Background: Virtual environments in medical education are becoming increasingly popular as a learning tool. However, there is a large amount of evidence linking these systems to adverse effects that mimic motion sickness. It is also proposed that the efficacy of such systems is affected by how well they engage the user, which is often referred to as presence.

Purpose: This primary purpose of this study was to look at the side effects experienced and presence in the Virtual Environment for Radiotherapy Training (VERT) system which has recently been introduced.

Method: A pre-VERT questionnaire was given to 84 subjects to ascertain general health of the subjects. The simulator sickness questionnaire was utilised to determine the side effects experienced, whereas the igroup presence questionnaire was used to measure presence. Both questionnaires were given immediately after use of the VERT system.

Results: The majority of symptoms were minor; the two most commonly reported symptoms relating to ocular issues. No relationship was seen between simulator sickness and presence although subjects with a higher susceptibility to travel sickness had reported higher levels of disorientation and nausea. There was also a decrease in involvement with the system in subjects with a higher susceptibility to travel sickness.

Accurate patient positioning is vitally important in intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer. The introduction of kilovoltage (kV) on-board imaging (OBI) at our centre was anticipated to improve the accuracy and efficiency of H&N IMRT patient position verification over traditional megavoltage (MV) electronic portal imaging (EPI). This study compares these imaging systems with a phantom accuracy study and retrospective analysis of imaging workload in H&N IMRT at our centre. Six therapists performed online evaluation of phantom images, and residual positional errors for each system were recorded. The largest residual error was 1 mm for OBI and 3 mm for EPI. The estimated improvement in residual error in OBI over EPI was 0.57 mm (95% confidence interval 0.33–0.81 mm), suggesting treatment staff would be better able to detect set-up deviations with OBI. Electronic treatment records of 20 H&N IMRT patients (10 verified daily with MV EPI and 10 with kV OBI) were analysed. Mean imaging session duration was 9.51 min for EPI and 9.76 min for OBI. Analysis found no evidence of an effect on duration due to the imaging system used for this subset of patients (p = 0.664).

Adaptive radiation therapy is a promising concept that allows individualised, dynamic treatment planning based on feedback of measurements. The TomoTherapy Planned Adaptive application, integrated to the helical TomoTherapy planning system, enables calculation of actual dose delivered to the patient for each treatment fraction according to the pretreatment megavoltage computed tomography (MVCT) scan and image registration. As a result, new fractionation treatment plans are available if correction is necessary. In order to evaluate the real clinical effect, biological dose is preferred to physical dose. A biological parameter, biologically effective uniform dose (), has the advantages of not only reporting delivered dose but also facilitating the analysis of dose–response relations, which link radiation dose to the clinical effect. Therefore, in this study, four lung patients’ adaptive plans were evaluated using the in addition to physical doses estimated from the TomoTherapy Planned Adaptive module. Higher complication-free tumour control probability (P+) (of about 8%) was observed in patients treated with larger dose-per-fraction by using the in addition to the physical dose. Moreover, a significant increase of 13.2% in the P+ for the adaptive TomoTherapy plan in one of the lung cancer patients was also observed, which indicates the clinical benefit of adaptive TomoTherapy.

Purpose: A questionnaire was developed to explore variations among radiation oncologists in managing early-stage breast cancer, specifically radiation-induced skin reaction (RISK).

Materials and methods: A survey was designed to target a database of 962 radiation oncologists, self-identified as ‘interested in treatment of breast cancer’. This database was obtained from the American Society of Therapeutic Radiology & Oncology (ASTRO). Participants submitted the survey online or by mail. Overall response to the survey was 282 out of 962 (29.3%). Data were handled as rates.

Results: Out of 282 respondents, 275 (97.5%) agreed on delivering 4500–5040 cGy. The most frequently employed dose was 5040/180 cGy. Three-dimensional-conformal (3DCRT) treatment was used by 55.4%, intensity-modulated radiotherapy (IMRT) by 24.5%, and conventional by 20.1%. Almost all (92.5%) agreed on using boost in ductal carcinoma in situ (DCIS). Image-guided boost placement (IGBP) was used by 87.3%. Boost dose included variations: 50.2, 7.3, and 18% used 1000, 1200, and 1400 cGy, respectively; the remaining used higher doses. In management of RISK, Aquaphor was the most popular agent (72.1%). Other agents were utilized either alone or in combination. Almost all (99%) agreed that large breast size increases RISK.

Conclusion: This survey offers a glimpse of management practices in early-stage breast cancer amongst a cross-section of radiation oncologists in the United States. Although there appears to be an overall congruence on the doses and techniques of radiation delivery, the management of RISK is varied. Additional efforts are warranted to standardize practices in order to practice evidence based medicine in a cost-effective manner.

