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Dose Fractionation Schedules (dose + fractionation_schedule)
Selected AbstractsBasal cell carcinoma of the nose: An Australian and New Zealand Radiation Oncology patterns-of-practice studyJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2008MJ Veness Summary Patients with a basal cell carcinoma (BCC) of the nose may be recommended radiotherapy (RT) with a wide variation in techniques and prescribed dose fractionation schedules between clinicians. The aim of this study was to ascertain variability in the patterns of practice among Australian and New Zealand radiation oncologists (ROs) when treating BCC arising on the nose. A postal survey was sent to 222 practising ANZ ROs detailing 12 different clinical scenarios of a BCC arising on the nose. The treatment selected for each scenario was analysed according to clinician's attitudes, training, experience and the availability of resources. The response rate was 74% (165/222) with 90 respondents treating non-melanoma skin cancer. Training was perceived to have a marked influence on treatment practice by most (79%). In total, 72% of ROs were ,very certain' in their choice of a dose fractionation schedule for obtaining local control and 61% for a satisfactory cosmetic outcome, respectively. Most (76%) favoured low-voltage photons over electrons as the optimal method of treatment, although for certain clinical scenarios most would use electrons. Dose fractionation schedules were highly variable with a lower total dose and hypofractionation favoured for older patients. Low-voltage photons were favoured for the T1 BCC and electrons for the T2 and T4 BCC. Nearly one-third of the ROs chose megavoltage photons for the T4 lesion. There is marked variation in treatment practices in terms of recommending RT over other treatment options, the choice of RT method, the dose fractionation schedule, the extent of field margins and the point of dose prescription. [source] How do waiting times affect radiation dose fractionation schedules?JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2000Conrade Iv Franklin SUMMARY The purpose of the present paper was to evaluate the changing patterns of dose prescription at the Queensland Radium Institute from 1995 to 1998 inclusive. Data were analysed from the treatment files collected on each patient and these were compared with data on delay time. There has been an increased use of shorter fractionation schedules in the period studied. Paradoxically, radical treatments have become longer. The average number of fractions for all patients was 17.4 and for palliative treatments it was 7.4. The monthly delay varied from 0 to 22 working days and the average was 7 working days. When fraction number was compared to treatment delay, there was a negative linear correlation (R = ,0.25). The correlation was stronger (R = ,0.467) when palliative treatments were compared, indicating that clinicians were more prepared to alter palliative treatments in the presence of a treatment delay than curative ones. [source] Role of definitive radiotherapy in treating patients with inoperable Merkel cell carcinoma: The Westmead Hospital experience and a review of the literatureAUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 4 2009Clare SL Koh ABSTRACT Merkel cell carcinoma (MCC) is an uncommon aggressive primary cutaneous neuroendocrine carcinoma with a propensity to spread to regional lymph nodes and distant sites. The head and neck is the commonest site for presentation (50,60%) and recent evidence suggests patients treated with excision (to achieve a negative microscopic margin) and adjuvant wide-field radiotherapy (RTx) have an improved survival compared with surgery alone. Surgery is often not possible in elderly patients with multiple co-morbidities and in patients with advanced lesions. Definitive RTx therefore remains an option in these inoperable patients, with data to report its benefit. We report the results of eight patients with inoperable MCC treated with RTx alone between 1993 and 2007 at Westmead Hospital, Sydney, Australia, and also review the relevant literature on definitive RTx in the treatment of MCC. The median age at diagnosis was 82.5 years in five women and three men. All patients were Caucasian and none were immunosuppressed. Seven of eight patients were clinically node-positive. The mean duration of follow up was 12 months. A median dose of 50 Gy was prescribed. Seven of eight patients with inoperable MCC achieved in-field control, with most eventually relapsing distantly. Treatment-related toxicity was acceptable. In keeping with our results, other studies also report high rates of in-field locoregional control following RTx alone. These findings highlight the radioresponsiveness of advanced MCC and support a recommendation of moderate-dose RTx alone in select cases. Lower-dose palliative dose fractionation schedules (e.g. 25 Gy in five fractions) may be considered in patients of very poor performance status. [source] | ||||||||||