Clinicoradiological outcomes after radical radiotherapy for lung cancer in patients with interstitial lung disease.

Objective: Interstitial lung disease (ILD) is relatively common in patients with lung cancer with an incidence of 7.5%. Historically pre-existing ILD was a contraindication to radical radiotherapy owing to increased radiation pneumonitis rates, worsened fibrosis and poorer survival compared with non-ILD cohorts. Herein, the clinical and radiological toxicity outcomes of a contemporaneous cohort are described. Methods: Patients with ILD treated with radical radiotherapy for lung cancer at a regional cancer centre were collected prospectively. Radiotherapy planning, tumour characteristics, and pre- and post-treatment functional and radiological parameters were recorded. Cross-sectional images were independently assessed by two Consultant Thoracic Radiologists. Results: Twenty-seven patients with co-existing ILD received radical radiotherapy from February 2009 to April 2019, with predominance of usual interstitial pneumonia subtype (52%). According to ILD-GAP scores, most patients were Stage I. After radiotherapy, localised (41%) or extensive (41%) progressive interstitial changes were noted for most patients yet dyspnoea scores (n = 15 available) and spirometry (n = 10 available) were stable. One-third of patients with ILD went on to receive long-term oxygen therapy, which was significantly more than the non-ILD cohort. Median survival trended towards being worse compared with non-ILD cases (17.8 vs 24.0 months, p = 0.834). Conclusion: Radiological progression of ILD and reduced survival were observed post-radiotherapy in this small cohort receiving lung cancer radiotherapy, although a matched functional decline was frequently absent. Although there is an excess of early deaths, long-term disease control is achievable. Advances in knowledge: For selected patients with ILD, long-term lung cancer control without severely impacting respiratory function may be possible with radical radiotherapy, albeit with a slightly higher risk of death.

A pulmonary vein atlas for radiotherapy planning.

BACKGROUND AND PURPOSE: Cardiac arrhythmia is a recognised potential complication of thoracic radiotherapy, but the responsible cardiac substructures for arrhythmogenesis have not been identified. Arrhythmogenic tissue is commonly located in the pulmonary veins (PVs) of cardiology patients with arrhythmia, however these structures are not currently considered organs-at-risk during radiotherapy planning. A standardised approach to their delineation was developed and evaluated. MATERIALS AND METHODS: The gross and radiological anatomy relevant to atrial fibrillation was derived from cardiology and radiology literature by a multidisciplinary team. A region of interest and contouring instructions for radiotherapy computed tomography scans were iteratively developed and subsequently evaluated. Radiation oncologists (n = 5) and radiation technologists (n = 2) contoured the PVs on the four-dimensional planning datasets of five patients with locally advanced lung cancer treated with 1.8-2.75 Gy fractions. Contours were compared to reference contours agreed by the researchers using geometric and dosimetric parameters. RESULTS: The mean dose to the PVs was 35% prescription dose. Geometric and dosimetric similarity of the observer contours with reference contours was fair, with an overall mean Dice of 0.80 ± 0.02. The right superior PV (mean DSC 0.83 ± 0.02) had better overlap than the left (mean DSC 0.80 ± 0.03), but the inferior PVs were equivalent (mean DSC of 0.78). The mean difference in mean dose was 0.79 Gy ± 0.71 (1.46% ± 1.25). CONCLUSION: A PV atlas with multidisciplinary approval led to reproducible delineation for radiotherapy planning, supporting the utility of the atlas in future clinical radiotherapy cardiotoxicity research encompassing arrhythmia endpoints.

Coincidental splenic irradiation and risk of functional hyposplenism in oesophageal cancer treatment.

