Feedback survey on the Royal Australian and New Zealand College of Radiologists Faculty of Radiation Oncology trainee research requirement.

INTRODUCTION: The Royal Australian and New Zealand College of Radiologists Faculty of Radiation Oncology (FRO) requires trainees to complete a research project prior to the exit (phase II) examinations. We report results of a survey of current FRO trainees and Fellows graduating since 2013, regarding their experience of the overall requirement, supervision, barriers to project completion and subsequent publication. METHODS: A 32-question online survey was sent via email to 285 FRO members in July 2019. Responses were anonymous. RESULTS: The overall response rate was 32% (trainees 41%, Fellows 21%); 70% of respondents were trainees. About three-quarters of projects were retrospective reviews (64%) or surveys (13%), 94% met College requirements at first submission, 71% were published, and 81% were presented at a scientific meeting. Most assistance was provided by the project supervisor (57%), statistician (47%), another consultant (36%) or the Director of Training (28%). Finding time amongst other clinical/curriculum commitments, rotating to another training site and availability of a suitable supervisor were notable obstacles. Over half (52%) of respondents were satisfied/very satisfied with the process overall and 20% dissatisfied/very dissatisfied; 19% and 30%, respectively, thought requiring acceptance for peer review and completion prior to the phase II examination unreasonable/very unreasonable. Four per cent reported being less likely to be involved in future research as a result of this experience. CONCLUSION: While the majority of respondents perceive the FRO research requirements as reasonable, a significant minority are not satisfied with aspects of the programme. Amendment of the pre-phase II stipulation may be worthy of consideration.

Trainee research requirements of Australasian medical colleges: How does the Faculty of Radiation Oncology compare?

INTRODUCTION: The Faculty of Radiation Oncology (FRO) of the Royal Australian and New Zealand College of Radiologists (RANZCR) currently allows several pathways for trainees to satisfy its mandatory original research requirement. In practice, the majority need to have a manuscript 'accepted to peer review' by one of five specified radiation oncology (RO) journals before being eligible to sit for the final examination. The purpose of this work was to determine the corresponding trainee research requirements of the other Australasian medical colleges and compare them with FRO as a companion to a planned FRO trainee survey on the same topic. METHODS: The Australian Health Practitioner Regulation Agency (AHPRA) website lists 16 colleges conferring medical fellowships, four of which have various sub-faculties, and the New Zealand Medical Council website lists three other separate colleges (69 entities in all). Their individual websites were interrogated to determine and tabulate their respective trainee research requirements. RESULTS: 7/69 entities (10%) do not include a research component in their published training programme. Four (5.8%) mandate actual publication of a manuscript (and additionally, FRO does also require this for journals other than the five specified). The other training programmes have less rigorous submission requirements, for example internal assessment of a research report. In addition, many allow attainment of a research higher degree (including FRO) or multiple other options as an alternative pathway. Eleven entities (including FRO) stipulate that their requirement needs to be satisfied before sitting for the exit examination. CONCLUSIONS: The current FRO trainee research requirement is at the more stringent end of the Australasian spectrum. This has advantages and disadvantages for RO trainees and their departments. The data presented here and the trainee survey will inform the RANZCR Training and Assessment Review project, ongoing at the time of writing.

Radiotherapy for parotid IgG4-related disease.

We describe the use of radiotherapy for parotid IgG4-related disease (IgG4-RD), initially misdiagnosed as Kimura's disease, with sustained good partial response in a 37-year-old male. To the best of our knowledge, this is the first reported case of radiation for extra-orbital IgG4-RD, albeit inadvertently.

Randomized double-blind trial of amifostine versus placebo for radiation-induced xerostomia in patients with head and neck cancer.

