Miriam M Boxer

Do multidisciplinary team meetings make a difference in the management of lung cancer

There is limited evidence regarding the effectiveness of multidisciplinary team (MDT) meetings in lung cancer. The objective of this study was to compare the patterns of care for patients with newly diagnosed lung cancer who were presented at a lung cancer MDT meeting with the patterns of care for patients who were not presented.

Impact of a real-time peer review audit on patient management in a radiation oncology department.

In September 2006, the Royal Australian and New Zealand College of Radiologists (RANZCR) endorsed the modified Peer Review Audit Tool (PRAT). We aimed to assess the feasibility of using this tool in a busy radiation oncology department using an electronic medical record (EMR) system, identify areas of compliance and assess the impact of the audit process on patient management. Fortnightly random clinical audit was undertaken by using the revised RANZCR PRAT in the departments of radiation oncology at Liverpool and Macarthur Cancer Therapy Centres (LCTC and MCTC). Following audit of the EMR, treatment plans were audited by peer review. Data were collected prospectively from June 2007 to June 2008. Audits were carried out on 208 patients. Behaviour criteria were well documented in the EMR, but scanning of histology and medical imaging reports did not occur in up to a third of cases. With electronic prescriptions, treatment prescription errors were rare. In total, 8 (3.8%) out of 208 patients had a change to management recommended. Variability in interpretation of PRAT ‘protocol/study’ criteria was identified. We found that real‐time audit is feasible and effective in detecting both issues with documentation in the EMR, and a small number of patients in whom a change to management is recommended. Recommendations have been made in order to continue to improve the audit process including documentation of any changes recommended and whether the recommended change occurred.

Australian survey on current practices for breast radiotherapy

Detailed, published surveys specific to Australian breast radiotherapy practice were last conducted in 2002. More recent international surveys specific to breast radiotherapy practice include a European survey conducted in 2008/2009 and a Spanish survey conducted in 2009. Radiotherapy techniques continue to evolve, and the utilisation of new techniques, such as intensity‐modulated radiation therapy (IMRT), is increasing. This survey aimed to determine current breast radiotherapy practices across Australia.

A review of the management of ductal carcinoma in situ following breast conserving surgery

Ductal carcinoma in situ (DCIS) is a heterogeneous, pre-malignant disease accounting for 10-20% of all new breast tumours. Evidence shows a statistically significant local control benefit for adjuvant radiotherapy (RT) following breast conserving surgery (BCS) for all patients. The baseline recurrence risk of individual patients varies according to clinical-pathological criteria and in selected patients, omission of RT may be considered, following a discussion with the patient. The role of adjuvant endocrine therapy remains uncertain. Ongoing studies are attempting to define subgroups of patients who are at sufficiently low risk of recurrence that RT may be safely omitted; investigating RT techniques and dose fractionation schedules; and defining the role of endocrine therapy. Future directions in the management of patients with DCIS will include investigation of prognostic and predictive biomarkers to inform individualised therapy tailored to the risk of recurrence.

MRI geometric distortion: Impact on tangential whole-breast IMRT

The purpose of this study was to determine the impact of magnetic resonance imaging (MRI) geometric distortions when using MRI for target delineation and planning for whole‐breast, intensity‐modulated radiotherapy (IMRT). Residual system distortions and combined systematic and patient‐induced distortions are considered. This retrospective study investigated 18 patients who underwent whole‐breast external beam radiotherapy, where both CT and MRIs were acquired for treatment planning. Distortion phantoms were imaged on two MRI systems, dedicated to radiotherapy planning (a wide, closed‐bore 3T and an open‐bore 1T). Patient scans were acquired on the 3T system. To simulate MRI‐based planning, distortion maps representing residual system distortions were generated via deformable registration between phantom CT and MRIs. Patient CT images and structures were altered to match the residual system distortion measured by the phantoms on each scanner. The patient CTs were also registered to the corresponding patient MRI scans, to assess patient and residual system effects. Tangential IMRT plans were generated and optimized on each resulting CT dataset, then propagated to the original patient CT space. The resulting dose distributions were then evaluated with respect to the standard clinically acceptable DVH and visual assessment criteria. Maximum residual systematic distortion was measured to be 7.9 mm (95%<4.7mm) and 11.9 mm (95%<4.6mm) for the 3T and 1T scanners, respectively, which did not result in clinically unacceptable plans. Eight of the plans accounting for patient and systematic distortions were deemed clinically unacceptable when assessed on the original CT. For these plans, the mean difference in PTV V95 (volume receiving 95% prescription dose) was 0.13±2.51% and −0.73±1.93% for right‐ and left‐sided patients, respectively. Residual system distortions alone had minimal impact on the dosimetry for the two scanners investigated. The combination of MRI systematic and patient‐related distortions can result in unacceptable dosimetry for whole‐breast IMRT, a potential issue when considering MRI‐only radiotherapy treatment planning. PACS number(s): 87.61.‐c, 87.57.cp, 87.57.nj, 87.55.D‐

