Yee Ung

Phase II study assessing the effectiveness of Biafine cream as a prophylactic agent for radiation-induced acute skin toxicity to the breast in women undergoing radiotherapy with concomitant CMF chemotherapy

PURPOSEnTo assess the efficacy of Biafine cream in preventing Grade 2 acute radiation dermatitis, according to the National Cancer Institute of Canada skin radiation toxicity criteria in patients undergoing concomitant adjuvant chemotherapy and radiotherapy to the breast.nnnMETHODS AND MATERIALSnSixty patients participated in this study. Patients were treated with a lumpectomy followed by concomitant chemotherapy and radiotherapy to the breast. Biafine cream was applied daily, starting on the first day and ending 2 weeks post-radiotherapy. Patients underwent weekly skin assessments throughout radiotherapy and at 2 and 4 weeks after treatment. Outcome measures were assessed using a Skin Assessment Questionnaire that was scored according to the National Cancer Institute of Canada skin radiation toxicity criteria and a self-administered questionnaire that evaluated skin symptoms.nnnRESULTSnThe maximum skin toxicity observed during the course of treatment was as follows: less than Grade 2 toxicity, 15% (9 patients); Grade 2, 83% (50 patients); Grade 3, 2% (1 patient); Grade 4, 0% (0 patients). The majority of the radiation dermatitis was observed after 3 weeks of radiotherapy.nnnCONCLUSIONnThe majority of patients who underwent concomitant chemo- and radiotherapy for breast cancer developed Grade 2 radiation dermatitis with the use of Biafine cream. However, no treatment delays or interruptions were observed because of skin toxicity.

Comparison of the efficacy and acute toxicity of weekly versus daily chemoradiotherapy for non–small-cell lung cancer: a meta-analysis

PURPOSEnRecent studies have reported improved survival with concurrent chemoradiotherapy (ChRT) for inoperable non-small-cell lung cancer (NSCLC). ChRT includes the delivery of low-dose chemotherapy given daily during radiotherapy (RT) or higher doses administered weekly. It remains unknown whether a difference in efficacy or toxicity exists between these approaches. A systematic review was performed to compare the efficacy and toxicity of weekly vs. daily ChRT.nnnMETHODS AND MATERIALSnThe results from randomized studies comparing ChRT to RT for NSCLC were pooled using meta-analyses. The relative risk (RR) of death at 1, 2, and 3 years and of acute esophagitis, pneumonitis, or neutropenia (World Health Organization Grade 3 or greater) were determined.nnnRESULTSnTen studies involving 1802 patients were included. No significant difference in mortality or toxicity was observed between the weekly and daily regimens: RR of death at 2 years-weekly 0.93, 95% confidence interval [CI] 0.87-0.99; daily 0.92, 95% CI 0.85-1.00; RR of death at 3 years-weekly 0.93, 95% CI 0.89-0.98; daily 0.90, 95% CI 0.81-1.01; RR of esophagitis-weekly 2.07, 95% CI 0.96-4.46; daily 1.70, 95% CI 1.17-2.48; RR of pneumonitis-weekly 1.52, 95% CI 0.93-2.48; daily 1.17, 95% CI 0.65-2.09; and RR of neutropenia-weekly 8.57, 95% CI 3.75-19.58; daily 11.93, 95% CI 1.55-92.12.nnnCONCLUSIONnNo statistically significant difference in efficacy or acute toxicity was observed to suggest the superiority of daily vs. weekly ChRT regimens for NSCLC.

Improving Observer Variability in Target Delineation for Gastro-oesophageal Cancer—the Role of 18Ffluoro-2-deoxy-d-glucose Positron Emission Tomography/Computed Tomography