INTRODUCTION: The role of the radioprotector amifostine in ameliorating radiotherapy side effects in head and neck squamous cell carcinoma (HNSCC) is controversial. This trial aimed to determine whether pretreatment with amifostine reduced the incidence of Radiation Therapy Oncology Group grade ≥2 acute and late xerostomia in patients receiving definitive or adjuvant radiotherapy for HNSCC, without reducing tumour control or survival. METHODS: Between 14 September 2001 and 8 November 2004, 44 Royal Adelaide Hospital patients were randomized double-blind to receive amifostine (200 mg/m2 IV) or placebo (normal saline IV) 5 days/week, prior to standard radiotherapy (60-70 Gy), each having ≥75% of the parotids treated to ≥40 Gy. Side effects were assessed weekly during treatment, at 3 and 5 months after radiotherapy, then every 6 months until disease progression or death. RESULTS: The accrual target was 200 patients over 4-5 years, but the trial closed prematurely when only 44 patients had been randomized after 3 years. Of 41 evaluable patients, 80% (16/20) in the amifostine arm had grade ≥2 acute radiation salivary toxicity versus 76% (16/21) in the placebo arm (P = 1.00). The rate of grade ≥2 late radiation salivary toxicity at 12 months was 66% in the amifostine arm and 82% in the placebo arm (estimated hazard ratio 1.61, 95% confidence interval 0.74-3.49, P = 0.22). Other toxicities tended to be worse in the amifostine arm: acute grade 3-4 skin 35% vs 5% and mucous membrane 40% vs 5%; grade ≥2 vomiting 35% vs 5%, hypocalcaemia 25% vs 5% and fatigue 85% vs 33%, with only the latter retaining statistical significance after adjusting for multiple comparisons. There were no significant differences in failure-free (P = 0.70) or overall survival (P = 0.86), with estimated 4-year rates of 48% vs 54% and 49% vs 59% for the amifostine vs placebo arms respectively. CONCLUSION: There was no clear evidence that pretreatment with amifostine made any difference to the incidence of grade ≥2 acute or late xerostomia. Other toxicity tended to be more severe with amifostine. There was no effect on failure-free or overall survival. Acknowledging the low statistical power, these results do not support the use of IV amifostine pre-radiotherapy in HNSCC.

Quality indicators for early stage Hodgkin's lymphoma.

INTRODUCTION: The purpose of this project was to devise simple, practicable quality indicators (QIs) for the treatment of early stage (I-II) Hodgkin's lymphoma (ESHL), and to test their applicability retrospectively at a single large teaching hospital. METHODS: Of the available treatment guidelines, we chose the two eviQ (evidence and Quality, Cancer Institute New South Wales) documents first published in early 2012 (updated in 2015) for ESHL favourable and ESHL unfavourable (based upon German Hodgkin Study Group practice) as being most relevant to the Australian setting, and selected nine QIs from them viz. baseline staging investigations, discussion in a multi-disciplinary meeting, chemotherapy type and number of cycles, radiotherapy (RT) planning technique, use of dose volume histograms, dose, treatment volume and timing. We identified all patients with ESHL treated radically with chemotherapy and/or RT at the Royal Adelaide Hospital between July 2009 and July 2014, and extracted relevant data from hospital records. QI score for each item was defined as the percentage of patients who received care as recommended in the eviQ guidelines, and improvement potential as an indicator score <90%. RESULTS: Raw QI scores varied between 74-100%. When corrected for clinical circumstances legitimising deviation from the guidelines, the range was 83-100%. Only number of chemotherapy cycles (87% corrected) and RT dose (83% corrected) had improvement potential. However, compliance after publication of the eviQ guidelines was virtually perfect for each item. CONCLUSIONS: The chosen QIs for ESHL proved to be practicable to apply in this single centre review where overall compliance was high, and excellent in the latter half of the study period. We would encourage reporting of raw and corrected QI scores.

Radiation Oncology research grants awarded by the Royal Australian and New Zealand College of Radiologists: Value for money?