Safety of carbon dioxide as a contrast medium in cerebral angiography

An increasing number of studies report the safety and effectiveness of carbon dioxide (CO2) as a digital subtraction angiographic contrast agent for intraarterial use below the diaphragm. Concerns about the possible neurotoxic effects of CO 2 within the cerebral circulation may be hindering its more widespread use below the diaphragm, because of the potential for reflux into the brain due to its buoyancy. These same concerns have also suppressed any consideration of CO 2 as a potential contrast agent for cerebral angiography. These concerns have been supported by a study (1) in which rats received single intracarotid injections of CO 2 in a range of doses, causing irreversible blood-brain barrier (BBB) damage and severe neurological deficits, with death occurring within 24 hours at the higher doses. Multifocal ischemic infarction was observed histologically as early as 6 hours after injection (1). Conversely, in a more recent study, dogs received multiple aortic arch and intracarotid injections of CO 2 but showed no EEG changes, no neurological deficits up to 6 months later, and no macroscopic pathological brain changes (2). There is clearly conflicting evidence about the safety of CO 2 within the cerebral circulation, and this investigation was undertaken with the intention of resolving the issue. Short-term studies were undertaken to determine the effects of intracarotid CO 2 on the BBB, and medium-term

Hypofractionated versus conventionally fractionated radiotherapy for ductal carcinoma in situ (DCIS) of the breast

Hypofractionated radiotherapy (RT) in the setting of early invasive breast cancer has been shown to have similar local control rates and cosmetic outcomes as conventionally fractionated RT. This study compares ipsilateral recurrence rates between hypofractionated and conventional RT, with and without a boost. The effect of hypofractionated RT and chest wall separation (CWS) on cosmetic outcome was also assessed.

Do patients discussed at a lung cancer multidisciplinary team meeting receive guideline-recommended treatment?

Clinical guidelines provide evidence‐based management recommendations to guide practice. This study aimed to evaluate whether patients discussed at a lung cancer multidisciplinary team meeting received guideline‐recommended treatment and determine reasons for not receiving guideline‐recommended treatment.

Assessment of MRI image quality for various setup positions used in breast radiotherapy planning

This study investigates breast magnetic resonance imaging (MRI) image quality for 3 different breast radiotherapy positions (prone, supine flat and supine inclined) and associated choice of breast coils. Supine breast MRI has comparable image quality to prone breast MRI for the purposes of radiotherapy delineation for T2-weighted sequences.

The toxic effects of angiographic carbon dioxide in the cerebral vasculature

Carbon dioxide (CO2) gas has been used clinically as an arterial contrast medium for more than 25 years. It has a number of advantages over iodinated contrast media, including its low cost, low viscosity, rapid elimination, buoyancy, and lack of nephrotoxic and allergic effects (1). Its disadvantages include the need to avoid air contamination and to use a dedicated injector system. When properly delivered and imaged, it produces images comparable to iodinated contrast media, and it is currently in use in all areas where iodinated contrast media are used, with the exception of the cerebral arterial vasculature (1). This exception is the result of concerns about the neurotoxicity of carbon dioxide in the cerebral vasculature. These concerns are based on animal studies showing severe neurotoxicity of carbon dioxide injected into the cerebral vasculature (2,3). Other animal studies, on the other hand, have been unable to demonstrate any neurotoxicity of carbon dioxide (1,4,5). Interpretation of these conflicting studies is complicated by the fact that most of them have not employed a systematic experimental approach, using different volumes, pressures, injection numbers, and injection sites within the same experiment. There are also concerns that, in some cases, the observation of neurotoxicity may have been influenced by air contamination and by high-pressure, explosive delivery of large volumes of carbon dioxide (1). It has been shown in this laboratory that multiple, nonexplosive internal carotid injections of carbon dioxide at clinically relevant doses in rabbits cause blood–brain barrier (BBB) breakdown that is still present 30 minutes later (6). This study was undertaken to investigate the reversibility of this BBB breakdown, and to examine brains for evidence of histologic damage 6 hours after multiple internal carotid injections of carbon dioxide delivered as reproducibly and benignly as possible. It is necessary to resolve the question of the neurotoxicity of carbon dioxide to determine both whether it is a safe neuroangiographic contrast medium and whether there is cause for concern about possible incidental reflux into the cerebral vasculature during carbon dioxide angiography below the diaphragm.