INTRODUCTION: Definitive chemoradiotherapy (dCRT) and radical radiotherapy are central to the management of distal oesophageal carcinoma. This study sought to establish whether the spleen receives a significant incidental radiation dose when treating distal oesophageal carcinoma with the standardised dCRT or radical radiotherapy doses. METHODS: In this single-centre retrospective study, all patients (n = 34) with distal oesophageal cancer, treated with either dCRT or radical radiotherapy over an 18-month period using a volumetric modulated arc therapy (VMAT) planning technique, were included. The median age was 74 years old: 56% were male; 50% (n = 17) had adenocarcinoma and 41% (n = 14) had squamous carcinoma. The majority (79%) received dCRT with a prescribed dose of 50 Gy in 25 fractions while the other 21% of patients were treated with radical radiotherapy alone (55 Gy in 20 fractions). The spleen was retrospectively contoured by one physician, and the V10 Gy and mean splenic dose (MSD) were calculated using Eclipse planning software. RESULTS: The median MSD was 14.4 Gy with a range of 0.75-28.3 Gy. The median V10 Gy was 62.7%. Of the cohort, 67.6% received an MSD of more than 10 Gy. CONCLUSIONS: Two-thirds of the patients received a dose of more than the 10 Gy. A review of the literature suggests that higher splenic radiation doses may increase the long-term risk of infection and impact on other outcomes. This study provides important evidence that the spleen receives a significant dose of radiation when treating distal oesophageal cancer and should be considered as an organ at risk.

Collaborative implementation of stereotactic ablative body radiotherapy: A model for the safe implementation of complex radiotherapy techniques in Australia.

INTRODUCTION: Stereotactic ablative radiotherapy (SABR) for lung cancer is a modality of treatment that has improved outcomes for lung cancer patients. However, radiotherapy for lung cancer is underutilized and fewer than half of elderly patients with non-small cell lung cancer (NSCLC) receive active treatment. The purpose of this study is to report on a collaboration in implementing an NSCLC SABR (stereotactic ablative body radiation) program safely, efficiently, and uniformly across several centers, including regional sites. The first aim of this paper is to detail the collaboration and implementation that started in 2013 and is ongoing. The second aim of this paper is to document early toxicities and quality of life outcomes. METHOD: A tripartite approach was used to develop the protocol and networks required for the implementation of SABR across multiple sites in NSW. Departments starting the programmes were supported and physics credentialing with central site submission was required before commencing the treatment. Additional ongoing support was available via an email discussion group involving all members of the collaboration. RESULTS: Between July 22, 2013 and February 22, 2016, 41 patients were enrolled with 34 patients in active follow up. The toxicity profile so far is similar to those of published studies with no appreciable effect on quality of life outcomes. CONCLUSION: The collaboration formed an effective framework in facilitating the implementation of SABR across several sites in NSW and could be used as a model for the safe and uniform implementation of new technologies in Australia.

Laryngeal tumours and radiotherapy dose to the cricopharyngeus are predictive of death from aspiration pneumonia.

OBJECTIVES: Aspiration pneumonia is an under-reported treatment sequelae following radiotherapy for head and neck cancer (HNC) patients. This study aims to investigate its incidence and risk factors in this population. MATERIALS AND METHODS: A retrospective review of all HNC patients that had received radiotherapy or chemo radiotherapy with radical intent at a single institution was undertaken (n=206). Dose delivered to the pharyngeal constrictors, base of tongue and cricopharyngeus was calculated and compared between those patients who had died from aspiration pneumonia and those who are alive or had died from other causes. RESULTS: In a cohort of 206 patients, the median time of follow up was 3.5years (IQR 1.8-4.9years). The cause of death was known in 80 and one of the leading causes of non-cancer related mortality was aspiration pneumonia (n=12) equating to an annual incidence of 0.016. Patients with a tumour located in the larynx had a higher risk of death compared to other sites (p=0.005). The mean cricopharyngeal dose was significantly higher in those patients who died of aspiration pneumonia (p=0.023) compared to those who were still alive or had died from other causes. In a multivariate regression analysis, maximum cricopharyngeal dose is a significant predictor of death from aspiration pneumonia. CONCLUSION: Dose to the cricopharyngeus and tumours located within the larynx is associated with an increased mortality due to aspiration pneumonia. Clinical awareness of high risk groups and more studies into causative nature are needed.