INTRODUCTION: The Royal Australian and New Zealand College of Radiologists (RANZCR) and other medical colleges have provided research grants from their budgets for many years. This survey-based project aimed to determine whether the RANZCR Faculty of Radiation Oncology (FRO) is realizing value for money from its seed funding, and to compare this with grant activities of the other colleges. METHODS: Eligible FRO grant recipients between 1999 and 2014 were surveyed regarding bibliometric data, subjective outcomes and factors considered important in completing their research projects. The other colleges were also approached via email and phone interviews. RESULTS: A records search identified 26 eligible individuals who received 42 grants for 41 projects. The survey response rate was 100%, identifying 33 secondary grants, 65 conference presentations, 10 prizes and 69 publications associated with the FRO grants and consequential research. At least seven higher degrees also resulted. The funding process was very positively perceived by grant recipients, and the two factors identified as most important in project completion were local infrastructure and RANZCR funding. In 2015, FRO allocated AUD$150K for grants compared with $10K-$2.6M from 10 of the other 15 Australasian Medical Colleges. In general, appraisal of funding outcomes relative to expenditure has been only low level until recently. CONCLUSIONS: This project has identified significant research output and subjective benefit from relatively modest FRO seed grants, implying a favourable cost-benefit ratio. Such outcomes monitoring needs to be more widely pursued within Australasian medical colleges.

Combined-modality therapy for primary central nervous system lymphoma: long-term data from a Phase II multicenter study (Trans-Tasman Radiation Oncology Group).

PURPOSE: To assess, in a multicenter setting, the long-term outcomes of a brief course of high-dose methotrexate followed by radiotherapy for patients with primary central nervous system lymphoma (PCNSL). METHODS AND MATERIALS: Forty-six patients were entered in a Phase II protocol consisting of methotrexate (1 g/m(2) on Days 1 and 8), followed by whole-brain irradiation (45-50.4 Gy). The median follow-up time was 7 years, with a minimum follow-up of 5 years. RESULTS: The 5-year survival estimate was 37% (+/-14%, 95% confidence interval [CI]), with progression-free survival being 36% (+/-15%, 95% CI), and median survival 36 months. Of the original 46 patients, 10 were alive, all without evidence of disease recurrence. A total of 11 patients have developed neurotoxicity, with the actuarial risk being 30% (+/-18%, 95% CI) at 5 years but continuing to increase. For patients aged>60 years the risk of neurotoxicity at 7 years was 58% (+/-30%, 95% CI). CONCLUSION: Combined-modality therapy, based on high-dose methotrexate, results in improved survival outcomes in PCNSL. The risk of neurotoxicity for patients aged>60 years is unacceptable with this regimen, although survival outcomes for patients aged>60 years were higher than in many other series.

Whole brain irradiation following surgery or radiosurgery for solitary brain metastases: mature results of a prematurely closed randomized Trans-Tasman Radiation Oncology Group trial (TROG 98.05).

We evaluated the effect of adjuvant whole brain irradiation (WBI) after surgery or radiosurgery for solitary brain metastases in a Phase III multicentre trial with randomization to 30-36 Gy WBI or observation. The study was closed early due to slow accrual after 19 patients (WBI 10, observation 9). There was no difference in CNS failure-free survival or overall survival between the arms. There was a trend to reduced CNS relapse with WBI (30% versus 78%, P=0.12). Limited analysis of quality of life and neurocognitive function data revealed no evidence of difference between the arms. Our results are not inconsistent with two larger randomized trials and support the use of upfront WBI to decrease brain recurrence in this setting.

Costing the components of pain management: analysis of Trans-Tasman Radiation Oncology Group trial (TROG 96.05): one versus five fractions for neuropathic bone pain.

