Radiotherapy with or without mitomycin c in the treatment of locally advanced head and neck cancer: results of the IAEA multicentre randomised trial.

BACKGROUND AND PURPOSE: Single agent mitomycin c (MMC) has been shown to improve the outcome of radiotherapy in single institution trials. In order to confirm these findings in a broader worldwide setting, the International Atomic Energy Agency (IAEA) initiated a multicentre trial randomising between radiotherapy alone versus radiotherapy plus MMC. MATERIAL AND METHODS: Patients with advanced head and neck cancer were treated with primary curative radiotherapy (66 Gy in 33 fractions with five fractions per week) +/-a single injection (15 mg/m(2)) of MMC at the end of the first week of radiotherapy. Stratification parameters were tumour localization, T-stage, N-stage, and institution. A total of 558 patients were recruited in the trial from February 1996 to December 1999. Insufficient accrual and reporting led to the exclusion of three centres. The final study population consisted of 478 patients from seven centres. Patients had stage III (n=223) or stage IV (n=255) squamous cell carcinoma of the oral cavity (n=230), oropharynx (n=140), hypopharynx (n=65) or larynx (n=43). Prognostic factors like age, gender, site, size, differentiation and stage were well balanced between the two arms. RESULTS: The haematological side effects of MMC were very modest (<5% grade 3-4) and did not require any specific interventions. Furthermore, MMC did not enhance the incidence or severity of acute and late radiation side effects. Confluent mucositis and dry skin desquamation was common, occurring in 56% and 62% of patients, respectively. The overall 3-year primary locoregional tumour control, disease-specific and overall survival rates were 19, 36 and 30%, respectively. Gender, haemoglobin drop, tumour site, tumour and nodal stage were significant parameters for loco-regional tumour control. There was no significant effect of MMC on locoregional control or survival, except for the 161 N0 patients, where MMC resulted in a better loco-regional control (3-year estimate 16% vs. 29%, P=0.01). CONCLUSIONS: The study did not show any major influence of MMC on loco-regional tumour control, survival or morbidity after primary radiotherapy in stage III-IV head and neck cancer except in N0 patients where loco-regional control was significantly improved.     

Design optimization and efficiency enhancement of axial junction nanowire solar cells utilizing a forward scattering mechanism

We report the design, optimization, and performance analysis of three axial junction nanowire solar cells (NW SCs) based on cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and copper zinc tin sulfide (CZTS) with significant improvement in their optical and electrical characteristics compared to their planar counterparts. It is shown that the performance of these NW SCs can be further improved by incorporating a hemispherical indium doped tin oxide (ITO) forward scatterer on top of the ITO front contact of the solar cells. We also compare forward scatterer incorporated NW SCs with forward scatterer incorporated planar solar cells (PSCs) and observe that forward scatterers significantly enhance the absorption in both cases. We further study the optimum size and arrangement of ITO hemispheres that result in improved photocurrent. In optimum cases, the incorporation of forward scatterers leads to absorption enhancement of 7.8%, 5.36%, and 8.8% in PSCs, and 21.4%, 7.36%, and 6.02% in NW SCs, respectively, for CdTe, CIGS, and CZTS absorbers in the same order. From the absorption profile at various wavelengths, it is found that forward scatterers enhance absorption in the 450–600 nm wavelength range, while nanowires improve absorption in the 600–800 nm range, and their combination results in an improved absorption profile for the entire visible wavelength range. We also observe increased electron–hole-pair (EHP) generation rate due to increased field-scattering and light concentration at the center of the nanowire below forward scattering hemispheres, leading to 46%, 32%, and 82.5% improvement in power conversion efficiency (PCE) for the three absorber layers, respectively. The effects of Al₂O₃ and SiO₂ passivation layers surrounding the nanowires of the optimized cells are observed, and we conclude that the CIGS absorber benefits the most when the SiO₂ passivation layer is used, increasing its PCE from 29.72% to 32.43%, while the PCEs of CdTe and CZTS are unaffected by the passivation layer due to competing effects of reduced absorption and reduced surface recombination.

We report the design and performance analysis of forward scatterer incorporated axial junction nanowire solar cells based on CdTe, CIGS, and CZTS with significant improvement in their optoelectronic properties compared to their planar counterparts.     

Subclavian stenting in a hostile aortic arch facilitated by a low-profile brachial artery through-and-through access

Subclavian stenting can be extremely difficult in a hostile type II aortic arch (with acute angulation of the subclavian artery origin) or type III aortic arch. This case illustrates use of a low-profile system to gain through-and-through (flossing) access through the brachial artery to facilitate stenting via the femoral approach. This approach can be useful in patients with small brachial arteries where the risk of complication may be high if a standard vascular sheath was placed for stenting via the brachial approach. This technique also avoids the use of a surgical cut down.     

Impact of UK National Guidelines based on FRAX®– comparison with current clinical practice

Objective To assess whether clinician‐determined treatment intervention thresholds are in line with the assessment of fracture risk provided by FRAX^® and treatment recommendations provided by UK guidelines produced by the National Osteoporosis Guidelines Group (NOGG). Design, Patients and Measurements This was a retrospective cohort analysis of 288 patients consecutively referred for dual‐energy X‐ray absorptiometry (DXA) scanning from primary care immediately prior to the introduction of the FRAX^® algorithm. In addition to DXA assessment, patients completed a clinical risk factor questionnaire which included risk factors used in the FRAX^® algorithm. Initial risk assessment and treatment decisions were performed after DXA. FRAX^® was used, retrospectively, with femoral neck T‐score, to estimate fracture risk which was applied to NOGG to generate guidance on treatment intervention. Clinician‐ and NOGG‐determined outcomes were audited for concordance. Results There was concordance between clinician and NOGG treatment decisions in 215 (74·6%) subjects. Discordance was observed in 73 (25·3%) subjects. In the discordant group, seven subjects were given lifestyle advice when NOGG recommended treatment, 42 given treatment when NOGG recommended lifestyle advice only, and 24 were referred to a metabolic bone clinic for further evaluation. The reasons for treatment differences in subjects recommended treatment by clinician but not NOGG were largely (90·2%) attributed to the use of lumbar spine bone mineral density (BMD). Conclusions There is high concordance between clinician‐determined and FRAX^®‐NOGG intervention. The absence of spine BMD from FRAX^® is the primary source of discrepancy. This study provides some assurance of the validity of the treatment thresholds generated from FRAX^®‐NOGG in ‘real‐world’ usage.