Background and purpose: Radiotherapy is used for the treatment of malignant tumours, and may be used as the primary therapy. It is also common to combine radiotherapy with surgery, chemotherapy, hormone therapy or some combination of them. Even if the tumour is treated intensively, women diagnosed with breast cancer may develop a recurrence. Most recurrences may be in the form of distant metastases, development of multi-drug resistance phenotype or both together. This study demonstrated that some of the multi-drug resistant cancer cells may also become radioresistant.

Materials and Methods: Chemoresistance in paclitaxel (MCF-7/Pac), docetaxel (MCF-7/Doc), vincristine (MCF-7/Vinc), doxorubicin (MCF-7/Dox) and zoledronic acid (MCF-7/Zol) resistant MCF-7 cells were demonstrated by XTT assay. MDR1 gene expression was detected by real-time PCR in human MCF-7 breast cancer cells. Drug resistant and sensitive cells were exposed to γ-radiation and development of radioresistance was investigated.

Results: Results have indicated that paclitaxel, docetaxel, vincristine, doxorubicin and zoledronic acid–selected cells gained varying degrees of resistance to their selective drugs when compared with original MCF-7/S. MCF-7/Pac, MCF-7/Doc, MCF-7/Vinc and MCF-7/Dox cells have all acquired MDR1 expression. Among the resistant sub-lines, MCF-7/Pac and MCF-7/Doc cells were significantly cross-resistant to irradiation compared to the sensitive cells.

Conclusion: MCF-7/Pac and MCF-7/Doc cell lines were found radioresistant to γ-radiation. On the contrary, doxorubicin, vincristine and zoledronic acid resistant cancer cells were still sensitive to radiation.

Purpose: The aim of this study was to find out equivalency between two high-dose-rate (HDR) fractionation schemes, relevance to the International Commission on Radiation Units and Measurements report-38 (ICRU-38) reference volume with respect to point A dose and other ICRU reference points in two-dimensional (2D) planning.

Methods and Materials: Forty-nine patients having carcinoma of cervix of stages II–IIIB treated with external beam radiotherapy plus HDR brachytherapy (BT) were analysed. The external beam radiotherapy dose of 45 Gy/25 fractions delivered in 5 weeks followed by HDR BT delivered either in two fractions with 9.5 Gy per fraction (Group-1) or in three fractions with 7.5 Gy per fraction (Group-2) to point A. ICRU-38 recommendations were followed to determine reference volume with respect to Manchester dose point A, and biologically effective dose (BED) at different points.

Results: BED10 at bladder and rectum reference points were 17.11 ± 12.36 Gy and 13.92 ± 5.71 Gy in Group-1, and 15.69 ± 11.43 Gy and 16.24 ± 5.45 Gy in Group-2, respectively; and BED3 were 33.03 ± 29.67 Gy and 25.01 ± 12.35Gy in Group-1, and 27.00 ± 26.85 Gy and 27.44 ± 11.00 Gy in Group-2, respectively. The HDR BT reference volumes were 233.47 ± 27.30 cm3 and 227.83 ± 32.35 cm3 and corresponding CBED10 at point A with proliferation correction were 76.59 ± 2.31 Gy, and 76.41 ± 2.15 Gy for Group-1 and Group-2, respectively. The CBED10 and CBED3 at point B were 46.38 ± 2.26 Gy and 82.23 ± 0.72 Gy, respectively, for Group-1; and 45.03 ± 2.11 Gy and 82.89 ± 0.44 Gy, respectively, for Group-2.

Conclusion: No significant differences were found in the results of two HDR fractionation schemes. ICRU reference volume with respect to point A dose correlates with tumour control and is a good pre-treatment predictor in 2D planning. Neither ICRU bladder and rectum reference points nor trapezoid points showed correlation with complications. The trapezoid points did not also show any correlation with loco-regional control.

We present the case of 68-year-old white man who presented with lung cancer in Addisonian crisis due to a pituitary metastasis. He was successfully treated with radiotherapy which reversed his visual field deficits. Pituitary metastasis as the first manifestation of malignancy is rare but, should be considered in the differential diagnosis of patients presenting with endocrine disturbances and visual problems.

Lead cut-outs used to shape fields in kilovoltage radiotherapy can increase the surface dose on the patient. The physical processes leading to increased surface doses are summarised, and an empirical investigation of the efficacy of various coatings in reducing the skin dose generated by secondary electrons released in the lead during irradiation is presented, based on measurements using a thin window parallel plate ionisation chamber in 135 kVp and 225 kVp beams from a Pantak DXT-300 kilovoltage therapy unit. A new flexible coating for lead cut-outs has been formulated and tested. This coating, which is a combination of Copydex and emulsion paint, has been shown to be effective in reducing the skin dose generated by secondary electrons released in the lead during irradiation. The coating is easy to clean, and its inherent elasticity prevents cracking of the coating in clinical use. Its only disadvantage is that rough handling, or contact with sharp objects, can peel the coating at the point of contact.