BACKGROUND AND PURPOSE: Bone metastases causing neuropathic pain (NBP) have traditionally been treated with fractionated radiotherapy (RT). A recently reported randomised Trans-Tasman Radiation Oncology Group trial (TROG 96.05) supports this approach in many cases [Roos DE, Turner SL, O'Brien PC et al. Randomised trial of 8 Gy in 1 versus 20 Gy in 5 fractions of radiotherapy for neuropathic pain due to bone metastases (Trans-Tasman Radiation Oncology Group, TROG 96.05). Radiother Oncol 2005;75:54-63]. This study sought to compare costs to the Australian health-care system for patients receiving 1 versus 5 fractions for NBP. PATIENTS AND METHODS: The RT and medication costs for 245 patients treated on TROG 96.05 were determined from trial data out to 3 months from RT. Admission costs and causes were derived from hospital records. RESULTS: RT costs (including re-treatments) were calculated to be 222 and 724 Australian dollars (A dollars) per patient for the 8 Gy/1 and 20 Gy/5 arms, respectively. This difference increased when analgesics (A dollars 192 versus A dollars 229) and related hospital admissions (A dollars 1,411 versus A dollars 1,893) were considered. Sensitivity analysis demonstrated an incremental cost saving of between A dollars 795 and A dollars 1,468 for single fraction RT. Admission rates had the strongest potential to distort cost differences. CONCLUSIONS: Clinical outcomes are paramount in choice of fractionation scheme but are optimally considered in the light of economic implications. Overall cost differences between fractionation schedules may vary greatly from those incurred by the RT treatment centre alone. Ideally, such economic evaluations should be planned at the outset of a trial.

Randomized trial of 8 Gy in 1 versus 20 Gy in 5 fractions of radiotherapy for neuropathic pain due to bone metastases (Trans-Tasman Radiation Oncology Group, TROG 96.05).

BACKGROUND AND PURPOSE: Despite numerous randomized trials investigating radiotherapy (RT) fractionation schedules for painful bone metastases, there are very few data on RT for bone metastases causing pain with a neuropathic component. The Trans-Tasman Radiation Oncology Group undertook a randomized trial comparing the efficacy of a single 8 Gy (8/1) with 20 Gy in 5 fractions (20/5) for this type of pain. MATERIALS AND METHODS: Eligible patients had radiological evidence of bone metastases from a known malignancy with no change in systemic therapy within 6 weeks before or anticipated within 4 weeks after RT, no other metastases along the distribution of the neuropathic pain and no clinical or radiological evidence of cord/cauda equina compression. All patients gave written informed consent. Primary endpoints were pain response within 2 months of commencement of RT and time to treatment failure (TTF). The hypothesis was that 8/1 is at least as effective as 20/5 and the planned sample size was 270 patients. RESULTS: Between February 1996 and December 2002, 272 patients were randomized (8/1:20/5=137:135) from 15 centres (Australia 11, New Zealand 3, UK 1). The commonest primary cancers were lung (31%), prostate (29%) and breast (8%); index sites were spine (89%), rib (9%), other (2%); 72% of patients were males and the median age was 67 (range 29-89). The median overall survival (95% CI) for all randomized patients was 4.8 mo (4.2-5.7 mo). The intention-to-treat overall response rates (95% CI) for 8/1 vs 20/5 were 53% (45-62%) vs 61% (53-70%), P=0.18. Corresponding figures for complete response were 26% (18-34%) vs 27% (19-35%), P=0.89. The estimated median TTFs (95% CI) were 2.4 mo (2.0-3.3 mo) vs 3.7 mo (3.1-5.9 mo) respectively. The hazard ratio (95% CI) for the comparison of TTF curves was 1.35 (0.99-1.85), log-rank P=0.056. There were no statistically significant differences in the rates of re-treatment, cord compression or pathological fracture by arm. CONCLUSIONS: 8/1 was not shown to be as effective as 20/5, nor was it statistically significantly worse. Outcomes were generally poorer for 8/1, although the quantitative differences were relatively small.

Radiotherapy for neuropathic pain due to bone metastases.

