Reflection is a way of evaluating best practice and challenging existing norms, while at the same time, considering one’s personal values and assumptions in our personal and professional lives. However, many health practitioners may lack the skills to do this effectively. Through participation in a series of three workshops, practitioners in the Radiation Medicine Program at Princess Margaret Hospital have learned and acquired new skills to encourage reflection and reflective practice in themselves, their colleagues as well as with their students. A pre- and post-course survey was used to ascertain their level of knowledge of reflection and reflective practice. An additional survey at 3 months assessed the frequency of use and ongoing comfort level with reflective practice. Results of the evaluation indicate that the participants’ knowledge of reflective practice has improved their understanding of reflection in clincal practice. They recognize the importance of reflection and anticipate increasing their use of reflection in/on practice. As well, participants have been able to sustain the positive momentum 3 months after the course was delivered.

Purpose: To evaluate the toxicity of hypofractionated helical intensity-modulated radiotherapy (IMRT) for men with intermediate- and high-risk prostate cancer.

Methods and Materials: A retrospective toxicity analysis was performed in 22 patients treated definitively with hypofractionated helical IMRT. The helical IMRT were designed to deliver 75 Gy in 2.5 Gy/fraction to the prostate gland, 63 Gy in 2.1 Gy/fraction to seminal vesicle, and 54 Gy in 1.8 Gy/fraction to pelvic lymph nodes. No patient received hormonal therapy. Toxicity was graded by the Radiation Therapy Oncology Group (RTOG) scales.

Results: All patients tolerated the treatment well without treatment interruption, and there was no Grade 3 or more acute toxicity. With a median follow-up of 24.5 months, there was no Grade 3 or more late toxicity. The late Grade 2 gastrointestinal (GI) and genitourinary (GU) toxicity for total 22 patients were 9.1% and 18.2%, respectively, and the late Grade 1 GI and GU toxicity were 18.2% and 50%, respectively. Late GU toxicity was associated with greater bladder volume irradiated ≥70 Gy. Late GI toxicity did not correlate with any of the dosimetric parameters.

Conclusions: This study demonstrate that hypofractionated helical IMRT with high biologic effective dose (BED) is well tolerated with favourable toxicity rate. If longer follow-up periods and larger cohorts confirm the favourable biochemical control rate and our favourable toxicity assessment results, the hypofractionated IMRT (total 75 Gy, 2.5 Gy/fraction) might be implemented in clinical field for treatment of prostate cancer.

Purpose: To evaluate the accuracy of an external immobilisation system in patients receiving radiotherapy for prostate cancer.

Methods: Portal Imaging data were audited in 20 patients treated using an in-house immobilisation system and 20 patients treated using an indexed commercial immobilisation system (Combifix™). Individual and group random and systematic errors were calculated to determine the accuracy of set-up using skin marks alone and with a no-action-level protocol.

Results: The initial results showed a larger systematic error in the Combifix™ in the anterior-posterior direction (2.7 mm) compared with the in-house system (1.5 mm). The possible source of this was identified as the difficulty in accurately aligning the laser to a curved couch top prior to setting the isocentre height. A change in the process of setting the isocentre was introduced, and comparable baseline set-up accuracy was achieved. This was with a systematic error of ≤2.0 mm and a random error ≤1.5 mm of patient position set-up error with skin marks alone, and using the Combifix™. The systematic errors were further reduced to <1 mm with an off-line no-action-level protocol.

Conclusion: Using the Combifix™ system a high level of set-up accuracy was reproduced in routine daily practice.

Ensuring reproducibility in any radiotherapy technique is vital to ensure that a geometric miss does not occur. Patient position and comfort play a major part in the reproducibility of setups.

Purpose: To study the effect on accuracy of the introduction of a bellyboard to the existing prone technique used for radical radiotherapy treatment of prostate cancer.

Materials and Methods: Thirty patients were treated using the bellyboard in the standard method. Portal images were compared with those of a control group of patients who had treatment with no rigid immobilisation. Patients in both groups were males with prostate cancer, who underwent radical radiotherapy treatment. Images were analysed using anatomy matching, and deviations from the isocentre were noted.

