Assessment of Optimizers and their Performance in Autosegmenting Lung Tumors

Purpose

Optimizers are widely utilized across various domains to enhance desired outcomes by either maximizing or minimizing objective functions. In the context of deep learning, they help to minimize the loss function and improve model's performance. This study aims to evaluate the accuracy of different optimizers employed for autosegmentation of non-small cell lung cancer (NSCLC) target volumes on thoracic computed tomography images utilized in oncology.

Materials and Methods

The study utilized 112 patients, comprising 92 patients from "The Cancer Imaging Archive" (TCIA) and 20 of our local clinical patients, to evaluate the efficacy of various optimizers. The gross tumor volume was selected as the foreground mask for training and testing the models. Of the 92 TCIA patients, 57 were used for training and validation, and the remaining 35 for testing using nnU-Net. The performance of the final model was further evaluated on the 20 local clinical patient datasets. Six different optimizers, namely AdaDelta, AdaGrad, Adam, NAdam, RMSprop, and stochastic gradient descent (SGD), were investigated. To assess the agreement between the predicted volume and the ground truth, several metrics including Dice similarity coefficient (DSC), Jaccard index, sensitivity, precision, Hausdorff distance (HD), 95th percentile Hausdorff distance (HD95), and average symmetric surface distance (ASSD) were utilized.

Results

The DSC values for AdaDelta, AdaGrad, Adam, NAdam, RMSprop, and SGD were 0.75, 0.84, 0.85, 0.84, 0.83, and 0.81, respectively, for the TCIA test data. However, when the model trained on TCIA datasets was applied to the clinical datasets, the DSC, HD, HD95, and ASSD metrics showed a statistically significant decrease in performance compared to the TCIA test datasets, indicating the presence of image and/or mask heterogeneity between the data sources.

Conclusion

The choice of optimizer in deep learning is a critical factor that can significantly impact the performance of autosegmentation models. However, it is worth noting that the behavior of optimizers may vary when applied to new clinical datasets, which can lead to changes in models' performance. Therefore, selecting the appropriate optimizer for a specific task is essential to ensure optimal performance and generalizability of the model to different datasets.

Investigation of Computed Tomography Numbers on Multiple Imaging Systems using Single and Multislice Methods

Aim

The aim of this study is to determine the variation in Hounsfield values with single and multi-slice methods using in-house software on fan-beam computed tomography (FCT), linear accelerator (linac) cone-beam computed tomography (CBCT), and Icon-CBCT datasets acquired using Gammex and advanced electron density (AED) phantoms.

Materials and Methods

The AED phantom was scanned on a Toshiba computed tomography (CT) scanner, five linac-based CBCT X-ray volumetric imaging systems, and Leksell Gamma Knife Icon. The variation between single and multi-slice methods was assessed by comparing scans acquired using Gammex and AED phantoms. The variation in Hounsfield units (HUs) between seven different clinical protocols was assessed using the AED phantom. A CIRS Model 605 Radiosurgery Head Phantom (TED) phantom was scanned on all three imaging systems to assess the target dosimetric changes due to HU variation. An in-house software was developed in MATLAB to assess the HU statistics and the trend along the longitudinal axis.

Results

The FCT dataset showed a minimal variation (central slice ± 3 HU) in HU values along the long axis. A similar trend was also observed between the studied clinical protocols acquired on FCT. Variation among multiple linac CBCTs was insignificant. In the case of the water insert, a maximum HU variation of -7.23 ± 68.67 was observed for Linac 1 towards the inferior end of the phantom. All five linacs appeared to have a similar trend in terms of HU variation from the proximal to the distal end of the phantom, with a few outliers for Linac 5. Among three imaging modalities, the maximum variation was observed in gamma knife CBCTs, whereas FCT showed no appreciable deviation from the central value. In terms of dosimetric comparison, the mean dose in CT and Linac CBCT scans differed by <0.5 Gy, whereas at least a 1 Gy difference was observed between CT and gamma knife CBCT.

Conclusion

This study shows a minimal variation with FCT between single, volume-based, and multislice methods, and hence the current approach of determining the CT-electron density curve based on a single-slice method would be sufficient for producing a HU calibrations curve for treatment planning. However, CBCTs acquired on linac, and in particular, gamma knife systems, show noticeable variations along the long axis, which is likely to affect the dose calculations performed on CBCTs. It is highly recommended to assess the Hounsfield values on multiple slices before using the HU curve for dose calculations.

Automatic Detection and Tracking of Marker Seeds Implanted in Prostate Cancer Patients using a Deep Learning Algorithm

Purpose:

Fiducial marker seeds are often used as a surrogate to identify and track the positioning of prostate volume in the treatment of prostate cancer. Tracking the movement of prostate seeds aids in minimizing the prescription dose spillage outside the target volume to reduce normal tissue complications. In this study, You Only Look Once (YOLO) v2™ (MathWorks™) convolutional neural network was employed to train ground truth datasets and develop a program in MATLAB that can visualize and detect the seeds on projection images obtained from kilovoltage (kV) X-ray volume imaging (XVI) panel (Elekta™).

Methods:

As a proof of concept, a wax phantom containing three gold marker seeds was imaged, and kV XVI seed images were labeled and used as ground truth to train the model. The projection images were corrected for any panel shift using flex map data. Upon successful testing, labeled marker seeds and projection images of three patients were used to train a model to detect fiducial marker seeds. A software program was developed to display the projection images in real-time and predict the seeds using YOLO v2 and determine the centers of the marker seeds on each image.

Results:

The fiducial marker seeds were successfully detected in 98% of images from all gantry angles; the variation in the position of the seed center was within ± 1 mm. The percentage difference between the ground truth and the detected seeds was within 3%.

Conclusion:

Our study shows that deep learning can be used to detect fiducial marker seeds in kV images in real time. This is an ongoing study, and work is underway to extend it to other sites for tracking moving structures with minimal effort.

Partial breast irradiation versus whole breast radiotherapy for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