Neuropathic bone pain (NBP) due to bone metastases is estimated to affect about 15-25% of cancer patients experiencing pain. Numerous randomized trials have shown that single or multiple fraction radiotherapy (RT) for painful bone metastases produces intention-to-treat overall response rates (RRs) of approximately 60%, but there are few data on RT for NBP, per se. One randomized trial, Trans Tasman Radiation Oncology Group (TROG) 96.05 showed similar outcomes for NBP, although a single 8 Gy fraction was not proven to be as effective as fractionated treatment (20 Gy in five fractions), with RRs of 53% and 61%, respectively. A recent small, single institution series reported a comparable overall RR for NBP using a variety of fractionation schedules. Although TROG 96.05 found no statistically significant difference in the rates of re-treatment, spinal cord compression, or pathological fracture at the index site by arm, one subsequent single institution retrospective review cautioned against using single fractions for spine (the skeletal site causing the vast majority of NBP), particularly in the presence of high "spinal instability" scores. In that study, single fractions were associated with more spinal adverse events (including symptomatic vertebral compression fracture and spinal cord compression) than fractionated schedules. Although re-irradiation of bone metastases is feasible and moderately effective, there are no outcome data specific to re-treatment of NBP. In summary, NBP may appropriately be treated with fractionated RT, although single fractions may also be reasonable for patients with poor performance status and/or limited expected survival, and in centers with prolonged waiting times for fractionated treatment, given that re-treatment is possible for either. In addition, multiple fractions may be preferable for vertebral metastases in the setting of high "spinal instability" risk.

Quality indicators for prostate radiotherapy: are patients disadvantaged by receiving treatment in a 'generalist' centre?

INTRODUCTION: The purpose of this retrospective review was to evaluate concordance with evidence-based quality indicator guidelines for prostate cancer patients treated radically in a 'generalist' (as distinct from 'sub-specialist') centre. We were concerned that the quality of treatment may be lower in a generalist centre. If so, the findings could have relevance for many radiotherapy departments that treat prostate cancer. METHODS: Two hundred fifteen consecutive patients received external beam radiotherapy (EBRT) and/or brachytherapy between 1.10.11 and 30.9.12. Treatment was deemed to be in line with evidence-based guidelines if the dose was: (i) 73.8-81 Gy at 1.8-2.0 Gy/fraction for EBRT alone (eviQ guidelines); (ii) 40-50 Gy (EBRT) for EBRT plus high-dose rate (HDR) brachytherapy boost (National Comprehensive Cancer Network (NCCN) guidelines); and (iii) 145 Gy for low dose rate (LDR) I-125 monotherapy (NCCN). Additionally, EBRT beam energy should be ≥6 MV using three-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT), and high-risk patients should receive neo-adjuvant androgen-deprivation therapy (ADT) (eviQ/NCCN). Treatment of pelvic nodes was also assessed. RESULTS: One hundred four high-risk, 84 intermediate-risk and 27 low-risk patients (NCCN criteria) were managed by eight of nine radiation oncologists. Concordance with guideline doses was confirmed in: (i) 125 of 136 patients (92%) treated with EBRT alone; (ii) 32 of 34 patients (94%) treated with EBRT + HDR BRT boost; and (iii) 45 of 45 patients (100%) treated with LDR BRT alone. All EBRT patients were treated with ≥6 MV beams using 3D-CRT (78%) or IMRT (22%). 84%, 21% and 0% of high-risk, intermediate-risk and low-risk patients received ADT, respectively. Overall treatment modality choice (including ADT use and duration where assessable) was concordant with guidelines for 176/207 (85%) of patients. CONCLUSION: The vast majority of patients were treated concordant with evidence-based guidelines suggesting that, within the limits of the selected criteria, prostate cancer patients are unlikely to be disadvantaged by receiving radiotherapy in this 'generalist' centre.

When is an acoustic neuroma not an acoustic neuroma? Pitfalls for radiosurgeons.

