). After 6 months, the RR rate was 15% and a further 74% of patients achieved stable disease in the first 6 months. After 12 months of treatment, the RR was 21%. In the MTC patients, the RR at 12 months was 25% and OS was 100%. In DTC patients corresponding rates were 18 and 79% respectively. Median overall and progression-free survival points were not reached at 19 months. Commonest adverse events included hand-foot syndrome, other skin toxicities, diarrhoea and alopecia. Dose reduction was required in 79% patients. Median time on treatment was 16.5 months. CONCLUSION: This study demonstrates that sorafenib is tolerable at reduced doses over prolonged periods of time in patients with thyroid cancer. Sorafenib leads to radiological and biochemical stabilisation of disease in the majority of these patients despite dose reductions.

Characteristics of response of oral and pharyngeal mucosa in patients receiving chemo-IMRT for head and neck cancer using hypofractionated accelerated radiotherapy.

PURPOSE: This study describes the acute response of oral and pharyngeal mucosa to chemo-IMRT schedules using different doses per fraction. MATERIALS AND METHODS: Patients, treated in prospective trials of concomitant chemo-IMRT with 2.17 Gy, 2.25 Gy and 2.4 Gy per fraction and identical dose of cisplatin, were included in this study. Acute toxicity was recorded prospectively using the CTCAE v2.0. We describe the incidence and prevalence of grade 3 oral mucositis and dysphagia over time and report the influence of overall treatment time (OTT). The association between the lengths of pharyngeal mucosa receiving 50 Gy (L50) and 60 Gy (L60) and grade 3 dysphagia was tested. RESULTS: The incidence and the peak prevalence of grade 3 dysphagia were significantly higher in patients receiving 2.4 Gy per fraction. The peak prevalence of grade 3 dysphagia was higher and the recovery was slower in patients with lower OTT (median 38 days vs. 42 days) treatment. There was a significant correlation between L50, L60 and grade 3 dysphagia. A L50 and L60 greater than 8 cm resulted in greater than 60% and 70% incidence of grade 3 dysphagia, respectively. CONCLUSION: The length of pharyngeal mucosa receiving doses close to the prescription dose correlates with grade 3 dysphagia. It was observed that incidence of grade 3 dysphagia was lower and recovery from it was quicker in patients with greater OTT.