On 27 August 2020, we searched the Cochrane Breast Cancer Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and three trial databases. We searched for grey literature: OpenGrey (September 2020), reference lists of articles, conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction, used Cochrane's risk of bias tool and resolved any disagreements through discussion, and assessed the certainty of the evidence for main outcomes using GRADE. Main outcomes were local recurrence-free survival, cosmesis, overall survival, toxicity (subcutaneous fibrosis), cause-specific survival, distant metastasis-free survival and subsequent mastectomy. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included nine RCTs that enrolled 15,187 women who had invasive breast cancer or ductal carcinoma in-situ (6.3%) with T1-2N0-1M0 Grade I or II unifocal tumours (less than 2 cm or 3 cm or less) treated with breast-conserving therapy with negative margins. This is the second update of the review and includes two new studies and 4432 more participants. Local recurrence-free survival is probably slightly reduced (by 3/1000, 95% CI 6 fewer to 0 fewer) with the use of PBI/APBI compared to WBRT (hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.03 to 1.42; 8 studies, 13,168 participants; moderate-certainty evidence). Cosmesis (physician/nurse-reported) is probably worse (by 63/1000, 95% CI 35 more to 92 more) with the use of PBI/APBI (odds ratio (OR) 1.57, 95% CI 1.31 to 1.87; 6 studies, 3652 participants; moderate-certainty evidence). Overall survival is similar (0/1000 fewer, 95% CI 6 fewer to 6 more) with PBI/APBI and WBRT (HR 0.99, 95% CI 0.88 to 1.12; 8 studies, 13,175 participants; high-certainty evidence). Late radiation toxicity (subcutaneous fibrosis) is probably increased (by 14/1000 more, 95% CI 102 more to 188 more) with PBI/APBI (OR 5.07, 95% CI 3.81 to 6.74; 2 studies, 3011 participants; moderate-certainty evidence). The use of PBI/APBI probably makes little difference (1/1000 less, 95% CI 6 fewer to 3 more) to cause-specific survival (HR 1.06, 95% CI 0.83 to 1.36; 7 studies, 9865 participants; moderate-certainty evidence). We found the use of PBI/APBI compared with WBRT probably makes little or no difference (1/1000 fewer (95% CI 4 fewer to 6 more)) to distant metastasis-free survival (HR 0.95, 95% CI 0.80 to 1.13; 7 studies, 11,033 participants; moderate-certainty evidence). We found the use of PBI/APBI in comparison with WBRT makes little or no difference (2/1000 fewer, 95% CI 20 fewer to 20 more) to mastectomy rates (OR 0.98, 95% CI 0.78 to 1.23; 3 studies, 3740 participants, high-certainty evidence).

AUTHORS' CONCLUSIONS

It appeared that local recurrence-free survival is probably worse with PBI/APBI; however, the difference was small and nearly all women remain free of local recurrence. Overall survival is similar with PBI/APBI and WBRT, and we found little to no difference in other oncological outcomes. Some late effects (subcutaneous fibrosis) may be worse with PBI/APBI and its use is probably associated with worse cosmetic outcomes. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver PBI/APBI. We await completion of ongoing trials.

Comparison of whole breast dosimetry techniques - From 3DCRT to VMAT and the impact on heart and surrounding tissues

INTRODUCTION

Various techniques for whole breast radiation therapy (WBRT) have been reported to increase dose to contralateral tissues. Heart dose is of critical importance as there is no apparent dose threshold below which there is no risk. The aim of this study was to compare planning techniques for WBRT that achieves the best target dosimetry and lowest organ at risk (OAR) dose.

METHODS

Thirty early-stage whole breast patient datasets, 15 each left- and right-sided cases, were retrospectively selected. Five techniques were generated for each data set: three-dimensional conformal radiation therapy (3DCRT), hybrid intensity modulated radiation therapy (HYI), hybrid volumetric modulated arc therapy (VMAT) - (HYV), reduced arc VMAT - bowtie (BT), and BT flattening filter free (FFF) - (BTFFF). Plan goals and OARs were evaluated and compared between techniques.

RESULTS

BT had the highest median conformity index (CI) values (0.82, IQR: 0.80-0.85 left and 0.83, IQR 0.80-0.86 right). BT recorded lower mean heart doses (median value 1.19Gy, IQR: 0.90-1.55), and BTFFF recorded lower heart V2.5 _Gy , V5 _Gy ; median 3.96% (IQR: 2.90-6.80) and 0.90% (IQR: 0.50-1.50) respectively for left-sided patients. There was a statistically significant difference in all ipsilateral lung measures, (p < 0.001) with BTFFF producing significantly lower doses across all measures: mean, V5 _Gy , V10 _Gy and V20 _Gy .

CONCLUSION

Overall BT and BTFFF techniques produced lower OAR doses and equivalent PTV coverage for WBRT. BT and BTFFF techniques increased contralateral lung and breast doses; however, these were within prescribed tolerances and comparable to results published in the literature.

A prospective evaluation of treatment recommendations compared to outcomes for a lung cancer multidisciplinary team and legal implications

INTRODUCTION

This cross-sectional study compared treatment recommendations made by a respiratory multi-disciplinary team with the treatment received by those patients in practice. The aim was to evaluate the rate at which patients were treated in keeping with MDT recommendations. It was hypothesised that most patients would be treated in accordance with these recommendations. These data were then used to provide a practical basis to consider the potential legal liability of multi-disciplinary teams.

METHODS

All patients discussed in the Princess Alexandra Hospital Lung MDT over a three-month period were included. The recommendations made by the MDT were compared with the treatment received. Where available, the reason for any change in management plan was recorded.

RESULTS

74/109 evaluable patients were treated in accordance with the MDT recommendation. A further 7 patients had commenced treatment prior to MDT discussion. The most common reasons for change in management were patient choice (n = 6) or deterioration in clinical condition prior to treatment (n = 6).

CONCLUSION

As hypothesised, there was a high rate of treatment in accordance with recommendations made by the MDT. Changes in management are mostly related to patient preference or change in condition after MDT discussion. In practice, there are only limited opportunities for an MDT to be liable for patient outcomes. It is suggested however that careful documentation and representation of cases where appropriate could further mitigate this risk.

Identifying breast cancer patients who gain the most dosimetric benefit from deep inspiration breath hold radiotherapy

INTRODUCTION

Deep inspiration breath hold (DIBH) has been proven to reduce cardiac dose for women receiving left breast and chest wall radiation therapy. However, it utilises extra departmental resources and patient exertion. The aim of this exploratory study was to investigate if any factors existed that could identify breast cancer patients who may benefit most from DIBH, to facilitate appropriate utilisation of departmental resources.

METHODS

Left-sided breast cancer patients aged 18-70 years, and right-sided breast cancer patients with internal mammary nodes included, were recruited. DIBH and free breathing (FB) plans were created for all patients. Patient demographic and clinical history were recorded. Variables including lung threshold value, lung volume, patient separation, maximum heart in field, volume of planning target volume (PTV), heart dose, ipsilateral lung dose were compared between plans.

RESULTS

Plans for 31 patients were analysed. No correlations were found between lung threshold value or patient separation and cardiac dose. Moderate to strong correlations were found with BMI, PTV volume and lung volume change however no definitive thresholds were determined. A significant difference was found in the maximum heart in field between DIBH and FB (P < 0.001) with those patients with greater than 0.7 cm heart in the field on the FB scan demonstrating greater reductions in mean heart dose.

CONCLUSION

Maximum heart in the field of greater than 0.7 cm in FB could be a potential factor to identify patients who may benefit most from DIBH. This factor warrants investigation in a larger patient cohort to test its validity.

