Utility of 30-Day Mortality Following Systemic Anti-Cancer Treatment as a Quality Indicator in Advanced Lung Cancer.

BACKGROUND: 30-day mortality after systemic anti-cancer therapy (SACT) has been suggested as a quality indicator primarily for measuring use of chemotherapy towards the end of life. Utility across different cancer types is unclear, especially when using immunotherapy and targeted therapies. METHODS: This retrospective study included patients with a diagnosis of lung cancer who received palliative-intent SACT at an Australian metropolitan cancer center between 2015 and 2022. Using a prospectively maintained lung cancer database, patient, disease, and treatment characteristics were evaluated against annual 30-day mortality rates following SACT. RESULTS: 1072 patients were identified. Annual 30-day mortality rate after palliative-intent SACT for lung cancer ranged between 9% and 15%, with significant variance between treatment types. Calculated rates of 30-day mortality are higher if longer reporting time periods are used. Patients who died within 30 days of SACT were more likely to have received targeted therapies or immunotherapy as their final line of treatment, have a poorer performance status at diagnosis, and have received multiple lines of treatment. CONCLUSIONS: Our data support differential interpretation of 30-day mortality for quality assurance, especially with regard to lung cancer. Consistency in population and reporting time periods, and accounting for treatment type is crucial if 30-day mortality is to be utilized as cancer care performance quality indicator. Relevance to quality care is questionable in the lung cancer setting.

The impact of pre-treatment smoking status on survival after chemoradiotherapy for locally advanced non-small-cell lung cancer.

INTRODUCTION: Smoking is a risk factor for the development of lung cancer and reduces life expectancy within the general population. Retrospective studies suggest that non-smokers have better outcomes after treatment for lung cancer. We used a prospective database to investigate relationships between pre-treatment smoking status and survival for a cohort of patients with stage III non-small-cell lung cancer (NSCLC) treated with curative-intent concurrent chemoradiotherapy (CRT). METHODS: All patients treated with CRT for stage III NSCLC at a major metropolitan cancer centre were prospectively registered to a database. A detailed smoking history was routinely obtained at baseline. Kaplan-Meier statistics were used to assess overall survival and progression-free survival in never versus former versus current smokers. RESULTS: Median overall survival for 265 eligible patients was 2.21 years (95 % Confidence Interval 1.78, 2.84). It was 5.5 years (95 % CI 2.1, not reached) for 25 never-smokers versus 1.9 years (95 % CI 1.5, 2.7) for 182 former smokers and 2.2 years (95 % CI 1.3, 2.7) for 58 current smokers. Hazard ratio for death was 2.43 (95 % CI 1.32-4.50) for former smokers and 2.75 (95 % CI 1.40, 5.40) for current smokers, p = 0.006. Actionable tumour mutations (EGFR, ALK, ROS1) were present in more never smokers (14/25) than former (9/182) or current (3/58) smokers. TKI use was also higher in never smokers but this was not significantly associated with superior survival (Hazard ratio 0.71, 95 % CI 0.41, 1.26). CONCLUSIONS: Never smokers have substantially better overall survival than former or current smokers after undergoing CRT for NSCLC.

First-line chemoimmunotherapy and immunotherapy in patients with non-small cell lung cancer and brain metastases: a registry study.

Introduction: Brain metastases commonly occur in patients with non-small cell lung cancer (NSCLC). Standard first-line treatment for NSCLC, without an EGFR, ALK or ROS1 mutation, is either chemoimmunotherapy or anti-PD-1 monotherapy. Traditionally, patients with symptomatic or untreated brain metastases were excluded from the pivotal clinical trials that established first-line treatment recommendations. The intracranial effectiveness of these treatment protocols has only recently been elucidated in small-scale prospective trials. Methods: Patients with NSCLC and brain metastases, treated with first-line chemoimmunotherapy or anti-PD-1 monotherapy were selected from the Australian Registry and biObank of thoracic cancers (AURORA) clinical database covering seven institutions. The primary outcome was a composite time-to-event (TTE) outcome, including extracranial and intracranial progression, death, or need for local intracranial therapy, which served as a surrogate for disease progression. The secondary outcome included overall survival (OS), intracranial objective response rate (iORR) and objective response rate (ORR). Results: 116 patients were included. 63% received combination chemoimmunotherapy and 37% received anti-PD-1 monotherapy. 69% of patients received upfront local therapy either with surgery, radiotherapy or both. The median TTE was 7.1 months (95% CI 5 - 9) with extracranial progression being the most common progression event. Neither type of systemic therapy or upfront local therapy were predictive of TTE in a multivariate analysis. The median OS was 17 months (95% CI 13-27). Treatment with chemoimmunotherapy was predictive of longer OS in multivariate analysis (HR 0.35; 95% CI 0.14 - 0.86; p=0.01). The iORR was 46.6%. The iORR was higher in patients treated with chemoimmunotherapy compared to immunotherapy (58% versus 31%, p=0.01). The use of chemoimmunotherapy being predictive of iORR in a multivariate analysis (OR 2.88; 95% CI 1.68 - 9.98; p=0.04). Conclusion: The results of this study of real-world data demonstrate the promising intracranial efficacy of chemoimmunotherapy in the first-line setting, potentially surpassing that of immunotherapy alone. No demonstrable difference in survival or TTE was seen between receipt of upfront local therapy. Prospective studies are required to assist clinical decision making regarding optimal sequencing of local and systemic therapies.