Quantitative Evaluation of Head and Neck Cancer Treatment-Related Dysphagia in the Development of a Personalized Treatment Deintensification Paradigm.

PURPOSE: To test the hypothesis that quantifying swallow function with multiple patient-reported outcome (PRO) instruments is an important strategy to yield insights in the development of personalized deintensified therapies seeking to reduce the risk of head and neck cancer (HNC) treatment-related dysphagia (HNCTD). METHODS AND MATERIALS: Irradiated HNC subjects seen in follow-up care (April 2015 to December 2015) who prospectively completed the Sydney Swallow Questionnaire (SSQ) and the MD Anderson Dysphagia Inventory (MDADI) concurrently on the web interface to our Oncospace database were evaluated. A correlation matrix quantified the relationship between the SSQ and MDADI. Machine-learning unsupervised cluster analysis using the elbow criterion and CLUSPLOT analysis to establish its validity was performed. RESULTS: We identified 89 subjects. The MDADI and SSQ scores were moderately but significantly correlated (correlation coefficient -0.69). K-means cluster analysis demonstrated that 3 unique statistical cohorts (elbow criterion) could be identified with CLUSPLOT analysis, confirming that 100% of variances were accounted for. Correlation coefficients between the individual items in the SSQ and the MDADI demonstrated weak to moderate negative correlation, except for SSQ17 (quality of life question). CONCLUSIONS: Pilot analysis demonstrates that the MDADI and SSQ are complementary. Three unique clusters of patients can be defined, suggesting that a unique dysphagia signature for HNCTD may be definable. Longitudinal studies relying on only a single PRO, such as MDADI, may be inadequate for classifying HNCTD.

Neoadjuvant hormone therapy for radical prostate radiotherapy: bicalutamide monotherapy vs. luteinizing hormone-releasing hormone agonist monotherapy: a single-institution matched-pair analysis.

BACKGROUND: The purpose of this study was to compare the prostate-specific antigen (PSA) response to either neoadjuvant bicalutamide (BC) monotherapy or neoadjuvant luteinizing hormone-releasing hormone agonist (LHRHa) monotherapy and the subsequent effect on biochemical failure-free survival (BFFS) in men receiving radical radiotherapy (RT) for localized prostate cancer. PATIENTS AND METHODS: This was a retrospective review of consecutive men treated with BC monotherapy before radical prostate RT who were individually case-matched to men treated with neoadjuvant LHRHa monotherapy. PSA kinetics and absolute pre-RT posthormone PSA (PRPH-PSA) level and subsequent BFFS were analyzed. RESULTS: Sixty-five men treated with BC monotherapy with a median follow-up of 44 months were individually matched with 65 men treated with LHRHa with a median follow-up of 54 months. Statistically significant differences were noted between groups in the PRPH-PSA, with a mean of 2.9 ng/mL (0.1-11.2 ng/mL) for patients receiving BC treatment and 1.8 ng/mL (0.1-11.1 ng/mL) for patients receiving LHRHa treatment (P < .001). A PRPH-PSA of < 1.0 and < 0.1 ng/mL was seen in 16 (24.6%) and 2 (3%) of the patients receiving BC and 34 (52.3%) and 3 (4.6%) patients receiving LHRHa, respectively. There were no significant differences between groups in either PSA halving time or velocity. Phoenix biochemical failure occurred in 10 (15.4%) and 8 (12.3%) patients receiving BC and patients receiving LHRHa, respectively. Neither PRPH-PSA level nor PSA kinetics during the neoadjuvant period predict for subsequent BFFS at this duration of follow-up. CONCLUSIONS: Although neoadjuvant BC therapy did not result in equivalent PRPH-PSA suppression when compared with neoadjuvant LHRHa alone, there was no difference in biochemical failure rates between cohorts at 50 months' median follow-up. Longer follow-up is required.