First clinical experience with real-time portal imaging-based breath-hold monitoring in tangential breast radiotherapy.

Background and purpose: Real-time treatment monitoring with the electronic portal imaging device (EPID) can conceptually provide a more accurate assessment of the quality of deep inspiration breath-hold (DIBH) and patient movement during tangential breast radiotherapy (RT). A system was developed to measure two geometrical parameters, the lung depth (LD) and the irradiated width (named here skin distance, SD), along three user-selected lines in MV EPID images of breast tangents. The purpose of this study was to test the system during tangential breast RT with DIBH. Materials and methods: Measurements of LDs and SDs were carried out in real time. DIBH was guided with a commercial system using a marker block. Results from 17 patients were assessed. Mean midline LDs, , per tangent were compared to the planned mLDs; differences between the largest and smallest observed () per tangent were calculated. Results: For 56% (162/288) of the tangents tested, were outside the tolerance window. All but one patient had at least one fraction showing this behaviour. The largest difference found between an and its planned mLD was -16.9 mm. The accuracy of patient positioning and the quality of marker-block-based DIBH guidance contributed to the differences. Fractions with patient position verification using a single EPID image taken before treatment showed a lower rate (34%), suggesting reassessment of setup procedures. Conclusions: Real-time treatment monitoring of the internal anatomy during DIBH delivery of tangential breast RT is feasible and useful. The new system requires no additional radiation for the patient.

International comparison of cosmetic outcomes of breast conserving surgery and radiation therapy for women with ductal carcinoma in situ of the breast.

PURPOSE: To assess the cosmetic impact of breast conserving surgery (BCS), whole breast irradiation (WBI) fractionation and tumour bed boost (TBB) use in a phase III trial for women with ductal carcinoma in situ (DCIS) of the breast. MATERIALS AND METHODS: Baseline and 3-year cosmesis were assessed using the European Organization for Research and Treatment of Cancer (EORTC) Cosmetic Rating System and digital images in a randomised trial of non-low risk DCIS treated with postoperative WBI +/- TBB. Baseline cosmesis was assessed for four geographic clusters of treating centres. Cosmetic failure was a global score of fair or poor. Cosmetic deterioration was a score change from excellent or good at baseline to fair or poor at three years. Odds ratios for cosmetic deterioration by WBI dose-fractionation and TBB use were calculated for both scoring systems. RESULTS: 1608 women were enrolled from 11 countries between 2007 and 2014. 85-90% had excellent or good baseline cosmesis independent of geography or assessment method. TBB (16 Gy in 8 fractions) was associated with a >2-fold risk of cosmetic deterioration (p < 0.001). Hypofractionated WBI (42.5 Gy in 16 fractions) achieved statistically similar 3-year cosmesis compared to conventional WBI (50 Gy in 25 fractions) (p ≥ 0.18). The adverse impact of a TBB was not significantly associated with WBI fractionation (interaction p ≥ 0.30). CONCLUSIONS: Cosmetic failure from BCS was similar across international jurisdictions. A TBB of 16 Gy increased the rate of cosmetic deterioration. Hypofractionated WBI achieved similar 3-year cosmesis as conventional WBI in women treated with BCS for DCIS.

Correction of systematic setup errors in prostate radiation therapy: how many images to perform?

The purpose of this study was to develop an evidence-based off-line setup correction protocol for systematic errors in prostate radiation therapy. Daily orthogonal electronic portal images were acquired from 30 patients. Field displacements were measured in the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) directions for each treatment fraction. The off-line protocol corrects the mean field displacement found from n consecutive images, starting at a particular fraction of treatment, with a fixed tolerance level. Simulations were performed with the measured data to determine (1) how many images (n) should be averaged to determine the systematic error; (2) on which treatment fraction should the protocol be initiated; and (3) what tolerance level should be applied to determine whether the patient position should be corrected. Uncorrected systematic errors in the ML, SI, and AP directions were (mean position +/- 1 standard deviation [SD]): -0.7 +/- 2.2 mm, -1.5 +/- 1.3 mm, and 1.4 +/- 2.6 mm, respectively. Random errors (1 SD and range) were 1.9 mm (1.3 - 3.3), 1.5 mm (0. - 4.1), and 1.8 mm (1.0-2.6), respectively. A correction based on a single image taken on the first fraction actually increased the systematic errors in the ML and SI directions compared with no correction. More accurate correction of systematic errors was achieved with increasing number of images averaged, with only small benefit after 5 images. With fewer images averaged, delaying the start of the protocol resulted in more accurate correction because of the influence of unrepresentative positions at early fractions. The number of corrections made on patients with small (< 2 mm) systematic errors was minimized for tolerance values of 2 mm and n > or = 5 images averaged. The optimal off-line setup correction protocol would be to shift the patient by the mean displacement of the first 5 portal images of a radical course of radiation therapy. A small tolerance level should be utilized with 2 mm giving good accuracy with minimal unnecessary shifts.

Do age and comorbidity impact treatment allocation and outcomes in limited stage small-cell lung cancer? a community-based population analysis.

PURPOSE: The effects of age and comorbidity on treatment and outcomes for patients with limited stage small-cell lung cancer (L-SCLC) are unclear. This study analyzes relapse and survival in a community-based population with L-SCLC according to age and comorbidity. METHODS: A retrospective review was performed on 174 patients with L-SCLC referred to the British Columbia Cancer Agency, Vancouver Island Centre, between January 1991 and December 1999. Patient and treatment characteristics, disease response, relapse, and survival were compared among three age cohorts: <65 years (n = 55, 32%), 65-74 years (n = 76, 44%), and > or =75 years (n = 43, 25%); and according to Charlson comorbidity scores 0, 1, and > or =2. Multivariate analysis was performed to identify independent prognostic factors associated with treatment response and survival. RESULTS: Patient factors that significantly differed with age were functional status classified by Eastern Cooperative Oncology Group performance status and number of comorbidities. Increasing age was significantly associated with fewer diagnostic scans. Combined modality chemoradiotherapy (CRT) was given in 86%, 66%, and 40% of patients ages <65, 65-74, and > or =75 years, respectively, (p <0.0001). Thoracic irradiation use was comparable among the age cohorts (p >0.05), but chemotherapy use varied significantly with less intensive regimens, fewer cycles, and lower total doses with advancing age (p <0.05). Prophylactic cranial irradiation (PCI) was used in 41 patients, only 3 of whom were age >70 years. Overall response rates to primary treatment significantly decreased with advancing age: 91%, 79%, and 74% in patients ages <65, 65-74, and > or =75 years, respectively (p = 0.014). Treatment toxicity and relapse patterns were similar across the age cohorts. Overall 2-year survival rates were significantly lower with advancing age: 37%, 22%, and 19% (p = 0.003), with corresponding median survivals of 17, 12, and 7 months among patients ages <65, 65-74, and > or =75 years, respectively. On multivariate analysis, age and Charlson comorbidity scores were not significantly associated with treatment response and survival. Independent prognostic factors favorably associated with survival were good performance status, normal lactate dehydrogenase, absence of pleural effusion, and > or =four cycles of chemotherapy. CONCLUSION: Increasing age was associated with decreased performance status and increased comorbidity. Older patients with L-SCLC were less likely to be treated with CRT, intensive chemotherapy, and PCI. Treatment response and survival rates were lower with advancing age, but this may be attributed to poor performance status and suboptimal treatment rather than age.