A Randomized Phase 3 Trial of Palliative Radiation Therapy Versus Concurrent Chemotherapy and Palliative Radiation Therapy in Patients With Good Performance Status, Locally Advanced, or Metastatic Non-Small Cell Lung Cancer With Symptoms due to Intrathoracic Disease Who are Not Suitable for Radical Chemo-radiation Therapy: Results of the Trans-Tasman Radiation Oncology Group 11.03 Trial

PURPOSE

We compared intrathoracic symptom response rate, quality of life (QOL) and toxicity in patients with non-small cell lung cancer (NSCLC) not suitable for radical chemo-radiation therapy, experiencing symptoms from intrathoracic disease, who were randomized to receive palliative radiation therapy (PRT_36/12) or concurrent chemotherapy and PRT (C-PRT_40/20).

METHODS AND MATERIALS

We included patients with stage III or IV NSCLC, with a Eastern Cooperative Oncology Group Performance status 0 to 1, who were experiencing at least one of the following: dyspnea, cough, hemoptysis, or chest pain. The primary outcome was a change in intrathoracic response rate from baseline to 6 weeks post completion of therapy using (1) a composite measure, the Intrathoracic Symptom Burden Index(ISBI), and (2) individual symptom scores measured by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) and Quality of Life Questionnaire - Lung Cancer 13 item (QLQ-LC 13) instruments.

RESULTS

Seventy-six patients were recruited with 68 eligible for analysis. In addition, 42.6% and 57.4% had stage III and IV disease, respectively. The Intrathoracic Symptom Burden Index was significantly lower at 6 weeks posttreatment than at baseline (adjusted mean difference -8.77, standard error 2.67; 95% confidence interval, -13.97% to -3.58%; P < .01) for the entire cohort with no difference between trial arms (P = .34). Both treatments provided effective palliation of individual symptoms with no significant difference between trial arms. QOL during treatment was significantly better for patients receiving C-PRT_(40/20). There was no difference between arms in overall QOL between baseline and 6 weeks posttreatment. There was no difference in toxicity between treatment arms during treatment nor between baseline and 6 weeks posttreatment. There was no difference in progression-free survival. A nonstatistically significant 3-month improvement in median survival favored C-PRT_(40/20).

CONCLUSION

PRT_(36/12) and C-PRT_(40/20) provide effective symptom palliation in patients with stage III NSCLC not suitable for radical chemo-radiation therapy and in patients with stage IV disease. Chemotherapy added to PRT_(40/20) does not provide superior symptomatic relief in this patient cohort.

Incidence of hippocampal metastases in non-small-cell lung cancer

OBJECTIVES

Patients with locally advanced non-small-cell lung cancer (LA-NSCLC) develop brain metastases in 25-50% of cases during the course of their disease. Data on the incidence of metastases occurring in the hippocampus/perihippocampal zones are limited. This is important when considering hippocampal-sparing brain radiation (HS-BR), a method that could potentially reduce the neurocognitive impact of such treatment. The aim of this study was to assess the incidence of hippocampal/perihippocampal metastases in a cohort of patients with advanced NSCLC treated at our institution.

METHODS

This retrospective cohort study included NSCLC patients discussed at our institutional lung cancer multidisciplinary meeting between 2000 and 2016. MRI and contrast-enhanced CT (ceCT) brain images were reviewed to assess the incidence of hippocampal/perihippocampal metastases including metastases within the hippocampal subgranular zone and a 5 mm margin (hippocampal avoidance region) defined as per the RTOG 0933 study.

RESULTS

Of 2146 patients reviewed, 357 (16.6%) had brain metastases. A total of 335 patients had available MRI/ceCT brain images for review. Thirty (9%) patients had brain metastases in the hippocampal avoidance region, 8 (2.4%) with hippocampal metastases and 22 (6.6%) with perihippocampal metastases. Univariate analyses did not show an association between developing metastases in the hippocampal avoidance region and age (P = 0.75), gender (P = 0.91) and tumour type (P = 0.298).

CONCLUSION

The incidence of metastases in the hippocampal avoidance region in our large cohort of patients was 9%. With low rates of metastases in this region, HS-BR can be considered a feasible option in the management of patients with advanced NSCLC.

The clinical efficacy of PSMA PET/MRI in biochemically recurrent prostate cancer compared with standard of care imaging modalities and confirmatory histopathology: results of a single-centre, prospective clinical trial

Prospective evidence for the clinical role and efficacy of prostate specific membrane antigen (PSMA) positron emission tomography (PET)/magnetic resonance imaging (MRI) combining MRI characterization and localization of lesions with PET avidity in comparison to conventional imaging is limited. In a prospective clinical trial, we aimed to evaluate the diagnostic yield and therapeutic impact of PSMA PET/MRI in men with biochemical recurrence (BCR) following curative therapy. A single-centre, prospective clinical trial at the Princess Alexandra Hospital recruited 30 patients with BCR. Patients underwent PSMA PET/MRI and concurrent conventional CT chest, abdomen, pelvis and whole-body bone scan. Biopsy was performed when safety possible for histological correlation of identified lesions. Clinical efficacy and impact of PSMA PET findings were evaluated. 30 patients with BCR were recruited (median PSA 0.69 ng/ml). PSMA avid lesions were present in 21 patients (70%). 23 patients were previously treated with definitive surgery, 6 patients received external beam radiotherapy and 1 patient had low dose rate brachytherapy. A total of 8 of 9 lesions biopsied were positive (88.9% histological correlation). PSMA PET/MRI detected local recurrence (p = 0.005) and pelvic lesions (p = 0.06) more accurately than conventional imaging. PSMA PET/MRI may be useful in staging men with biochemical recurrence, especially when PSA is low. Our data demonstrates a high detection rate, especially for locally recurrent disease, and highlights the role of this modality when PSA is low. This modality has the potential to significantly improve prostate cancer detection and may have implications for earlier salvage treatment, avoidance of futile local therapy and change patient management to lead to improved outcomes.

Radiation therapy for augmenting the efficacy of immunotherapy in advanced non-small cell lung cancer: a case-controlled study

This study investigated the effects of previous radiation therapy on outcomes from nivolumab in advanced NSCLC, and found that previous radiation therapy resulted in significantly higher survival in patients treated with nivolumab for advanced NSCLC http://bit.ly/3btOFSL.

Prior or concurrent radiotherapy and nivolumab immunotherapy in non-small cell lung cancer

BACKGROUND

Studies suggest that combining radiotherapy (RT) with programmed cell death protein 1 (PD-1) blockade may elicit a synergistic antitumor response. We aimed to assess whether prior or concurrent RT was associated with improved disease control in patients with metastatic non-small cell lung cancer (NSCLC) treated with nivolumab.

METHODS

We conducted a retrospective study of patients receiving nivolumab as second or subsequent line therapy for metastatic NSCLC. Patients were categorized into those who received any RT for NSCLC prior to or during nivolumab therapy, and those with no history of RT for NSCLC.