Patterns of care for people with small cell lung cancer in Victoria, 2011-19: a retrospective, population-based registry data study.

OBJECTIVES: To report stage-specific patterns of treatment and the influence of management and treatment type on survival rates for people newly diagnosed with small cell lung cancer (SCLC). DESIGN: Cross-sectional patterns of care study; analysis of data prospectively collected for the Victorian Lung Cancer Registry (VLCR). SETTING, PARTICIPANTS: All people diagnosed with SCLC in Victoria during 1 April 2011 - 18 December 2019. MAIN OUTCOME MEASURES: Stage-specific management and treatment of people with SCLC; median survival time. RESULTS: During 2011-19, 1006 people were diagnosed with SCLC (10.5% of all lung cancer diagnoses in Victoria); their median age was 69 years (interquartile range [IQR], 62-77 years), 429 were women (43%), and 921 were current or former smokers (92%). Clinical stage was defined for 896 people (89%; TNM stages I-III, 268 [30%]; TNM stage IV, 628 [70%]) and ECOG performance status at diagnosis for 663 (66%; 0 or 1, 489 [49%]; 2-4, 174 [17%]). The cases of 552 patients had been discussed at multidisciplinary meetings (55%), 377 people had received supportive care screening (37%), and 388 had been referred for palliative care (39%). Active treatment was received by 891 people (89%): chemotherapy, 843 (84%); radiotherapy, 460 (46%); chemotherapy and radiotherapy, 419 (42%); surgery, 23 (2%). Treatment had commenced within fourteen days of diagnosis for 632 of 875 patients (72%). Overall median survival time from diagnosis was 8.9 months (IQR, 4.2-16 months; stage I-III: 16.3 [IQR, 9.3-30] months; stage IV: 7.2 [IQR, 3.3-12] months). Multidisciplinary meeting presentation (hazard ratio [HR], 0.66; 95% CI, 0.58-0.77), multimodality treatment (HR, 0.42; 95% CI, 0.36-0.49), and chemotherapy within fourteen days of diagnosis (HR, 0.68; 95% CI, 0.48-0.94) were each associated with lower mortality during follow-up. CONCLUSION: Rates of supportive care screening, multidisciplinary meeting evaluation, and palliative care referral for people with SCLC could be improved. A national registry of SCLC-specific management and outcomes data could improve the quality and safety of care.

Persisting Gaps in Optimal Care of Stage III Non-small Cell Lung Cancer: An Australian Patterns of Care Analysis.

BACKGROUND: Wide variation exists globally in the treatment and outcomes of stage III patients with non-small cell lung cancer (NSCLC). We conducted an up-to-date patterns of care analysis in the state of Victoria, Australia, with a particular focus on the proportion of patients receiving treatment with radical intent, treatment trends over time, and survival. MATERIALS AND METHODS: Stage III patients with NSCLC were identified in the Victorian Lung Cancer Registry and categorized by treatment received and treatment intent. Logistic regression was used to explore factors predictive of receipt of radical treatment and the treatment trends over time. Cox regression was used to explore variables associated with overall survival (OS). Covariates evaluated included age, sex, ECOG performance status, smoking status, year of diagnosis, Australian born, Aboriginal or Torres Strait Islander status, socioeconomic status, rurality, public/private status of notifying institution, and multidisciplinary meeting discussion. RESULTS: A total of 1396 patients were diagnosed between 2012 and 2019 and received treatment with radical intent 67%, palliative intent 23%, unknown intent 5% and no treatment 5%. Radical intent treatment was less likely if patients were >75 years, ECOG ≥1, had T3-4 or N3 disease or resided rurally. Surgery use decreased over time, while concurrent chemoradiotherapy and immunotherapy use increased. Median OS was 38.0, 11.1, and 4.4 months following radical treatment, palliative treatment or no treatment, respectively. CONCLUSION: Almost a third of stage III patients with NSCLC still do not receive radical treatment. Strategies to facilitate radical treatment and better support decision making between increasing multimodality options are required.

