No abstract

The British Standards Institution 'Guide to implementing an effective respiratory protective device programme' (BS 4275) lists assigned protection factors (APFs) for various types of respiratory protective equipment (RPE). The APFs were allocated either on the basis of available workplace studies data which met set criteria or on the basis of professional judgement that there is equivalence between its operation and that of a device for which an APF is derived from workplace data. However, in many cases no workplace study information exists to support this professional judgement. As an interim measure, pending information based on workplace measurements, the breathing resistance of a range of tight-fitting RPE from negative pressure filtering devices through to self-contained positive pressure breathing apparatus was measured at various breathing rates. The relative inhalation resistances were then compared on the assumption that similar breathing resistance performance is likely to give similar inward leakage on a facepiece and hence similar protection if all other factors, such as fit, etc., are equal. This work indicates that for most devices the allocation of APFs by analogy to other devices seems to be acceptable. However, there appears to be no justification for the allocation of an APF value of 100 to continuous flow compressed air line breathing apparatus. It is recommended that it should be lowered to 40 until there is valid workplace study data to support the current APF of 100. The work provides an informative insight into the relative performance of devices.

Background: During the SARS-CoV-2 virus pandemic, University Hospital Birmingham NHS Trust Oncology Department incorporated the ultrahypofractionated regime of 26Gy/5 fractions alongside the moderate hypofractionated regime of 40Gy/15 fractions as part of local adjuvant breast radiotherapy treatment (RT) for eligible patients. We conducted a local study to assess the real-life experience of patients undergoing ultrahypofractionated schedule to compare feasibility and toxicity to the fast-forward trial during the COVID − 19 pandemic. Methods: A single institution, retrospective, qualitative study. Patients included had early-stage breast cancer and received adjuvant radiotherapy between 23 March 2020 and 31 May 2020, a total of 211 patients. Inclusion was irrespective of any other neoadjuvant/adjuvant treatments. Data were collected retrospectively for treatment dose, boost dose and toxicity. Results: Of the total 211 patients, 85 were treated with 26Gy in 5# and 19 patients received a boost as per the fast-forward protocol. Of these 85 patients, 15·9% did not report any skin toxicity post-treatment. 63·5% of patients reported RTOG Grade 1, 15·9% had RTOG Grade 2, and 1·6% reported RTOG Grade 3 skin toxicity. 3·2% of the patients could not be contacted for follow-up. Of the 19 patients who received a breast boost, 10·53% reported no skin changes. 78·9% reported Grade 1 skin toxicity. Both Grades 2a and 2b skin toxicity were reported by 5·26% each. The patient demographics and tumour characteristics in our study cohort were comparable to those within the fast-forward trial. In terms of post-RT skin toxicity, fewer patients reported any toxicity in the UHB patient cohort versus those in the trial, and the number of Grade 2/3 toxicities reported was also low. A delay in toxicity reporting from 2 weeks for 40Gy/15 to 3 weeks for 26Gy/5 was observed. Conclusion: Our study concluded that offering ultrahypofractionation was convenient for patients; reducing the number of hospital visits during the SARS-CoV-2 virus pandemic appeared safe in terms of acute post-RT-related skin toxicity. The reduced hospital visits limited exposure of patients and staff to the SARS-CoV-2 virus while also ensuring efficient use of Radiotherapy Department resources. Local follow-up protocols have been amended to ensure review at 3 weeks for the 26Gy/5 schedule to acknowledge the delay in acute toxicity development. To date, there is only 5-year toxicity and relapse data available from the fast-forward trial; therefore, hypofractionation schedules should be offered to patients as long as they fulfil the criteria and understand the limitations of the study as well as accelerated peer review processes in the face of the pandemic.

Protection factors were measured on full face mask power assisted respirators when worn by experienced asbestos removal operatives under simulated asbestos removal work conditions. The sulfur hexafluoride test method as defined in European Standards was employed to determine the leakage into the respirators. Protection factors were measured on a total of 21 test volunteers. The test method allowed protection factors to be related to wearer activities and practices. Poor fitting techniques and simulated reduction in the respirator's performance resulted in a reduction in the protection factor. Visual inspection of the RPE usually worn by the volunteers identified inadequate maintenance. This study re-emphasises that careful selection, facepiece fit testing and correct use and maintenance of RPE are essential to ensure optimum protection to the wearer.