RESULTS

A total of 85 patients received nivolumab between July 2015 and December 2016 and were followed up for a median of 15 months. Sixty-five patients (76.4%) received RT prior to or during nivolumab and 20 patients (23.6%) received nivolumab alone. Baseline characteristics of age, performance status, histology, smoking status and previous therapy were similar between the two groups. Prior or concurrent RT was associated with a superior PFS, median 2.8 months with RT versus 1.3 months without RT (Hazard Ratio (HR) = 0.494; 95% Confidence Interval (CI), 0.279-0.873; P = 0.02). The median OS of the group receiving RT was 6.4 months versus 4.2 months for the no RT group (P = 0.20). RT was not associated with an increase in toxicity.

CONCLUSION

RT prior to or concurrent with nivolumab for metastatic NSCLC was associated with a modest improvement in PFS over nivolumab alone with no evidence of increase in adverse effects. RT may potentiate the effect of anti-PD-1 immunotherapy in NSCLC.

Deep inspiration breath hold in breast cancer: Development and analysis of a patient experience questionnaire

INTRODUCTION

Evidence that Deep Inspiration Breath Hold (DIBH) can reduce cardiac dose during left-sided breast radiation therapy (RT) has led to widespread uptake of this technology. There is a paucity of published information documenting the impact of this technique on the patient's treatment experience. The aim of this study was to develop a tool to assess the patient's experience with the introduction of DIBH using the Elekta^® Active Breathing Coordinator (ABC) in a single institution.

METHODS

A patient experience questionnaire was developed and was completed at three different stages of the patient's treatment; at planning, during the second week of treatment (day 6-10) and during the final week of treatment.

RESULTS

Questionnaire data were collected from 30 patients, who underwent DIBH breast treatment during the period March 2016 to May 2017. Patients were very happy with their use of the ABC equipment and most felt they were well supported and informed during their treatment. Levels of general fatigue and personal anxiety were identified to significantly increase from planning to the conclusion of treatment (P = 0.002 and P < 0.001 respectively).

CONCLUSIONS

This study produced a useful tool to measure patient experience during DIBH treatment. It demonstrated that the use of the technique was acceptable to patients and did not increase their distress. It provided a compelling case for the provision of tailored, well-communicated information, consistent routine and emotional support for patients throughout their entire treatment. The tool could be employed to assess the patient experience as new technologies are introduced into RT.

A Comparison of Non-coplanar Three-dimensional Conformal Radiation Therapy, Intensity Modulated Radiation Therapy, and Volumetric Modulated Radiation Therapy for the Delivery of Stereotactic Ablative Radiation Therapy to Peripheral Lung Cancer

AIM

The objective of the study was to compare three noncoplanar delivery techniques (three-dimensional conformal radiation therapy [3DCRT], intensity-modulated radiation therapy [IMRT], and volumetric-modulated arc therapy [VMAT]) for the delivery of lung stereotactic ablative radiation therapy to peripheral lung tumours.

METHODS AND MATERIALS

The plans were compared by assessing the planning target volume coverage, doses to organs at risk, high and intermediate dose constraints (D_2cm and R_50%) and delivery times using analysis of variance for repeated measurements or Friedman's test when appropriate.

RESULTS

Mean PTV54 Gy coverage was found to be 95.6%, 95.7%, and 95.6% for the 3DCRT, IMRT, and VMAT techniques, respectively. No deviations to the intermediate dose constraints were found in 65%, 65%, and 85% of the patients for the 3DCRT, IMRT, and VMAT plans, respectively. Mean treatment times (excluding setup and imaging) were 20.0 minutes (±1.67), 25.2 minutes (±2.15), and 11.7 (±2.0) minutes respectively for 3DCRT, IMRT, and VMAT.

CONCLUSION

A noncoplanar VMAT technique was found to provide superior intermediate dose sparing with comparable prescription dose coverage when compared with noncoplanar 3DCRT or IMRT. In addition, VMAT was found to reduce the treatment times of stereotactic ablative radiation therapy delivery for peripheral lung tumours.

Radiation oncology directors of training survey 2016: Perspectives and challenges

INTRODUCTION

This paper reports the key findings of the first survey of Australian and New Zealand Radiation Oncology Directors of Training (DoTs) dealing with their perspectives, experiences and challenges.

METHODS

The survey was conducted in September 2016 using a 34-question instrument. It was emailed to all radiation oncology DoTs listed on the Royal Australian and New Zealand College of Radiologists (RANZCR) database. The questions related to demographics, protected time, weekly activities, support, the value of curriculum assessments, challenges and suggested improvements. Respondents were assured that their responses were anonymous.

RESULTS

The response rate was 59.6% (31/52). The median age of respondents was in the 41 to 45 age bracket, but nearly one quarter were over 45 years of age. The median time respondents had been in the role was three to five years (range <0.5 to >10) with the median number of trainees supervised being four (range 1-8). Thirty-five percent had a co DoT. DoTs spent a median of three hours per week on the role (range <1 to >8) with most respondents (67.7%) requiring time during and out of work performing the role, but ten percent claimed it was done out of hours only. Nearly all DoTs were aware they should have protected time, but only just half received it. The educational aspects of training dominated weekly activities, but rostering, specific trainee issues and administration were also featured. Time issues were the greatest challenge for respondents with clinical assignments the most challenging assessment. However, more emphasis on contouring and planning was thought to be required. All DoTs found the dedicated DoT workshops useful, but felt future discussions on trainees in difficulty could be emphasized. The vast majority felt supported by their training site and the College. All respondents believed in the role with most having an interest in educational activities. The majority of respondents (85%) intended to continue in the role for the next 1 to 2 years, but this dropped to 45% when asked about continuing for 5 years.

CONCLUSIONS

This survey of predominantly experienced DoTs, indicated that the role was deemed to be of value in delivering optimal training. The most significant challenges faced by DoTs were finding sufficient time to deal with the responsibilities of the role and dealing with underperforming trainees. Feedback on the currently employed work based assessments will be considered as FRO transitions into programmatic assessment. Furthermore, a desire for training in how to deal with trainees in difficulty, underperforming or unsuitable trainees is noted. Future work is planned following refinements of the survey instrument; and, will also explore stress and burnout in the DoT cohort.

Vector-model-supported optimization in volumetric-modulated arc stereotactic radiotherapy planning for brain metastasis

Long planning time in volumetric-modulated arc stereotactic radiotherapy (VMA-SRT) cases can limit its clinical efficiency and use. A vector model could retrieve previously successful radiotherapy cases that share various common anatomic features with the current case. The prsent study aimed to develop a vector model that could reduce planning time by applying the optimization parameters from those retrieved reference cases. Thirty-six VMA-SRT cases of brain metastasis (gender, male [n = 23], female [n = 13]; age range, 32 to 81 years old) were collected and used as a reference database. Another 10 VMA-SRT cases were planned with both conventional optimization and vector-model-supported optimization, following the oncologists' clinical dose prescriptions. Planning time and plan quality measures were compared using the 2-sided paired Wilcoxon signed rank test with a significance level of 0.05, with positive false discovery rate (pFDR) of less than 0.05. With vector-model-supported optimization, there was a significant reduction in the median planning time, a 40% reduction from 3.7 to 2.2 hours (p = 0.002, pFDR = 0.032), and for the number of iterations, a 30% reduction from 8.5 to 6.0 (p = 0.006, pFDR = 0.047). The quality of plans from both approaches was comparable. From these preliminary results, vector-model-supported optimization can expedite the optimization of VMA-SRT for brain metastasis while maintaining plan quality.

