The dose distribution within the target was more homogenous, and the doses for healthy tissue were less in the FIF plan compared to the tangential wedge plans.
BackgroundWe aimed to study the predictive value of combined 18F-fluoro-deoxy-D-glucose positron emission tomography and computerized tomography (FDG-PET-CT), on outcomes in locally advanced pancreatic carcinoma (LAPC) patients treated with concurrent chemoradiotherapy (C-CRT).MethodsThirty-two unresectable LAPC patients received 50.4 Gy (1.8 Gy/fr) of RT and concurrent 5-FU followed by 4 to 6 cycles of gemcitabine consolidation. Response was evaluated by FDG-PET-CT at post-C-CRT 12-week. Patients were stratified into two groups according to the median difference between pre- and post-treatment maximum standard uptake values (SUVmax) as an indicator of response for comparative analysis.ResultsAt a median follow-up of 16.1 months, 16 (50.0%) patients experienced local/regional failures, 6 of which were detected on the first follow-up FDG-PET-CT. There were no marginal or isolated regional failures. Median pre- and post-treatment SUVmax and median difference were 14.5, 3.9, and -63.7%, respectively. Median overall survival (OS), progression-free survival (PFS), and local-regional progression-free survival (LRPFS) were 14.5, 7.3, and 10.3 months, respectively. Median OS, PFS, and LRPFS for those with greater (N = 16) versus lesser (N = 16) SUVmax change were 17.0 versus 9.8 (p = 0.001), 8.4 versus 3.8 (p = 0.005), and 12.3 versus 6.9 months (p = 0.02), respectively. On multivariate analysis, SUVmax difference was predictive of OS, PFS, and LRPFS, independent of existing covariates.ConclusionsSignificantly higher OS, PFS, and LRPFS in patients with greater SUVmax difference suggest that FDG-PET-CT-based metabolic response assessment is an independent predictor of clinical outcomes in LAPC patients treated with definitive C-CRT.
Background. Radiotherapy (RT) for abdominal and pelvic malignancies often causes severe small bowel toxicity. Citrulline concentrations are known to decrease with intestinal failure. We thus evaluated the feasibility of plasma citrulline levels in predicting radiation-induced intestinal toxicity. Material and methods. Fifty-three patients (36 prostate cancer, 17 endometrial cancer) who received 45 Gy pelvic RT using conventional fractionation were prospectively evaluated. Patients with prostate cancer received an additional 25-30.6 Gy conformal boost. Plasma citrulline levels were assessed on day 0, mid-(week 3) and post-RT (week 8), and four months post-RT. Dose-volume histogram, citrulline concentration changes, and weekly intestinal toxicity scores were analyzed. Results. Mean age was 63 years (range: 43-81 years) and mean baseline citrulline concentration was 38.0 Ϯ 10.1 μ mol/l. Citrulline concentrations were signifi cantly reduced at week 3 (27.4 Ϯ 5.9 μ mol/l; p Ͻ 0.0001), treatment end (29.9 Ϯ 8.8 μ mol/l; p Ͻ 0.0001), and four months post-treatment (34.3 Ϯ 12.1; p ϭ 0.01). The following factor pairs were signifi cantly positively correlated: Citrulline concentration/mean bowel dose during, end of treatment, and four months post-RT; dose-volume parameters/citrulline change groups; cumulative mean radiation dose/intestinal toxicity at end and four months post-RT; citrulline changes/intestinal toxicity during and end of RT. Citrulline concentration changes signifi cantly differed during treatment according to RTOG intestinal toxicity grades (p Ͻ 0.0001). Although the citrulline changes differed signifi cantly within RTOG intestinal toxicity grades (p ϭ 0.003), the difference between Grade 0 and Grade 1 did not differ signifi cantly at the end of the treatment. At four months after RT, no signifi cant differences were apparent. Conclusion. Citrulline-based assessment scores are objective and should be considered in measuring radiation-induced intestinal toxicity.
Background Access to cancer care is a problem that continues to plague refugees displaced from their home countries. The turbulent political crisis in Syria, which has led to millions of refugees seeking asylum in Turkey, merits further attention. We aimed to study the rate of utilization of radiation therapy among Syrian refugees with cancer living in Turkey in an attempt to identify the contributing factors predictive of non-compliance with prescribed RT. Methods In this retrospective review of 14 institutional databases, Syrian refugee patients in Turkey with a cancer diagnosis from January 2015 to December 2019 who were treated with RT were identified. The demographic data, treatment compliance rates, and toxicity outcomes in these patients were surveyed. Variable predictors of noncompliance such as age, sex, diagnosis, treatment length, and toxicity were studied. The association between these variables and patient noncompliance was determined. Results We identified 10,537 patients who were diagnosed with cancer during the study period, of whom 1010 (9.6%) patients were treated with RT. Breast cancer (30%) and lung cancer (14%) were the most common diagnoses with up to 68% of patients diagnosed at an advanced stage (Stage III, IV). 20% of the patients were deemed noncompliant. Treatment with concurrent chemoradiotherapy (OR 1.61, 95% CI 1.06–2.46, p = 0.023) and living in a refugee camp (OR 3.62, 95% CI 2.43–5.19, p < 0.001) were associated with noncompliance. Age, sex and treatment length were not significantly associated with noncompliance. Conclusions Noncompliance with radiotherapy among Syrian refugees in Turkey remains an area of concern with a multitude of factors contributing to these alarming numbers. Further studies to better ascertain the finer nuances of this intricately complex problem and a global combination of efforts can pave the way to providing a solution.
PurposeThe purpose of this study is to evaluate the correlation between the conventional plan parameters and dosimetric parameters obtained from conformal radiotherapy (RT) planning, and between these parameters and radiation pneumontitis (RP) incidence.MethodsClinical and dosimetric data of 122 patients that were treated with mastectomy and adjuvant 3D conformal RT (39% received 2-field RT [2-FRT], and in addition, 61% received 4-field RT [4-FRT]) were retrospectively analyzed. Central lung depth (CLD), maximum lung depth (MLD), and lung length were measured by the conventional plan. Lung dose-volume histograms (DVH) were created with conformal planning, and the lung volumes receiving 5 to 50 Gy (V5Gy to V50Gy) were calculated. Minimum (Dmin), maximum (Dmax), and mean doses (Dmean) for the ipsilateral lung and bilateral lungs were measured by DVH. Correlations between 3D dosimetric data and 2D radiographic parameters were analyzed.ResultsThe conventional plan parameters did not significantly differ between 2-FRT and 4-FRT. The conformal plan Dmin, Dmax, and Dmean values were higher in 4-FRT versus 2-FRT. CLD and MLD were correlated with DVH parameter V5Gy to V45Gy values for ipsilateral, as well as bilateral lungs for 2-FRT. MLD and ipsilateral Dmean via 2-FRT planning had the strongest positive correlation (r=0.76, p<0.01). Moderate correlations existed between CLD and ipsilateral and bilateral lung V5Gy-45Gy, and between MLD and bilateral lung V5Gy-45Gy values in 2-FRT. Only four patients developed symptomatic RP, 4 with 4-FRT and one with 2-FRT.ConclusionThe conformal plan parameters were strongly correlated with dose-volume parameters for breast 2-FRT. With only 4 cases of Grade 3 RP observed, our study is limited in its ability to provide definitive guidance, however assuming that CLD is an indicator for RP, V20Gy could be used as a predictor for RP and for 2-FRT. A well-defined parameters are still required to predict RP in 4-FRT.
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