Development of an Australia and New Zealand Lung Cancer Clinical Quality Registry: a protocol paper.

INTRODUCTION: Lung cancer is the leading cause of cancer mortality, comprising the largest national cancer disease burden in Australia and New Zealand. Regional reports identify substantial evidence-practice gaps, unwarranted variation from best practice, and variation in processes and outcomes of care between treating centres. The Australia and New Zealand Lung Cancer Registry (ANZLCR) will be developed as a Clinical Quality Registry to monitor the safety, quality and effectiveness of lung cancer care in Australia and New Zealand. METHODS AND ANALYSIS: Patient participants will include all adults >18 years of age with a new diagnosis of non-small-cell lung cancer (NSCLC), SCLC, thymoma or mesothelioma. The ANZLCR will register confirmed diagnoses using opt-out consent. Data will address key patient, disease, management processes and outcomes reported as clinical quality indicators. Electronic data collection facilitated by local data collectors and local, state and federal data linkage will enhance completeness and accuracy. Data will be stored and maintained in a secure web-based data platform overseen by registry management. Central governance with binational representation from consumers, patients and carers, governance, administration, health department, health policy bodies, university research and healthcare workers will provide project oversight. ETHICS AND DISSEMINATION: The ANZLCR has received national ethics approval under the National Mutual Acceptance scheme. Data will be routinely reported to participating sites describing performance against measures of agreed best practice and nationally to stakeholders including federal, state and territory departments of health. Local, regional and (bi)national benchmarks, augmented with online dashboard indicator reporting will enable local targeting of quality improvement efforts.

Practical considerations of single-fraction stereotactic ablative radiotherapy to the lung.

Stereotactic ablative radiotherapy (SABR) is a well-established treatment for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) and pulmonary oligometastases. The use of single-fraction SABR in this setting is supported by excellent local control and safety profiles which appear equivalent to multi-fraction SABR based on the available data. The resource efficiency and reduction in hospital outpatient visits associated with single-fraction SABR have been particularly advantageous during the COVID-19 pandemic. Despite the increased interest, single-fraction SABR in subgroups of patients remains controversial, including those with centrally located tumours, synchronous targets, proximity to dose-limiting organs at risk, and concomitant severe respiratory illness. This review provides an overview of the published randomised evidence evaluating single-fraction SABR in primary lung cancer and pulmonary oligometastases, the common clinical challenges faced, immunogenic effect of SABR, as well as technical and cost-utility considerations.

Quality indicators for radiation oncology.

Quality Indicators, based on clinical practice guidelines, have been used in medicine and within oncology to measure quality of care for over twenty years. However, radiation oncology quality indicators are sparse. This article describes the background to the development of current national and international, general and tumour site-specific radiation oncology quality indicators in use. We explore challenges and opportunities to expand their routine prospective collection and feedback to help drive improvements in the quality of care received by people undergoing radiation therapy.

Biomarker Testing for People With Advanced Lung Cancer in England.

INTRODUCTION: Optimal management of people with advanced NSCLC depends on accurate identification of predictive markers. Yet, real-world data in this setting are limited. We describe the impact, timeliness, and outcomes of molecular testing for patients with advanced NSCLC and good performance status in England. METHODS: In collaboration with Public Health England, patients with stages IIIB to IV NSCLC, with an Eastern Cooperative Oncology Group performance status of 0 to 2, in England, between June 2017 and December 2017, were identified. All English hospitals were invited to record information. RESULTS: A total of 60 of 142 invited hospitals in England participated in this study and submitted data on 1157 patients. During the study period, 83% of patients with advanced adenocarcinoma underwent molecular testing for three recommended predictive biomarkers (EGFR, ALK, and programmed death-ligand 1). A total of 80% of patients with nonsquamous carcinomas on whom biomarker testing was performed had adequate tissue for analysis on initial sampling. First-line treatment with a tyrosine kinase inhibitor was received by 71% of patients with adenocarcinoma and a sensitizing EGFR mutation and by 59% of those with an ALK translocation. Of patients with no driver mutation and a programmed death-ligand 1 expression of greater than or equal to 50%, 47% received immunotherapy. CONCLUSIONS: We present a comprehensive data set for molecular testing in England. Although molecular testing is well established in England, timeliness and uptake of targeted therapies should be improved.