Vector-model-supported approach in prostate plan optimization

Lengthy time consumed in traditional manual plan optimization can limit the use of step-and-shoot intensity-modulated radiotherapy/volumetric-modulated radiotherapy (S&S IMRT/VMAT). A vector model base, retrieving similar radiotherapy cases, was developed with respect to the structural and physiologic features extracted from the Digital Imaging and Communications in Medicine (DICOM) files. Planning parameters were retrieved from the selected similar reference case and applied to the test case to bypass the gradual adjustment of planning parameters. Therefore, the planning time spent on the traditional trial-and-error manual optimization approach in the beginning of optimization could be reduced. Each S&S IMRT/VMAT prostate reference database comprised 100 previously treated cases. Prostate cases were replanned with both traditional optimization and vector-model-supported optimization based on the oncologists' clinical dose prescriptions. A total of 360 plans, which consisted of 30 cases of S&S IMRT, 30 cases of 1-arc VMAT, and 30 cases of 2-arc VMAT plans including first optimization and final optimization with/without vector-model-supported optimization, were compared using the 2-sided t-test and paired Wilcoxon signed rank test, with a significance level of 0.05 and a false discovery rate of less than 0.05. For S&S IMRT, 1-arc VMAT, and 2-arc VMAT prostate plans, there was a significant reduction in the planning time and iteration with vector-model-supported optimization by almost 50%. When the first optimization plans were compared, 2-arc VMAT prostate plans had better plan quality than 1-arc VMAT plans. The volume receiving 35 Gy in the femoral head for 2-arc VMAT plans was reduced with the vector-model-supported optimization compared with the traditional manual optimization approach. Otherwise, the quality of plans from both approaches was comparable. Vector-model-supported optimization was shown to offer much shortened planning time and iteration number without compromising the plan quality.

Concurrent chemoradiation with cisplatin and vinorelbine followed by consolidation with oral vinorelbine in locally advanced non-small cell lung cancer (NSCLC): the phase II CONCAVE study

AIM

Despite recent advances, outcomes for patients with stage III non-small cell lung cancer (NSCLC) with concurrent chemoradiotherapy (CRT) remain poor. We evaluated the combination of ciplatin/vinorelbine and concurrent thoracic radiotherapy followed by consolidation oral vinorelbine in this phase II study.

METHODS

Eligible patients with unresectable stage III NSCLC received cisplatin intravenous (IV) 40 mg/m² and vinorelbine IV 20 mg/m² on days 1, 8, 22 and 29 concurrent with thoracic radiotherapy of 60 Gy in 30 fractions. Four to eight weeks later, oral vinorelbine 60 mg/m² day 1 and 8 every 3 weeks was given for 3 cycles. The primary end point was overall response rate (ORR). Secondary end points were safety, quality of life, progression-free survival (PFS) and overall survival (OS).

RESULTS

Twenty-seven eligible patients were enrolled from December 2007 to June 2010 before the trial was prematurely closed due to toxicity concerns. The median age was 63 years (range, 42-71), 56% were male, 52% ECOG 0 and 52% stage IIIa. The ORR was 81% (including 37% complete response rate) and disease control rate of 93%. The median PFS was 11 months and median OS was 26 months. Consolidation vinorelbine was associated with significant grade 3/4 toxicity (68%) including grade 3-5 febrile neutropenia (27%) and respiratory infections (36%) including two deaths in the consolidation phase (9%).

CONCLUSIONS

Consolidation oral vinorelbine after CRT was associated with significant toxicity. Overall, this regimen achieved a high ORR and survival results comparable to other CRT protocols but the significant toxicity precludes further evaluation of this approach.

Advances in radiotherapy technology for non-small cell lung cancer: What every general practitioner should know

BACKGROUND

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death in Australia. Radiotherapy plays an important role in the curative and palliative settings.

OBJECTIVE

This article reviews recent technological advances that have expanded the radiotherapy treatment options available, and presents standard and emerging approaches to NSCLC.

DISCUSSION

General practitioners play an integral role in the care and education of patients during diagnosis, treatment and
follow-up of NSCLC. Stereotactic (ablative) body radiotherapy,
intensity-modulated radiotherapy, intracranial radiosurgery and hippocampal-avoidance whole-brain radiotherapy are discussed in this article.

Patient preferences regarding prophylactic cranial irradiation: A discrete choice experiment

INTRODUCTION

In patients with non-small cell lung cancer (NSCLC) treated with chemoradiotherapy (CRT), prophylactic cranial irradiation (PCI) is not standard practice. This study determined patient preferences for PCI with respect to survival benefit, reduction in brain metastases (BM) and acceptable toxicity.

METHODS

A Discrete Choice Experiment was completed pre- and post-treatment. Patients made 15 hypothetical choices between two alternative PCI treatments described by four attributes: amount of life gained, chance of BM, ability to care for oneself, and loss of memory. Participants also chose between PCI and no PCI.

RESULTS

54 and 46 surveys were completed pre- and post-treatment. The most important attributes pre-treatment were: a survival benefit >6months, of 3-6months, avoiding severe problems with memory and self-care, avoiding quite a bit of difficulty with memory and maximally reducing BM recurrence. Post-treatment, BM reduction became more important. 90% of patients would accept PCI for a survival benefit >6months, with a maximal reduction in BM even if severe memory/self-care problems occurred. With a 10% reduction in BM and mild problems with memory and self-care 70% of patients pre- (90% post-treatment) would accept PCI for a survival benefit of 1-3months, and 52% pre- (78% post-treatment) for no survival benefit.

CONCLUSION

Improvement in survival is the most important attribute of PCI with patients willing to accept significant toxicity for maximum survival and less toxicity for less survival benefit. BM reduction became more important after treatment. The majority of patients would accept PCI for no survival benefit and a reduction in BM.

Prophylactic cranial irradiation in small cell lung cancer: A single institution experience

AIM

To compare patient demographics, prophylactic cranial irradiation (PCI) utilization and overall survival (OS) of patients with small cell lung cancer (SCLC) referred to a large tertiary center with those reported in large clinical trials.

PATIENTS AND METHODS

A retrospective review was conducted of consecutive patients with limited stage (LS) and extensive stage (ES) SCLC diagnosed at the Princess Alexandra Hospital between January 2008 and December 2013.

