Elective Management of the Neck in Parotid Tumours.

AIMS: Management of the clinically node-negative (cN0) neck for parotid tumours remains controversial. Options include observation, elective neck dissection (END) or elective nodal irradiation (ENI). We reviewed the evidence for ENI on a background of current practice among UK clinical oncologists. MATERIALS AND METHODS: We carried out a systematic search of PubMed between 1 January 1980 and 31 December 2016. Articles on patients treated with parotidectomy and either END or ENI, and studies on nodal patterns of disease, were included. UK clinical oncologists were asked to complete an online questionnaire regarding their use of neck radiotherapy in this setting. RESULTS: From 96 references, 20 studies met the inclusion criteria: 11 reported on END, five on ENI and two on both. Eight studies reported on nodal patterns of disease. The prevalence of occult nodal metastases after END ranged from 0 to 45%. Five year locoregional control was variable (range 64-100%). For ENI, 5 year locoregional control varied from 74 to 100%. High-grade and T3/T4 tumours were factors for nodal relapse after END or ENI, which most commonly occurred in levels I-III. For the survey, 33/50 (66%) of cancer centres responded. Fourteen (42%) centres had guidelines for ENI. Most centres considered high-grade tumours (96%), T3/T4 disease (80%) and lymphovascular invasion (88%) as indications for ENI. Twelve centres (36%) irradiated levels Ib-IV electively; the remaining centres treated other various combinations of nodal levels. CONCLUSION: There is heterogeneity in the use and indications for ENI in the UK. ENI is a reasonable alternative to END as elective management for the cN0 neck in patients with high-grade tumours or T3/T4 disease. The elective clinical target volume should at least encompass nodal levels I-III.

Assessment of Upfront Selection Criteria to Prioritise Patients for Breath-hold Left-sided Breast Radiotherapy.

AIMS: Deep inspiratory breath-hold (DIBH) techniques for left breast and chest wall radiotherapy can reduce cardiac dose. We investigated the use of 'upfront selection' criteria for DIBH based on tumour bed position and whether cardiac shielding was used. MATERIALS AND METHODS: Four methods of selecting patients for DIBH were assessed retrospectively in a cohort of left breast and chest wall treatments. These were: (1) free breathing scan on all patients, selecting DIBH treatment for those with a predicted mean heart dose ≥3 Gy; (2) selective DIBH for those with maximum heart depth (MHD) on free breathing scan ≥1 cm; (3) use of an 'upfront selection process' using tumour bed position as initial selection and measurement of MHD on those not selected upfront; (4) DIBH on all. The methods were assessed on predicted mean heart dose, proportion needing two scans, sensitivity, specificity and the positive and negative predictive values. These were compared with method (1) as the gold standard. RESULTS: In total 134 cases were analysed. The predicted mean heart dose in free breathing was ≥3 Gy in 28 (20.9%). Therefore, applying method (1), 28/134 (20.9%) would be selected for DIBH treatment. Applying method (2), 66/134 (49.2%) would be selected for DIBH treatment, all requiring two scans. Of these, 40/66 (60.6%) would receive < 3 Gy in free breathing so are over-selected; 2/68 (2.9%) would have received >3 Gy in free breathing so failed to be selected. Selection using method (3) was similar to method (2), but only five patients required two planning scans; 61/134 (45.5%) cases would be selected for DIBH upfront and 5/134 (3.7%) after initial free breathing scan; 42/66 (63.6%) of those selected for DIBH treatment would receive <3 Gy in free breathing and 4/68 not selected (6%) would receive >3 Gy in free breathing. For methods (2) and (3) most patients not selected for DIBH would have had a mean heart dose of ≤3 Gy (64/68, 90%). Using method (3), 86% (95% confidence interval 67-96%) of patients with a mean heart dose >3 Gy would be selected for DIBH treatment. The estimated mean and standard error for the area under the receiver operator characteristic curve for MHD as a predictor for mean heart dose was 0.85 (0.03). CONCLUSION: This study supports the use of proposed an 'upfront selection process' as a means of selecting patients for treatment with DIBH and avoiding two radiotherapy planning scans. Calculation of MHD can be used as a surrogate for mean heart dose in the selection of cases for DIBH.

