A 'short walk' is longer before radiotherapy than afterwards: a qualitative study questioning the baseline and follow-up design

<p>Abstract</p> <p>Background</p> <p>Numerous studies have indirectly demonstrated changes in the content of respondents' QoL appraisal process over time by revealing response-shift effects. This is the first known study to qualitatively examine the assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time. Specific objectives are to examine whether the content of each distinct cognitive process underlying QoL appraisal is (dis)similar over time and whether patterns of (dis)similarity can be discerned across and within patients and/or items.</p> <p>Methods</p> <p>We conducted cognitive think-aloud interviews with 50 cancer patients prior to and following radiotherapy to elicit cognitive processes underlying the assessment of 7 EORTC QLQ-C30 items. Qualitative analysis of patients' responses at baseline and follow-up was independently carried out by 2 researchers by means of an analysis scheme based on the cognitive process models of Tourangeau et al. and Rapkin & Schwartz.</p> <p>Results</p> <p>The interviews yielded 342 comparisons of baseline and follow-up responses, which were analyzed according to the five cognitive processes underlying QoL appraisal. The content of comprehension/frame of reference changed in 188 comparisons; retrieval/sampling strategy in 246; standards of comparison in 152; judgment/combinatory algorithm in 113; and reporting and response selection in 141 comparisons. Overall, in 322 comparisons of responses (94%) the content of at least one cognitive component changed over time. We could not discern patterns of (dis)similarity since the content of each of the cognitive processes differed across and within patients and/or items. Additionally, differences found in the content of a cognitive process for one item was not found to influence dissimilarity in the content of that same cognitive process for the subsequent item.</p> <p>Conclusions</p> <p>The assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time was not found to be in line with the cognitive processes described by the respondents. Additionally, we could not discern patterns of (dis)similarity across and within patients and/or items. In building on cognitive process models and the response shift literature, this study contributes to a better understanding of patient-reported QoL appraisal over time.</p

The effect of on-line position correction on the dose distribution in focal radiotherapy for bladder cancer

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to determine the dosimetric effect of on-line position correction for bladder tumor irradiation and to find methods to predict and handle this effect.</p> <p>Methods</p> <p>For 25 patients with unifocal bladder cancer intensity modulated radiotherapy (IMRT) with 5 beams was planned. The requirement for each plan was that 99% of the target volume received 95% of the prescribed dose. Tumor displacements from -2.0 cm to 2.0 cm in each dimension were simulated, using 0.5 cm increments, resulting in 729 simulations per patient. We assumed that on-line correction for the tumor was applied perfectly. We determined the correlation between the change in D_99%and the change in path length, which is defined here as the distance from the skin to the isocenter for each beam. In addition the margin needed to avoid underdosage was determined and the probability that an underdosage occurs in a real treatment was calculated.</p> <p>Results</p> <p>Adjustments for tumor displacement with perfect on-line position correction resulted in an altered dose distribution. The altered fraction dose to the target varied from 91.9% to 100.4% of the prescribed dose. The mean D_99%(± SD) was 95.8% ± 1.0%. There was a modest linear correlation between the difference in D_99%and the change in path length of the beams after correction (R²= 0.590). The median probability that a systematic underdosage occurs in a real treatment was 0.23% (range: 0 - 24.5%). A margin of 2 mm reduced that probability to < 0.001% in all patients.</p> <p>Conclusion</p> <p>On-line position correction does result in an altered target coverage, due to changes in average path length after position correction. An extra margin can be added to prevent underdosage.</p

Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer

<p>Abstract</p> <p>Background</p> <p>Results of high-dose chemo-radiotherapy (CRT), using the treatment schedules of EORTC study 08972/22973 or radiotherapy (RT) alone were analyzed among all patients (pts) with Non Small Cell Lung Cancer (NSCLC) treated with curative intent in our department from 1995–2004.</p> <p>Material</p> <p>Included are 131 pts with medically inoperable or with irresectable NSCLC (TNM stage I:15 pts, IIB:15 pts, IIIA:57 pts, IIIB:43 pts, X:1 pt).</p> <p>Treatment</p> <p>Group I: Concomitant CRT: 66 Gy/2.75 Gy/24 fractions (fx)/33 days combined with daily administration of cisplatin 6 mg/m²: 56 pts (standard).</p> <p>Group II: Sequential CRT: two courses of a 21-day schedule of chemotherapy (gemcitabin 1250 mg/m²d1, cisplatin 75 mg/m2 d2) followed by 66 Gy/2.75 Gy/24 fx/33 days without daily cisplatin: 26 pts.</p> <p>Group III: RT: 66 Gy/2.75 Gy/24 fx/33 days or 60 Gy/3 Gy/20 fx/26 days: 49 pts.</p> <p>Results</p> <p>The 1, 2, and 5 year actuarial overall survival (OS) were 46%, 24%, and 15%, respectively.</p> <p>At multivariate analysis the only factor with a significantly positive influence on OS was treatment with chemo-radiation (P = 0.024) (1-, 2-, and 5-yr OS 56%, 30% and 22% respectively). The incidence of local recurrence was 36%, the incidence of distant metastases 46%.</p> <p>Late complications grade 3 were seen in 21 pts and grade 4 in 4 patients. One patient had a lethal complication (oesophageal). For 32 patients insufficient data were available to assess late complications.</p> <p>Conclusion</p> <p>In this study we were able to reproduce the results of EORTC trial 08972/22973 in a non-selected patient population outside of the setting of a randomised trial. Radiotherapy (66 Gy/24 fx/33 days) combined with either concomitant daily low dose cisplatin or with two neo-adjuvant courses of gemcitabin and cisplatin are effective treatments for patients with locally advanced Non-Small Cell Lung Cancer. The concomitant schedule is also suitable for elderly people with co-morbidity.</p