RESULTS

Two hundred and three patients with a mean age of 65.4 (±10.7) years were followed for a median duration of 7.6 months (range 0.5-76.5). At diagnosis, 129 (64%) patients had ES-SCLC, including 39 (19.2%) with cerebral metastases. Median OS in LS-SCLC patients receiving PCI was 18.8 months (0.9-69.4), compared with 8.2 months (0.1-34.4) in patients who did not receive PCI (P < 0.001). Median OS in the ES-SCLC cohort receiving PCI was 13.6 months (5.2-37.5) compared to 5.6 months (0.1-73.6) in patients who did not receive the therapy (P < 0.001). There was a significant improvement in intracranial disease-free survival of 7.1 months in patients with ES-SCLC who received PCI. Forty-two LS-SCLC patients (57%) did not receive PCI due to patient suitability.

CONCLUSIONS

In our SCLC cohort, median OS following PCI in LS-SCLC and ES-SCLC is comparable to published data. PCI use at our institution was lower than utilization rates in large meta-analyses, predominately due to poor chemotherapy tolerance and patient suitability. This may be more representative of patients treated in clinical practice rather than those recruited into large phase III trials.

Partial breast irradiation for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). RT is given to sterilize tumour cells that may remain after surgery to decrease the risk of local tumour recurrence. Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypo-fractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialized Register (4 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 5), MEDLINE (January 1966 to 4 May 2015), EMBASE (1980 to 4 May 2015), CINAHL (4 May 2015) and Current Contents (4 May 2015). We searched the International Standard Randomised Controlled Trial Number Register (5 May 2015), the World Health Organization's International Clinical Trials Registry Platform (4 May 2015) and ClinicalTrials.gov (17 June 2015). We searched for grey literature: OpenGrey (17 June 2015), reference lists of articles, several conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomized controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction and used Cochrane's 'Risk of bias' tool, and resolved any disagreements through discussion. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included seven RCTs and studied 7586 women of the 8955 enrolled.Local recurrence-free survival appeared worse for women receiving PBI/APBI compared to WBRT (hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.11 to 2.35; six studies, 6820 participants, low-quality evidence). Cosmesis (physician-reported) appeared worse with PBI/APBI (odds ratio (OR) 1.51, 95% CI 1.17 to 1.95, five studies, 1720 participants, low-quality evidence). Overall survival did not differ with PBI/APBI (HR 0.90, 95% CI 0.74 to 1.09, five studies, 6718 participants, high-quality evidence).Late radiation toxicity (subcutaneous fibrosis) appeared worse with PBI/APBI (OR 6.58, 95% CI 3.08 to 14.06, one study, 766 participants, moderate-quality evidence). Acute skin toxicity appeared reduced with PBI/APBI (OR 0.04, 95% CI 0.02 to 0.09, two studies, 608 participants). Telangiectasia (OR 26.56, 95% CI 3.59 to 196.51, 1 study, 766 participants) and radiological fat necrosis (OR 1.58, 95% CI 1.02 to 2.43, three studies, 1319 participants) appeared worse with PBI/APBI. Late skin toxicity (OR 0.21, 95% CI 0.01 to 4.39, two studies, 608 participants) and breast pain (OR 2.17, 95% CI 0.56 to 8.44, one study, 766 participants) appeared not to differ with PBI/APBI.'Elsewhere primaries' (new primaries in the ipsilateral breast) appeared more frequent with PBI/APBI (OR 3.97, 95% CI 1.51 to 10.41, three studies, 3009 participants).We found no clear evidence of a difference for the comparison of PBI/APBI with WBRT for the outcomes of: cause-specific survival (HR 1.08, 95% CI 0.73 to 1.58, five studies, 6718 participants, moderate-quality evidence), distant metastasis-free survival (HR 0.94, 95% CI 0.65 to 1.37, four studies, 3267 participants, moderate-quality evidence), relapse-free survival (HR 1.36, 95% CI 0.88 to 2.09, three studies, 3811 participants), loco-regional recurrence-free survival (HR 1.80, 95% CI 1.00 to 3.25, two studies, 3553 participants) or mastectomy rates (OR 1.20, 95% CI 0.77 to 1.87, three studies, 4817 participants, low-quality evidence). Compliance was met: more than 90% of the women in all studies received the RT they were assigned to receive. We found no data for the outcomes of costs, quality of life or consumer preference.

AUTHORS' CONCLUSIONS

It appeared that local recurrence and 'elsewhere primaries' (new primaries in the ipsilateral breast) are increased with PBI/APBI (the difference was small), but we found no evidence of detriment to other oncological outcomes. It appeared that cosmetic outcomes and some late effects were worse with PBI/APBI but its use was associated with less acute skin toxicity. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver of PBI/APBI. We await completion of ongoing trials.

Fraction size in radiation therapy for breast conservation in early breast cancer

BACKGROUND

Shortening the duration of radiation therapy would benefit women with early breast cancer treated with breast conserving surgery. It may also improve access to radiation therapy by improving efficiency in radiation oncology departments globally. This can only happen if the shorter treatment is as effective and safe as conventional radiation therapy. This is an update of a Cochrane Review first published in 2008 and updated in 2009.

OBJECTIVES

To assess the effect of altered radiation fraction size for women with early breast cancer who have had breast conserving surgery.

SEARCH METHODS

We searched the Cochrane Breast Cancer Specialised Register (23 May 2015), CENTRAL (The Cochrane Library 2015, Issue 4), MEDLINE (Jan 1996 to May 2015), EMBASE (Jan 1980 to May 2015), the WHO International Clinical Trials Registry Platform (ICTRP) search portal (June 2010 to May 2015) and ClinicalTrials.gov (16 April 2015), reference lists of articles and relevant conference proceedings. No language or publication constraints were applied.

SELECTION CRITERIA

Randomised controlled trials of altered fraction size versus conventional fractionation for radiation therapy in women with early breast cancer who had undergone breast conserving surgery.

DATA COLLECTION AND ANALYSIS

Two authors performed data extraction independently, with disagreements resolved by discussion. We sought missing data from trial authors.

MAIN RESULTS

We studied 8228 women in nine studies. Eight out of nine studies were at low or unclear risk of bias. Altered fraction size (delivering radiation therapy in larger amounts each day but over fewer days than with conventional fractionation) did not have a clinically meaningful effect on: local recurrence-free survival (Hazard Ratio (HR) 0.94, 95% CI 0.77 to 1.15, 7095 women, four studies, high-quality evidence), cosmetic outcome (Risk ratio (RR) 0.90, 95% CI 0.81 to 1.01, 2103 women, four studies, high-quality evidence) or overall survival (HR 0.91, 95% CI 0.80 to 1.03, 5685 women, three studies, high-quality evidence). Acute radiation skin toxicity (RR 0.32, 95% CI 0.22 to 0.45, 357 women, two studies) was reduced with altered fraction size. Late radiation subcutaneous toxicity did not differ with altered fraction size (RR 0.93, 95% CI 0.83 to 1.05, 5130 women, four studies, high-quality evidence). Breast cancer-specific survival (HR 0.91, 95% CI 0.78 to 1.06, 5685 women, three studies, high quality evidence) and relapse-free survival (HR 0.93, 95% CI 0.82 to 1.05, 5685 women, three studies, moderate-quality evidence) did not differ with altered fraction size. We found no data for mastectomy rate. Altered fraction size was associated with less patient-reported (P < 0.001) and physician-reported (P = 0.009) fatigue at six months (287 women, one study). We found no difference in the issue of altered fractionation for patient-reported outcomes of: physical well-being (P = 0.46), functional well-being (P = 0.38), emotional well-being (P = 0.58), social well-being (P = 0.32), breast cancer concerns (P = 0.94; 287 women, one study). We found no data with respect to costs.