Standardisation of Target Volume Delineation for Carotid-sparing Intensity-modulated Radiotherapy in Early Glottis Cancer.

AIMS: Recently, carotid-sparing intensity-modulated radiotherapy (IMRT) for early laryngeal glottis (T1/T2N0M0) cancer has generated interest in the hope of avoiding long-term carotid toxicity, as well as concerns relating to geographical misses and long-term normal tissue toxicity. The aim of this review was to summarise the current literature on carotid-sparing IMRT for early glottis cancer, with particular focus on definitions of target volumes and the carotid arteries as organs at risk. In addition, we make suggestions for standardisation of these structures, dose constraints and dose reporting. MATERIALS AND METHODS: From 73 references, 16 articles met the criteria for inclusion in this systematic review. These papers described two case reports, 11 planning studies and three prospective studies. RESULTS: There was variation in all target volume definitions with no clear consensus. The greatest variability was in clinical target volume definition. Carotid artery and spinal cord delineation were not always defined and most studies did not use a carotid artery constraint. Of the eight studies that reported carotid artery delineation, no two studies delineated the same length of carotid artery, yet most studies reported mean doses. Most studies used IMRT with three to seven fields. Five studies used arc therapy and two studies used tomotherapy. CONCLUSION: This review highlights a lack of consensus in target volume definitions in carotid-sparing IMRT. Ultimately, long-term prospective data are required to show the benefit of carotid-sparing IMRT. Pooled data will prove useful as most studies will report on small numbers of patients. Therefore, adopting a consensus now on target volume definition, dose constraints and dose reporting will be crucial.

Total Mucosal Irradiation with Intensity-modulated Radiotherapy in Patients with Head and Neck Carcinoma of Unknown Primary: A Pooled Analysis of Two Prospective Studies.

AIMS: To determine the clinical outcomes of an intensity-modulated radiotherapy technique for total mucosal irradiation (TM-IMRT) in patients with head and neck carcinoma of unknown primary (HNCUP). MATERIALS AND METHODS: A single-centre prospective phase II trial design was used in two sequential studies to evaluate TM-IMRT for HNCUP. Patients were investigated for primary tumour site using examination under anaesthetic and biopsies, computed tomography ± magnetic resonance imaging (MRI) or 18-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT). Patients received IMRT to the potential primary tumour sites and elective cervical nodes. Concomitant chemotherapy was used in patients who received primary radiotherapy or those with nodal extracapsular extension. RESULTS: Thirty-six patients with HNCUP were recruited; 72% male. Twenty-five patients (69.4%) had p16-positive disease. Two year mucosal and local nodal control rates were 97.1% (95% confidence interval 91.4-100) and 89.8% (78.4-100), respectively. One mucosal primary was detected 7.3 months after TM-IMRT and three patients died from recurrent/metastatic squamous cell carcinoma of the head and neck. Twelve patients (33%) developed grade 3 (Late Effects in Normal Tissue-Subjective, Objective, Management and Analytical; LENT-SOMA) dysphagia with a 1 year enteric tube feeding rate of 2.7%. The high-grade subjective xerostomia rate (LENT-SOMA) at 24 months after IMRT was 15%. CONCLUSIONS: At a median follow-up of 36.1 months, the use of TM-IMRT was associated with good local control. Toxicity was comparable with previously reported TM-IMRT regimens encompassing similar mucosal volumes.

Do traditional risk stratification models for cerebrovascular events apply in irradiated head and neck cancer patients?