Age-related treatment patterns for stage I NSCLC in three European countries.

INTRODUCTION: Surgery is the preferred treatment for patients with early-stage non-small cell lung cancer (NSCLC) while stereotactic body radiation therapy (SBRT) may be applied in patients with major comorbidity or high age. We evaluated the association between age and treatment utilization for early-stage NSCLC in patients diagnosed in 2015-2016 in three European countries. PATIENTS AND METHODS: Information was retrieved from population-based registries in England, Norway and the Netherlands. Treatment patterns and two-year overall survival rates for 105,124 patients with clinical stage I were analysed by age-group. RESULTS: Surgical resection rates were higher in Norway (55%) and England (53%) than in the Netherlands (47%), and decreased with increasing age. SBRT use was highest in the Netherlands (41%), followed by Norway (29%) and England (12%). In the Netherlands, SBRT was the prevailing treatment in patients aged 70 years or older. In octogenarians, the proportion not receiving curative intent treatment was 53% in England, versus 35% in Norway and 22% in the Netherlands. Two-year survival rates were better for surgery than for SBRT and slightly better in Norway. CONCLUSION: In patients aged 70 years or older, the proportion not receiving any curative treatment remains substantial, and differs significantly between countries. Measures to address these disparities are needed.

Treatment Allocation and Survival in Patients Diagnosed with Nonmetastatic Muscle-invasive Bladder Cancer: An Analysis of a National Patient Cohort in England.

BACKGROUND: UK Bladder cancer survival remains low. Nonmetastatic muscle-invasive bladder cancer (MIBC) is potentially curable. It is unclear how many patients receive nonradical treatment owing to advanced age, comorbidities, or alternative factors. OBJECTIVE: To describe treatments and assess survival by disease stage and sex for all newly diagnosed nonmetastatic MIBC in England in 2016, and to observe associations between comorbidities and treatments. DESIGN, SETTING, AND PARTICIPANTS: All new nonmetastatic MIBC diagnoses in England in 2016 were identified retrospectively using National Cancer Registration and Analysis Service, Radiotherapy Datasets, Systemic Anti-Cancer Therapy, and Hospital Episode Statistics databases. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Age, Charlson Comorbidity Index (CCI), and treatments were ascertained, and 1-yr survival was estimated using Pohar-Perme and Kaplan-Meier methods. RESULTS AND LIMITATIONS: Nonmetastatic MIBC diagnoses were registered for 2519 patients (median age 76 yr). Radical cystectomy was performed in 24%, 37% of whom received neoadjuvant chemotherapy (NAC). Radical radiotherapy was performed in 29%, 48% of whom received NAC. NAC alongside radical treatment was associated with higher 1-yr overall survival (OS)-91% (88-93%) with NAC and 83% (80-85%) without (p = 0.05). Nonradical treatments occurred for 47%, with corresponding lower OS. Females with stage II and III disease had significantly lower net survival (NS). Radically treated patients had lower CCIs. CONCLUSIONS: This analysis provides an overview of all nonmetastatic MIBC diagnosed in England in 2016. Just over half of the patients received curative-intent treatment. Of them, only 43% received NAC. One-year OS was disparate, correlating with treatment intensity. Those receiving NAC and radical therapy demonstrated highest OS. Female patients had significantly inferior NS. The data highlight a prescient unmet research need to understand the patient demographic and reasons behind treatment allocation, to address the poor survival observed in those treated nonradically, and the low NAC utilisation. The significantly aged population requires specific future focus. PATIENT SUMMARY: We looked at all patients in England in 2016 who were diagnosed with bladder cancer invading the bladder muscle. Many patients were elderly, and the most intensive treatments aiming for cure were frequently not used. Survival in women was found to be considerably worse, as was survival for less intensively treated patients.