AUTHORS' CONCLUSIONS

We found that using altered fraction size regimens (greater than 2 Gy per fraction) does not have a clinically meaningful effect on local recurrence, is associated with decreased acute toxicity and does not seem to affect breast appearance, late toxicity or patient-reported quality-of-life measures for selected women treated with breast conserving therapy. These are mostly women with node negative tumours smaller than 3 cm and negative pathological margins.

The effect of beam arrangements and the impact of non-coplanar beams on the treatment planning of stereotactic ablative radiation therapy for early stage lung cancer

INTRODUCTION

The aim of this study was to compare various coplanar and non-coplanar 3-dimensional conformal radiation therapy (3DCRT) beam arrangements for the delivery of stereotactic ablative radiation therapy (SABR) to patients with early stage lung cancer, based on the dosimetric criteria from the Radiation Therapy Oncology Group (RTOG) 1021 protocol.

METHODS

Ten medically inoperable lung cancer patients eligible for SABR were re-planned using three different coplanar and three different non-coplanar beam arrangements. The plans were compared by assessing planning target volume (PTV) coverage, doses to normal tissues, the high-dose conformity (conformity index) and intermediate dose spillage as defined by the D2cm, (the dose at any point 2 cm away from the PTV), and the R50% (the ratio of the volume of half the prescription dose to the volume of the PTV).

RESULTS

Sixty plans in total were assessed. Mean PTV coverage with the prescription isodose was similar between coplanar (95.14%) and non-coplanar (95.26%) techniques (P = 0.47). There was significant difference between all coplanar and all non-coplanar fields for the R50% (P < 0.0001) but none for the D2cm (P = 0.19). The seven and nine field beam arrangements with two non-coplanar fields had less unacceptable protocol deviations (10 and 7) than the seven and nine field plans with only coplanar fields (13 and 8). The 13 field coplanar fields did not improve protocol compliance with eight unacceptable deviations. The 10 field non-coplanar beam arrangement achieved best compliance with the RTOG 1021 dose criteria with only one unacceptable deviation (maximum rib dose).

CONCLUSION

A 3DCRT planning technique using 10 fields with ≥6 non-coplanar beams best satisfied high and intermediate dose constraints stipulated in the RTOG 1021 trial. Further investigations are required to determine if minor protocol deviations should be balanced against efficiency with the extended treatment times required to deliver non-coplanar fields and if treatment times can be improved using novel intensity modulated techniques.

A comparison of three different VMAT techniques for the delivery of lung stereotactic ablative radiation therapy

INTRODUCTION

The purpose of this study was to investigate coplanar and non-coplanar volumetric modulated arc therapy (VMAT) delivery techniques for stereotactic ablative radiation therapy (SABR) to the lung.

METHODS

For ten patients who had already completed a course of radiation therapy for early stage lung cancer, three new SABR treatment plans were created using (1) a coplanar full arc (FA) technique, (2) a coplanar partial arc technique (PA) and (3) a non-coplanar technique utilising three partial arcs (NCA). These plans were evaluated using planning target volume (PTV) coverage, dose to organs at risk, and high and intermediate dose constraints as incorporated by radiation therapy oncology group (RTOG) 1021.

RESULTS

When the FA and PA techniques were compared to the NCA technique, on average the PTV coverage (V 54Gy) was similar (P = 0.15); FA (95.1%), PA (95.11%) and NCA (95.71%). The NCA resulted in a better conformity index (CI) of the prescription dose (0.89) when compared to the FA technique (0.88, P = 0.23) and the PA technique (0.83, P = 0.06). The NCA technique improved the intermediate dose constraints with a statistically significant difference for the D 2cm and R 50% when compared with the FA (P < 0.03 and <0.0001) and PA (P < 0.04 and <0.0001) techniques. The NCA technique reduced the maximum spinal cord dose by 2.72 and 4.2 Gy when compared to the PA and FA techniques respectively. Mean lung doses were 4.09, 4.31 and 3.98 Gy for the FA, PA and NCA techniques respectively.

CONCLUSION

The NCA VMAT technique provided the highest compliance to RTOG 1021 when compared to coplanar techniques for lung SABR. However, single FA coplanar VMAT was suitable for 70% of patients when minor deviations to both the intermediate dose and organ at risk (OAR) constraints were accepted.

Advances in radiotherapy technology for prostate cancer: What every GP should know

BACKGROUND

One in five Australian men are diagnosed with prostate cancer. External beam radiation therapy (EBRT) is an effective treatment for men suitable for definitive therapy.

OBJECTIVE

This article outlines the processes involved in EBRT for prostate cancer, with particular emphasis on recent technological advances that have had a positive impact on patient outcomes. The patient's experience is explained and comparisons are made with surgery.

DISCUSSION

Patients diagnosed with localised prostate cancer may have multiple treatment options. General practitioners have an important role in helping patients navigate their way through the information needed to make this decision. Radiotherapy technologies, including image guidance, intensity-modulated radiation therapy and stereotactic (ablative) radiation therapy are discussed in this article.

Evaluating the accuracy of the XVI dual registration tool compared with manual soft tissue matching to localise tumour volumes for post-prostatectomy patients receiving radiotherapy

INTRODUCTION

Cone beam computerised tomography (CBCT) enables soft tissue visualisation to optimise matching in the post-prostatectomy setting, but is associated with inter-observer variability. This study assessed the accuracy and consistency of automated soft tissue localisation using XVI's dual registration tool (DRT).

METHODS

Sixty CBCT images from ten post-prostatectomy patients were matched using: (i) the DRT and (ii) manual soft tissue registration by six radiation therapists (RTs). Shifts in the three Cartesian planes were recorded. The accuracy of the match was determined by comparing shifts to matches performed by two genitourinary radiation oncologists (ROs). A Bland-Altman method was used to assess the 95% levels of agreement (LoA). A clinical threshold of 3 mm was used to define equivalence between methods of matching.

RESULTS

The 95% LoA between DRT-ROs in the superior/inferior, left/right and anterior/posterior directions were -2.21 to +3.18 mm, -0.77 to +0.84 mm, and -1.52 to +4.12 mm, respectively. The 95% LoA between RTs-ROs in the superior/inferior, left/right and anterior/posterior directions were -1.89 to +1.86 mm, -0.71 to +0.62 mm and -2.8 to +3.43 mm, respectively. Five DRT CBCT matches (8.33%) were outside the 3-mm threshold, all in the setting of bladder underfilling or rectal gas. The mean time for manual matching was 82 versus 65 s for DRT.