INTRODUCTION: Because acoustic neuroma (AN), also termed vestibular schwannoma, constitutes by far the commonest intracranial schwannoma and cerebello-pontine angle (CPA) tumour, there is a risk of overlooking rarer alternative diagnoses with similar clinical and/or radiological features. The purpose of this article is to highlight to radiosurgeons the potentially serious implications of this problem through illustrative case studies. METHODS: Our linac stereotactic radiosurgery (SRS) technique has been previously described, with stereotactic headring fixation and treatment delivered via cones or micro-multileaf collimators using multiple arcs or static beams. RESULTS: Between November 1993 and October 2014, we treated 132 patients referred with a clinical diagnosis of AN, the vast majority with 12 Gy marginal dose. Three of these (2.3%), evident either at the time of treatment (2) or subsequently (1), had features instead consistent with cochlear schwannoma, facial schwannoma and meningioma, respectively. Each warranted significant modification to standard AN outlining and fields. The meningioma progressed due to geographic miss. One other patient with recurrent facial schwannoma (not yet needing SRS) was also referred with an incorrect diagnosis of AN. CONCLUSION: When rare variants of common medical problems are not identified before referral, there is a risk that 'blinkering' can lead to misdiagnosis and suboptimal treatment. Radiosurgeons need to be particularly mindful of this issue with AN, which can mimic several other tumours occurring in the CPA region, albeit with different patterns of spread. Optimal imaging, high-quality radiology reporting and neuroradiology input at the time of SRS planning within the setting of a specialised multidisciplinary team are highly desirable.

Evidence for efficacy without increased toxicity of hypofractionated radiotherapy for prostate carcinoma: early results of a Phase III randomized trial.

PURPOSE: We performed a randomized trial to compare the GI and urogenital toxicity of radiotherapy (RT) for localized (confined to the organ), early-stage (T1-T2N0M0, TNM classification) carcinoma of the prostate, using a conventional (64 Gy in 32 fractions within 6.5 weeks) vs. a hypofractionated (55 Gy in 20 fractions within 4 weeks) schedule and to determine the efficacy of the respective treatment schedules. METHODS AND MATERIALS: This report is based on an interim analysis of the first 120 consecutive patients in this Phase III trial after a median follow-up of 43.5 months (range 23-62). RT planning was based on two-dimensional CT data, and the treatment was delivered using a three- or four-field 6-23-MV photon technique. GI and urogenital toxicity (symptom questionnaires incorporating the subjective elements of the late effects of normal tissues-subjective, objective, management, analytic classification of late effects and the European Organization for Research and Treatment of Cancer sexual function questionnaire) were evaluated before RT and 1 month, 1 year, and 2 years after RT completion. The efficacy of RT was assessed clinically (digital rectal examination and radiologic imaging) and biochemically (prostate-specific antigen assay) at baseline, and every 3 months for 2 years after RT and every 6 months subsequently. RESULTS: RT, whether conventional or hypofractionated, resulted in an increase in all six symptom categories used to characterize GI toxicity and in four of five symptom categories used to document urinary morbidity 1 month after therapy completion. Sexual dysfunction (based on limited data), which existed in more than one-third of patients before RT, also increased to just more than one-half of patients 1 month after RT. The increase in urinary toxicity after RT was not sustained (diurnal urinary frequency had decreased significantly at 2 years). In contrast, all six symptom categories of GI toxicity remained increased 1 year after RT. Four of the six GI symptom categories (rectal pain, mucous discharge, urgency of defecation, and rectal bleeding) were still increased at 2 years compared with baseline. Except for a slightly greater percentage of patients experiencing mild rectal bleeding at 2 years among those who received hypofractionated RT, no differences were noted in toxicity between the conventional and hypofractionated RT schedule. The mean prostate-specific antigen level was 14.0 +/- 1.0 ng/mL at baseline and declined to a nadir of 1.3 +/- 0.2 ng/mL at a median of 16.8 months (range 0.8-28.3) after RT completion. However, it then rose in 17 patients (8 in the hypofractionated and 9 in the conventional treatment group). Only 8 of these 17 patients were found to have signs of clinical relapse (5 local, 1 regional lymph node, and 2 systemic [bony metastases]) after histopathologic and radiologic reassessment). The remaining 9 patients had biochemical relapse only (defined as three consecutive rises in prostate-specific antigen after nadir). The 4-year biochemical relapse-free survival rate was 85.8% for all patients and did not differ significantly between the two radiation dose schedules (86.2% for the hypofractionated and 85.5% for the conventional fractionation group). CONCLUSION: RT for prostate carcinoma, using a three- or four-field 6-23-MV photon technique without posterior shielding of the lateral fields, is an underestimated cause of persistent GI morbidity. The incidence of clinically significant GI and urogenital toxicity after conventional and hypofractionated RT appears to be similar. Hypofractionated RT for carcinoma of the prostate seems just as effective as conventional RT after a median follow-up approaching 4 years.