AIMnTo evaluate the effect of the addition of fused positron emission tomography-computed tomography (PET-CT) imaging vs computed tomography alone in the identification of the gross tumour volume (GTV) in patients with gastro-oesophageal carcinoma.nnnMATERIALS AND METHODSnTen patients with gastro-oesophageal cancer referred for radiation therapy underwent both (18F)fluoro-2-deoxy-d-glucose-PET (FDG-PET) and computed tomography in the treatment position. Image sets were anonymised and co-registered. Six radiation oncologists independently defined the GTV, first using the computed tomography data alone supplemented by standardised clinical and diagnostic imaging information, and second, using co-registered computed tomography and FDG-PET data (PET-CT). The standard deviation for both GTV length and volume (excluding involved lymph nodes) was taken as a measurement of inter-observer and intra-observer variability. Computer software that calculates volume overlap between contours was also used to generate an observer agreement index to compare intra- and inter-observer variability.nnnRESULTSnThe addition of FDG-PET imaging decreased the median standard deviation for tumour length from 10 mm (range 8.1-33.3, mean 12.4 mm) for computed tomography alone to 8mm (range 4.4-18.1, mean 8.1 mm) for PET-CT (P = 0.02). Eight of the 10 patients showed an increase in volume of overlap between observers with the addition of FDG-PET imaging to the contouring process (P = 0.05). The average observer agreement index in PET-CT was 72.7% compared with 69.1% when using computed tomography alone. There was significantly less intra-observer variability in all measures when PET-CT was used. The median standard deviation in length improved from 5.3 to 1.8 mm, the median standard deviation in volume improved from 4.5 to 3 cm3 and the median observer agreement index improved from 76.2 to 78.7% when computed tomography alone was compared with PET-CT. The corresponding P values were 0.001, 0.033 and 0.022, respectively.nnnCONCLUSIONSnThe addition of FDG-PET to computed tomography-based planning for the identification of primary tumour GTV in patients with gastro-oesophageal carcinoma decreases both inter-observer and intra-observer variability.

Automatic Segmentation of Lung Carcinoma Using 3D Texture Features in 18-FDG PET/CT

Target definition is the largest source of geometric uncertainty in radiation therapy. This is partly due to a lack of contrast between tumor and healthy soft tissue for computed tomography (CT) and due to blurriness, lower spatial resolution, and lack of a truly quantitative unit for positron emission tomography (PET). First-, second-, and higher-order statistics, Tamura, and structural features were characterized for PET and CT images of lung carcinoma and organs of the thorax. A combined decision tree (DT) with K-nearest neighbours (KNN) classifiers as nodes containing combinations of 3 features were trained and used for segmentation of the gross tumor volume. This approach was validated for 31 patients from two separate institutions and scanners. The results were compared with thresholding approaches, the fuzzy clustering method, the 3-level fuzzy locally adaptive Bayesian algorithm, the multivalued level set algorithm, and a single KNN using Hounsfield units and standard uptake value. The results showed the DTKNN classifier had the highest sensitivity of 73.9%, second highest average Dice coefficient of 0.607, and a specificity of 99.2% for classifying voxels when using a probabilistic ground truth provided by simultaneous truth and performance level estimation using contours drawn by 3 trained physicians.

Multisite stereotactic body radiotherapy for metastatic non-small-cell lung cancer: Delaying the need to start or change systemic therapy?

OBJECTIVESnThe purpose of this study was to review the clinical outcomes following the use of stereotactic body radiotherapy (SBRT) in patients with metastatic non-small-cell lung cancer (NSCLC) from a large academic institution.nnnMATERIALS AND METHODSnMetastatic NSCLC patients treated with extracranial SBRT were identified from an institutional database. Treatment indications were: (1) oligometastases, (2) oligoprogression, and (3) local control of dominant tumors. Endpoints included overall survival (OS), progression-free survival (PFS), time to starting/changing systemic therapy (SCST), and local failure (LF). Univariate and multivariable analyses were performed to look for predictive factors.nnnRESULTSn108 patients with 165 tumors were treated. SBRT was delivered for oligometastases in 66 patents, for oligoprogression in 20 patients, and for local control in 22 patients. Median OS and PFS for all patients were 27.3 months and 4.4 months, respectively, with treatment indication being the only predictive factor on multivariable analysis (patients with oligometastases having the highest median OS and PFS of 39.3 months and 7.6 months respectively). Cumulative incidence of SCST was only 21.5% at 1u2009year after SBRT, with larger tumor size and positivity for EGFR/ALK mutation being predictive of higher rates of SCST on multivariable analysis. LF was 15.6% at 1u2009year, with larger tumor size and exposure to previous systemic therapy being predictive of higher rates of LF on multivariable analysis.nnnCONCLUSIONnPatients treated with SBRT for oligometastases have better OS and PFS than those treated for oligoprogression or for local control of dominant tumors. Use of SBRT may delay the need for SCST. Larger tumors and previous exposure to systemic therapy were predictive of higher rates of LF.