CONCLUSIONS

XVI's DRT is comparable with RTs manually matching soft tissue on CBCT. The DRT can minimise RT inter-observer variability; however, involuntary bladder and rectal filling can influence the tools accuracy, highlighting the need for RT evaluation of the DRT match.

Outcomes treating stage III non-small cell lung carcinoma with curative-intent radiotherapy and concurrent carboplatin-paclitaxel chemotherapy

BACKGROUND AND AIM

Thoracic radiotherapy administered concurrently with chemotherapy is the standard of care for patients with inoperable stage III non-small cell lung cancer, but the optimal chemotherapy regimen is not clearly established. The objective of this study was to assess outcomes in a large cohort of patients treated with curative-intent using carboplatin and paclitaxel.

METHODS

Consecutive patients undergoing curative-intent radiotherapy to 60-66 Gy in 30-33 daily fractions with concurrent weekly carboplatin (AUC = 2) and paclitaxel (45 mg/m(2) /week) between March 2004 and May 2012 were identified from a prospective database and reviewed individually. A minimum follow-up of 3 months was required unless death occurred sooner. Response to treatment was defined according to established guidelines on re-staging computed tomography scan at 3 months. Toxicities were assessed using a standardised scoring system.

RESULTS

One hundred and seven patients were analysed. The median follow-up was 43.5 months. Three months after treatment, a complete or partial response was observed in 72 patients (68%), and nine patients (8%) had already died. The overall locoregional failure rate was 47%, and failure eventually occurred at any site in 75 patients (70%). Median progression-free survival, and median survival were 15 and 22 months, respectively. Grade 3-4 neutropaenia, thrombocytopaenia, nephrotoxicity, oesophagitis and pneumonitis were observed in 15%, 1%, 3%, 11% and 9% of patients during treatment, respectively. There was one episode of fatal radiation pneumonitis.

CONCLUSION

Treatment with thoracic radiotherapy and concurrent carboplatin and paclitaxel chemotherapy is feasible. Survival and toxicity outcomes compare favorably to those reported using cisplatin-based regimens.

Partial breast irradiation for early breast cancer

BACKGROUND

Breast conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiation therapy (RT). RT is given to sterilize tumour cells that may remain after surgery to decrease the risk of local tumour recurrence. Most true recurrences occur in the same quadrant as the original tumour. Whole breast RT may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the role of delivering radiation to a limited volume of the breast around the tumour bed (partial breast irradiation: PBI) sometimes with a shortened treatment duration (accelerated partial breast irradiation: APBI).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast conservation therapy for early-stage breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialised Register (07 November 2013), CENTRAL (2014, Issue 3), MEDLINE (January 1966 to 11 April 2014), EMBASE (1980 to 11 April 2014), CINAHL (11 April 2014) and Current Contents (11 April 2014). Also we searched the International Standard Randomised Controlled Trial Number Register, the World Health Organization's International Clinical Trials Registry Platform (07 November 2013) and US clinical trials registry (www.clinicaltrials.gov) (22 April 2014). We searched for grey literature: Open Grey (23 April 2014), reference lists of articles, a number of conference proceedings and published abstracts, and did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding and evaluating conservative surgery plus PBI/APBI versus conservative surgery plus whole breast RT. We included both published and unpublished trials.

DATA COLLECTION AND ANALYSIS

Three review authors (ML, DF and BH) performed data extraction and resolved any disagreements through discussion. We entered data into Review Manager for analysis. BH and ML assessed trials, graded the methodological quality using Cochrane's Risk of Bias tool and resolved any disagreements through discussion.

MAIN RESULTS

We included four RCTs that had 2253 women. Two older trials examined RT techniques which do not reflect current practice and one trial had a short follow-up. We downgraded the quality of the evidence for our key outcomes due to risk of bias. Taken together with other GRADE recommendations, the quality of evidence for our outcomes was very low to low. For the comparison of partial breast irradiation/accelerated breast irradiation (PBI/APBI) with whole breast irradiation (WBRT), local recurrence-free survival appeared worse (Hazard Ratio (HR) 1.74, 95% confidence interval (CI) 1.23 to 2.45; three trials, 1140 participants, very low quality evidence). Cosmesis appeared improved with PBI/APBI in a single trial (OR 0.40, 95% CI 0.23 to 0.72; one trial, 241 participants, very low quality evidence), but late toxicity (telangiectasia OR 4.41, 95% CI 3.21 to 6.05; very low quality evidence, 708 participants) and subcutaneous fibrosis (OR 4.27, 95% CI 3.04 to 6.01; one trial, 710 participants, very low quality evidence) appeared increased in another trial. We found no clear evidence of a difference for the comparison of PBI/APBI versus WBRT for the outcomes of: overall survival (HR 0.99, 95% CI 0.83 to 1.18; three trials, 1140 participants, very low quality evidence), cause-specific survival (HR 0.95, 95% CI 0.74 to 1.22; two trials, 966 participants, low evidence quality), distant metastasis-free survival (HR 1.02, 95% CI 0.81 to 1.28; 1140 participants, low quality evidence), subsequent mastectomy rate (OR 0.20, 95% CI 0.01 to 4.21; 258 participants, low quality evidence) and relapse-free survival (HR 0.99, 95% CI 0.53 to 1.85; 258 participants, low quality evidence). We found no data for the outcomes of acute toxicity, new ipsilateral breast primaries, costs, quality of life or consumer preference.

AUTHORS' CONCLUSIONS

The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver of PBI/APBI. We await completion of ongoing trials.

A large-scale, rapid public health response to rabies in an organ recipient and the previously undiagnosed organ donor

This article describes and contrasts the public health response to two human rabies cases: one organ recipient diagnosed within days of symptom onset and the transplant donor who was diagnosed 18 months post-symptom onset. In response to an organ-transplant-related rabies case diagnosed in 2013, organ donor and recipient investigations were conducted by multiple public health agencies. Persons with potential exposure to infectious patient materials were assessed for rabies virus exposure. An exposure investigation was conducted to determine the source of the organ donor's infection. Over 100 persons from more than 20 agencies spent over 2700 h conducting contact investigations in healthcare, military and community settings. The 564 persons assessed include 417 healthcare workers [5.8% recommended for post-exposure prophylaxis (PEP)], 96 community contacts (15.6% recommended for PEP), 30 autopsy personnel (50% recommended for PEP), and 21 other persons (4.8% recommended for PEP). Donor contacts represented 188 assessed with 20.2% recommended for PEP, compared with 5.6% of 306 recipient contacts recommended for PEP. Human rabies cases result in substantial use of public health and medical resources, especially when diagnosis is delayed. Although rare, clinicians should consider rabies in cases of encephalitis of unexplained aetiology, particularly for cases that may result in organ donation.