Identifying Where REDD+ Financially Out Competes Oil Palm in Floodplain Landscapes Using a Fine-Scale Approach

Reducing Emissions from Deforestation and forest Degradation (REDD+) aims to avoid forest conversion to alternative land-uses through financial incentives. Oil-palm has high opportunity costs, which according to current literature questions the financial competitiveness of REDD+ in tropical lowlands. To understand this more, we undertook regional finescale and coarse-scale analyses (through carbon mapping and economic modelling) to assess the financial viability of REDD+ in safeguarding unprotected forest (30,173 ha) in the Lower Kinabatangan floodplain in Malaysian Borneo. Results estimate 4.7 million metric tons of carbon (MgC) in unprotected forest, with 64% allocated for oil-palm cultivations. Through fine-scale mapping and carbon accounting, we demonstrated that REDD+ can outcompete oil-palm in regions with low suitability, with low carbon prices and low carbon stock. In areas with medium oil-palm suitability, REDD+ could outcompete oil palm in areas with: very high carbon and lower carbon price; medium carbon price and average carbon stock; or, low carbon stock and high carbon price. Areas with high oil palm suitability, REDD + could only outcompete with higher carbon price and higher carbon stock. In the coarse-scale model, oil-palm outcompeted REDD+ in all cases. For the fine-scale models at the landscape level, low carbon offset prices (US $3 MgCO2e) would enable REDD+ to outcompete oil-palm in 55$27 million to secure these areas for 25 years. Higher carbon offset price (US $30 MgCO2e) would increase the competitiveness of REDD+ within the landscape but would still only capture between 69$380–416 million in carbon financing. REDD+ has been identified as a strategy to mitigate climate change by many countries (including Malaysia). Although REDD+ in certain scenarios cannot outcompete oil palm, this research contributes to the global REDD+ debate by: highlighting REDD+ competitiveness in tropical floodplain landscapes; and, providing a robust approach for identifying and targeting limited REDD+ funds

Actuarial overall survival of 131 patients treated with high dose accelerated radiotherapy with or without chemotherapy

<p><b>Copyright information:</b></p><p>Taken from "Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer"</p><p>http://www.ro-journal.com/content/2/1/27</p><p>Radiation Oncology (London, England) 2007;2():27-27.</p><p>Published online 23 Jul 2007</p><p>PMCID:PMC1947993.</p><p></p

Actuarial overall survival of patients treated with high-dose accelerated radiotherapy with concomitant chemotherapy, with sequential chemotherapy or without chemotherapy

<p><b>Copyright information:</b></p><p>Taken from "Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer"</p><p>http://www.ro-journal.com/content/2/1/27</p><p>Radiation Oncology (London, England) 2007;2():27-27.</p><p>Published online 23 Jul 2007</p><p>PMCID:PMC1947993.</p><p></p

Distant-metastasis free interval for 131 patients treated with accelerated high-dose radiotherapy with or without chemotherapy

<p><b>Copyright information:</b></p><p>Taken from "Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer"</p><p>http://www.ro-journal.com/content/2/1/27</p><p>Radiation Oncology (London, England) 2007;2():27-27.</p><p>Published online 23 Jul 2007</p><p>PMCID:PMC1947993.</p><p></p

Local-recurrence free interval for 131 patients treated with accelerated high-dose radiotherapy with or without chemotherapy

<p><b>Copyright information:</b></p><p>Taken from "Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer"</p><p>http://www.ro-journal.com/content/2/1/27</p><p>Radiation Oncology (London, England) 2007;2():27-27.</p><p>Published online 23 Jul 2007</p><p>PMCID:PMC1947993.</p><p></p