Isotoxic Intensity Modulated Radiation Therapy in Stage III Non-Small Cell Lung Cancer: A Feasibility Study.

PURPOSE: Not all patients with stage III non-small cell lung cancer (NSCLC) are suitable for concurrent chemoradiation therapy (CRT). Local failure rate is high for sequential concurrent CRT. As such, there is a rationale for treatment intensification. METHODS AND MATERIALS: Isotoxic intensity modulated radiation therapy (IMRT) is a multicenter feasibility study that combines different intensification strategies including hyperfractionation, acceleration, and dose escalation facilitated by IMRT. Patients with unresectable stage III NSCLC, Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2, and unsuitable for concurrent CRT were recruited. A minimum of 2 cycles of platinum-based chemotherapy was compulsory before starting radiation therapy (RT). Radiation dose was increased until a maximum dose of 79.2 Gy was reached or 1 or more of the organs at risk met predefined constraints. RT was delivered in 1.8-Gy fractions twice daily, and an RT quality assurance program was implemented. The primary objective was the delivery of isotoxic IMRT to a dose >60 Gy equivalent dose in 2-Gy fractions (EQD2 assuming an α/ß ratio of 10 Gy for acute reacting tissues). RESULTS: Thirty-seven patients were recruited from 7 UK centers. Median age was 69.9 years (range, 46-86 years). The male-to-female ratio was 17:18. ECOG PS was 0 to 5 in 14.2% of patients; PS was 1 to 27 in 77.1% of patients; PS was 2 to 3 in 8.6% of patients. Stage IIIA:IIIB ratio was 22:13 (62.9%:37.1%). Of 37 patients, 2 (5.4%) failed to achieve EQD2 > 60 Gy. Median prescribed tumor dose was 77.4 Gy (range, 61.2-79.2 Gy). A maximum dose of 79.2Gy was achieved in 14 patients (37.8%). Grade 3 esophagitis was reported in 2 patients, and no patients developed grade 3 to 4 pneumonitis. There were 3 grade 5 events: acute radiation pneumonitis, bronchopulmonary hemorrhage, and acute lung infection. Median follow-up at time of analysis was 25.4 months (range, 8.0-44.2) months for 11 of 35 survivors. The median survival was 18.1 months (95% confidence interval [CI], 13.9-30.6), 2-year overall survival was 33.6% (95% CI, 17.9-50.1), and progression-free survival was 23.9% (95% CI, 11.3-39.1). CONCLUSIONS: Isotoxic IMRT is a well-tolerated and feasible approach to treatment intensification.

Standards of care in mesothelioma treatment.

The UK has the highest incidence of mesothelioma in the world, but services vary across the country partly due to uneven geographical distribution of cases. The Mesothelioma UK-funded national organisational audit has highlighted challenges in accessing diagnostic procedures such as thoracoscopy, as well as identifying examples of best practice, including access to clinical trials and specialist therapeutic procedures. To ensure equitable and optimal patient care, cancer alliances should have established referral pathways to specialist multidisciplinary team (MDT) services for discussion of all mesothelioma patients.

Long-Term Results from the IDEAL-CRT Phase 1/2 Trial of Isotoxically Dose-Escalated Radiation Therapy and Concurrent Chemotherapy for Stage II/III Non-small Cell Lung Cancer.