Results: Statistical analysis of the results showed no statistical significance between the groups, though within the control group there were more deviations over 0.5 cm from the isocentre position than in the bellyboard group.

Conclusions: Introduction of the bellyboard was seen to be equivalent to the use of the control technique. When the deviations from isocentre position were evaluated for each group, the control group had more deviations over 0.5 cm than the bellyboard group.

Aims: Endometrial cancer is the commonest malignancy of the female genital tract. Surgery forms the cornerstone of treatment with adjuvant therapy proven to reduce local recurrence without demonstrating a clear survival benefit. The selection of adjuvant therapy is becoming increasingly more complex. The aim of this study was to investigate current adjuvant practices by reviewing outcomes of patients with endometrial cancer treated with intracavitary vaginal brachytherapy (VB).

Materials & Methods: A retrospective analysis was carried out of all women with Stage II endometrial endometroid adenocarcinoma treated at Weston Park Hospital, Sheffield with adjuvant VB from 2003–2006. The data collected and analysed included histology, stage and grade of disease, radiotherapy treatment–related parameters, morbidity, recurrence rates and survival rates. Kaplan-Meier was used to analyse recurrence-free and overall survival rates. Wilson’s score was used to determine statistical significance of outcomes. Attention was focused on the method of treatment delivery, and this was compared with available literature.

Results: In total, 33 patients were identified. All patients were treated with LDR 48 Gy prescribed to the surface of the applicator. Median follow-up was 36 months. Vaginal, pelvic and distant relapse rates were 9%, 15% and 18%, respectively. Recurrence-free and overall survival rates were 78.8% and 84.8%, respectively. Six of the seven patients (86%) who recurred developed distant metastases, not influenced by VB. No severe (Grade 3 or 4 toxicity) was recorded. When vaginal relapse rates were compared to published trials based on technique used, no statistically significant difference was demonstrated.

Conclusion: Rates of vaginal relapses were comparable to the available literature suggesting current VB practice is an effective adjuvant local treatment. The study highlights the importance of surveillance and patient education regarding toxicity and its prevention with particular attention drawn to vaginal stenosis.

The partial volume (spatial) response of four ionization chambers (Keithley) in kilovoltage X-ray beams, generated by the Philips Super 80CP X-ray unit, was assessed. The volume of the ionization chambers were of 10 cm3, 15 cm3, 150 cm3, and 600 cm3 used with Keithley electrometer Model 35040. The beam output was measured using a monitor chamber (Radcal 6.0 cm3) placed close to the collimator. The source to chamber distance was kept constant at 1 m. For the measurement of the response of ionization chambers of 15 cm3, 150 cm3, and 600 cm3, a slit of 2.0 mm width was made in a lead sheet of 3.2 mm thick and size of 30 × 30 cm2 and was placed on the ionization chamber. The measurements were made for 81 kVp, 400 mA, and 0.25 s and the slit was moved at an increment of 2.0 mm over the entire length of the chamber. For the measurements of the ionization chamber of 10 cm3 (CT chamber), the beams of 120 kVp, 200 mA and 0.2 s were generated, and a slit of 5 mm width was made in a similar lead sheet that was moved at an increment of 5.0 mm. From the result it appears that the sensitive volumes of the ionization chambers affect the response of the ionization chamber to incident radiation.

Background: Endometrial cancer vaginal recurrence in a patient deemed unsuitable for EBRT. Brachytherapy proposed although standard image-guidance insufficient.

Proposed Solution: PET-CT image-guidance.

Results: PET-CT acquired with brachytherapy applicator in situ. BTV delineated by the Nuclear Medicine physician. All subsequent volumes delineated by the Clinical Oncologist. 2 phase plan delivered with minimal toxicity.

The quality factor for x-rays, gamma rays and electrons assigned as one need to be revised. It is observed that as the energy decreases, mean lethal radiation dose (Do)decreases as well and become more potent. It is therefore proposed that radiation quality in biological systems should be assessed in the mitotic phase of the cell cycles. Furthermore, based on the mean lethal radiation dose within specific energy range, an appropriate quality factor of x-rays, gamma rays and electrons should be assigned.