Quality assurance experience with the randomized neuropathic bone pain trial (Trans-Tasman Radiation Oncology Group, 96.05).

BACKGROUND AND PURPOSE: Trans-Tasman Radiation Oncology Group 96.05 is a prospective randomized controlled trial comparing a single 8 Gy with 20 Gy in five fractions of radiotherapy (RT) for neuropathic pain due to bone metastases. This paper summarizes the quality assurance (QA) activities for the first 234 patients (accrual target 270). MATERIALS AND METHODS: Independent audits to assess compliance with eligibility/exclusion criteria and appropriateness of treatment of the index site were conducted after each cohort of approximately 45 consecutive patients. Reported serious adverse events (SAEs) in the form of cord/cauda equina compression or pathological fracture developing at the index site were investigated and presented in batches to the Independent Data Monitoring Committee. Finally, source data verification of the RT prescription page and treatment records was undertaken for each of the first 234 patients to assess compliance with the protocol. RESULTS: Only one patient was found conclusively not to have genuine neuropathic pain, and there were no detected 'geographical misses' with RT fields. The overall rate of detected infringements for other eligibility criteria over five audits (225 patients) was 8% with a dramatic improvement after the first audit. There has at no stage been a statistically significant difference in SAEs by randomization arm. There was a 22% rate of RT protocol variations involving ten of the 14 contributing centres, although the rate of major dose violations (more than +/-10% from protocol dose) was only 6% with no statistically significant difference by randomization arm (P=0.44). CONCLUSIONS: QA auditing is an essential but time-consuming component of RT trials, including those assessing palliative endpoints. Our experience confirms that all aspects should commence soon after study activation.

LINAC radiosurgery for cerebral arteriovenous malformations: a single centre prospective analysis and review of the literature.

Stereotactic radiosurgery (SRS) is a well established, minimally invasive treatment option for patients diagnosed with cerebral arteriovenous malformations (AVM). We present the experience in linear accelerator-based SRS for cerebral AVM treated over 14 years. We prospectively followed 67 patients with 69 AVM treated with SRS from 1994 to 2008, inclusive. The mean patient age was 37 years (range 7-69) with 36 women and 31 men. The median AVM size, as defined by maximal diameter, was 2.5 cm (range 0.5-4.6 cm) and the median marginal dose was 18 Gy in one fraction. The crude angiographic obliteration rate was 55% with a 3 and 5 year actuarial rate of 39% and 65%, respectively. Median time to obliteration was 4.2 years. Higher treatment dose (p<0.0001) and smaller maximal AVM diameter (p=0.002) were associated with an increased obliteration rate. There were no deaths from treatment. Post-treatment neurological complications occurred in 10 patients (15%) including hemorrhage in two. Twelve patients (18%) required a second SRS procedure. Larger AVM diameter was associated with increased odds of requiring re-treatment (p=0.02). Radiosurgery for intracerebral AVM is a non-invasive therapeutic option with low morbidity and a reasonable likelihood of nidus obliteration. Treatment dose and AVM diameter are the main determinants of obliteration.