PURPOSE: The IDEAL-CRT phase 1/2 multicenter trial of isotoxically dose-escalated concurrent chemoradiation for stage II/III non-small cell lung cancer investigated two 30-fraction schedules of 5 and 6 weeks' duration. We report toxicity, tumor response, progression-free survival (PFS), and overall survival (OS) for both schedules, with long-term follow-up for the 6-week schedule. METHODS AND MATERIALS: Patients received isotoxically individualized tumor radiation doses of 63 to 71 Gy in 5 weeks or 63 to 73 Gy in 6 weeks, delivered concurrently with 2 cycles of cisplatin and vinorelbine. Eligibility criteria were the same for both schedules. RESULTS: One-hundred twenty patients (6% stage IIB, 68% IIIA, 26% IIIB, 1% IV) were recruited from 9 UK centers, 118 starting treatment. Median prescribed doses were 64.5 and 67.6 Gy for the 36 and 82 patients treated using the 5- and 6-week schedules. Grade ≥3 pneumonitis and early esophagitis rates were 3.4% and 5.9% overall and similar for each schedule individually. Late grade 2 esophageal toxicity occurred in 11.1% and 17.1% of 5- and 6-week patients. Grade ≥4 adverse events occurred in 17 (20.7%) 6-week patients but no 5-week patients. Four adverse events were grade 5, with 2 considered radiation therapy related. After median follow-up of 51.8 and 26.4 months for the 6- and 5-week schedules, median OS was 41.2 and 22.1 months, respectively, and median PFS was 21.1 and 8.0 months. In exploratory analyses, OS was significantly associated with schedule (hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.32-0.98; P = .04) and fractional clinical/internal target volume receiving ≥95% of the prescribed dose (HR, 0.88; 95% CI, 0.77-1.00; P = .05). PFS was also significantly associated with schedule (HR, 0.53; 95% CI, 0.33-0.86; P = .01). CONCLUSIONS: Toxicity in IDEAL-CRT was acceptable. Survival was promising for 6-week patients and significantly longer than for 5-week patients. Survival might be further lengthened by following the 6-week schedule with an immune agent, motivating further study of such combined optimized treatments.

Post-treatment survival difference between lobectomy and stereotactic ablative radiotherapy in stage I non-small cell lung cancer in England.

BACKGROUND: Approximately 15%-20% of all non-small cell lung cancer (NSCLC) cases present with stage I disease. Surgical resection traditionally offers the best chance of a cure but some patients will not have this treatment due to older age, comorbidities or personal choice. Stereotactic ablative radiotherapy (SABR) has become an established curative intent treatment option for patients who are not selected for or do not choose surgery. The aim of this study is to compare survival at 90 days, 6 months, 1 year and 2 years for patients who received either lobectomy or SABR. METHODS: We used data from the 2015 National Lung Cancer Audit database and linked with Hospital Episode Statistics and the radiotherapy dataset to identify patients with NSCLC stage IA-IB and performance status (PS) 0-2 who underwent surgery or SABR treatment. We assessed the likelihood of death at 90 days, 6 months, 1 year and 2 year after diagnosis and procedure date to observe survival between two patient groups. RESULTS: We identified 2373 patients in our cohort, 476 of whom had SABR. The median difference between date of diagnosis and date of treatment for surgery patients was 17 days while for SABR patients it was 73 days. Increasing age and worsening PS were associated with having SABR rather than surgery. Survival between the two treatment modalities was similar early on but by 1-year people who had surgery did better than those who had SABR (adjusted ORs 2.12, 95% CI 1.35 to 2.31). This difference persisted at 2 years and when the analysis was restricted to patients aged <80 years and with PS 0 or 1 and stage IA only. CONCLUSION: Our analysis suggests that patients who have lobectomy have a better survival compared with SABR patients; however, we found considerable delays in patients receiving SABR which may contribute to poorer long-term outcomes with this treatment option. Reducing these delays should be a key focus in development and reorganisation of services.

An evaluation of the mid-ventilation method for the planning of stereotactic lung plans.

BACKGROUND AND PURPOSE: Stereotactic ablative body radiotherapy for lung plans requires 4DCT. Most radiotherapy centres use this to determine an internal target volume (ITV), despite studies suggesting that planning on a mid-ventilation (Mid-V) phase can reduce target volumes. The purpose of this study is two-fold: to determine whether the Mid-V approach provides adequate coverage and to discuss methods to enable the Mid-V approach to be applied more widely. METHOD: 4D scans of 79 patients were outlined on every phase. The mid-V phase was identified. Margins were determined from the range of motion, and plans generated with a 55 Gy prescription. A grid-based method was used to get the probability of tumour coverage in the presence of systematic and random uncertainties, with and without blurring for breathing motion. RESULTS: For the Mid-V plans with the margins calculated from the van-Herk formula, after blurring doses for breathing, the coverage (dose covering 95% of the CTV 95% of the time) was greater than for plans with isotropic 5 mm margins uncorrected for breathing (58.2 Gy v 57.3 Gy). Similar results were obtained for a linear margin chosen as 0.15 of the breathing range. Deformable contour propagation in a commercial outlining system (ProSoma) identified the same mid-V phase in the majority of cases. CONCLUSION: Our results confirm that a mid-V approach can be used to reduce the PTV size, with no loss of tumour coverage. We propose the use of a simplified margin formula equal to the margin ignoring breathing plus 0.15 of the range of motion.