Ruheena Mendes

Noise estimation from averaged diffusion weighted images: Can unbiased quantitative decay parameters assist cancer evaluation?

Multiexponential decay parameters are estimated from diffusion‐weighted‐imaging that generally have inherently low signal‐to‐noise ratio and non‐normal noise distributions, especially at high b‐values. Conventional nonlinear regression algorithms assume normally distributed noise, introducing bias into the calculated decay parameters and potentially affecting their ability to classify tumors. This study aims to accurately estimate noise of averaged diffusion‐weighted‐imaging, to correct the noise induced bias, and to assess the effect upon cancer classification.

Synthetic Lethality and PARP-Inhibitors in Oral and Head & Neck Cancer

Head and neck cancer refers to a group of malignancies that affects the epithelium of the upper aereodigestive tract, primarily the lip and mouth, pharynx and larynx. Head and neck cancer is strongly associated with tobacco smoking, alcohol consumption and betel nut chewing, and indeed a reduction in the exposure to these risk factors has determined a recent decrease in incidence rates in many countries. There remains, however, a significant increase in head and neck cancer rates in those regions where tobacco epidemic continues, as well as in the number of oral cancers related to HPV infection (in particular cancer of the oropharynx, tonsil, and base of the tongue), which typically affect young adults with no history of exposure to tobacco or alcohol. Treatment of head and neck cancer has significantly changed during the last few decades, and an increasing number of individuals are currently offered combined chemoradiotherapy as single treatment modality for organ preservation or in association with surgery to improve prognosis. Unfortunately, the majority of head and neck cancer patients eventually succumb to their disease, with inoperable locoregional recurrences and lack of response to chemoradiotherapy representing the main causes of death. There is an urgent need of novel molecular-targeted therapeutics that could overcome the limitations of current treatment modalities. This paper reviews the characteristics of a novel group of promising antineoplastic agents, poly (ADP-ribose) polymerases (PARP) inhibitors, which cleverly target one of the mechanisms cancer cells use to escape the toxic effect of chemoradiation, and describe the potential benefits of their addition to current limited range of head and neck cancer antineoplastic agents.

Results of a multicentre randomised controlled trial of cochlear-sparing intensity-modulated radiotherapy versus conventional radiotherapy in patients with parotid cancer (COSTAR; CRUK/08/004)

Purpose About 40–60% of patients treated with post-operative radiotherapy for parotid cancer experience ipsilateral sensorineural hearing loss. Intensity-modulated radiotherapy (IMRT) can reduce radiation dose to the cochlea. COSTAR, a phase III trial, investigated the role of cochlear-sparing IMRT (CS-IMRT) in reducing hearing loss. Methods Patients (pT1-4 N0-3 M0) were randomly assigned (1:1) to 3-dimensional conformal radiotherapy (3DCRT) or CS-IMRT by minimisation, balancing for centre and radiation dose of 60Gy or 65Gy in 30 daily fractions. The primary end-point was proportion of patients with sensorineural hearing loss in the ipsilateral cochlea of ≥10 dB bone conduction at 4000 Hz 12 months after radiotherapy compared using Fishers exact test. Secondary end-points included hearing loss at 6 and 24 months, balance assessment, acute and late toxicity, patient-reported quality of life, time to recurrence and survival. Results From Aug 2008 to Feb 2013, 110 patients (54 3DCRT; 56 CS-IMRT) were enrolled from 22 UK centres. Median doses to the ipsilateral cochlea were 3DCRT: 56.2Gy and CS-IMRT: 35.7Gy (p < 0.0001). 67/110 (61%) patients were evaluable for the primary end-point; main reasons for non-evaluability were non-attendance at follow-up or incomplete audiology assessment. At 12 months, 14/36 (39%) 3DCRT and 11/31 (36%) CS-IMRT patients had ≥10 dB loss (p = 0.81). No statistically significant differences were observed in hearing loss at 6 or 24 months or in other secondary end-points including patient-reported hearing outcomes. Conclusion CS-IMRT reduced the radiation dose below the accepted tolerance of the cochlea, but this did not lead to a reduction in the proportion of patients with clinically relevant hearing loss.