BACKGROUND: Primary radical radiotherapy (RT) for head and neck cancer (HNC) often results in significant radiation dose to the carotid arteries. AIM: We assessed whether HNC patients are at increased risk of a cerebrovascular event primarily due to RT or other risk factors for atherosclerosis by (i) risk-stratifying patients according to validated QRISK-2 and QSTROKE scores and (ii) comparing the prevalence of carotid artery stenosis (CAS) in irradiated and unirradiated carotid arteries. DESIGN: HNC patients treated with an RT dose >50 Gy to one side of the neck ≥2 years previously were included. METHODS: QRISK-2 (2014) and Q-STROKE (2014) scores were calculated. We compared the prevalence of CAS in segments of the common carotid artery on the irradiated and unirradiated sides of the neck. RESULTS: Fifty patients (median age of 58 years (interquartile range (IQR) 50-62)) were included. The median QRISK-2 score was 10% (IQR 4.4-15%) and the median QSTROKE score was 3.4% (IQR 1.4-5.3%). For both scores, no patient was classified as high risk. Thirty-eight patients (76%) had CAS in one or both arteries. There was a significant difference in the number of irradiated arteries with stenosis (N = 37) compared with unirradiated arteries (N = 16) (P < 0.0001). There were more plaques on the irradiated artery compared with the unirradiated side - 64/87 (73.6%) versus 23/87 (26.4%), respectively (P < 0.001). CONCLUSIONS: Traditional vascular risk factors do not play a role in radiation-induced carotid atherosclerosis. Clinicians should be aware that traditional risk prediction models may under-estimate stroke risk in these patients.

Current attitudes of head and neck oncologists in the United Kingdom to induction chemotherapy for locally advanced head and neck cancer: a survey of centres participating in a national randomised controlled trial.

OBJECTIVES: Induction chemotherapy (IC) followed by chemoradiation (CRT) for locally advanced squamous cell head and neck cancer (SCCHN) remains controversial in the absence of clear evidence to define its role. As part of a prospective, randomised, multicentre study of CRT for stage III/IV laryngeal/hypopharyngeal cancers (ART DECO, CRUK/10/018), we have examined the attitudes of oncologists in the United Kingdom (UK) to IC. MATERIALS AND METHODS: Head and neck oncologists across the UK who expressed an interest in participating in the ART DECO trial were asked to complete a short written questionnaire designed to identify current UK practice of IC for stage III-IVb SCCHN. Completed questionnaires were returned to the clinical trials office prior to patient recruitment. RESULTS: Clinicians from twenty-five/48 centres (52.1%) responded. Twenty centres (80%) elected to use IC in the trial. For stage III disease, 80% of centres did not prescribe IC for T1N1 disease and 60% did not offer IC for T3N0 disease. Patients with bulky primary tumours or extensive nodal disease were more likely to receive IC. Thirteen prescribing centres (65%) use 3 drugs (docetaxel, cisplatin, and 5-fluorouracil) compared to 7 (35%) using 2 drugs (cisplatin and 5-fluorouracil). Fifteen centres (75%) prescribed 2 cycles of IC, and 5 (25%) prescribed 3 cycles. There was variation in the dosage for both the 2- and 3-drug regimens. CONCLUSION: Results suggest that clinical practice in the UK is currently divided between a 2- versus 3-drug regimen for IC for specific subgroups of patients. A consensus regarding the optimal combinations and dosages is required before further optimization of systemic therapy with other cytotoxics and biological agents is attempted.

Clinical features of radiation-induced carotid atherosclerosis.

Carotid arteries frequently receive significant incidental doses of radiation during the treatment of malignant diseases, including head and neck cancer, breast cancer and lymphoma. Vascular injury after treatment may result in carotid artery stenosis and increased risk of neurological sequelae, such as stroke and transient ischaemic attack. The long latent interval from treatment to the development of clinical complications makes investigation of this process difficult, particularly in regard to the design of interventional clinical studies. Nevertheless, there is compelling clinical evidence that radiation contributes to carotid atherosclerosis. This overview examines the effect of radiotherapy on the carotid arteries, the underlying pathological processes and their clinical manifestations. The use of serum biomarkers in risk-prediction models and the potential value of new imaging techniques as tools for defining earlier surrogate end points will also be discussed.