RESUMO
Introduction: Adjuvant chemoradiation therapy (CRT) in gastric cancer inevitably results in an unintentional spleen radiation dose. We aimed to determine the association between the spleen radiation dose and the observed severity of lymphopenia which may affect the clinical outcomes (survival time and infection risk). Methods: Patients who received adjuvant CRT for gastric cancer between January 2015 and December 2020 were analyzed. The splenic dose-volume histogram (DVH) parameters were reported as mean splenic dose (MSD) and percentage of splenic volume receiving at least × Gray (Gy). Peripheral blood counts were recorded pre- and post-CRT. The development of severe (Common Terminology Criteria for Adverse Events, version 5.0, grade ≥ 3) post-CRT lymphopenia (absolute lymphocyte count [ALC] < 0.5 K/µL) was assessed by multivariable logistic regression using patient and dosimetric factors. Overall survival (OS), recurrence-free survival (RFS), and cumulative incidence of infectious events were estimated and analyzed using the Cox model or competing risk analysis. Results: Eighty-four patients with a median follow-up duration of 42 months were analyzed. Pre- and post-CRT median ALC values were 1.8 K/µL (0.9-3.1 K/µL) and 0.9 K/µL (0.0-4.9 K/µL), respectively (P < 0.001). MSD > 40 Gy (odds ratio [OR], 1.13; 95 % confidence interval [CI], 1.01-1.26; P = 0.041), sex (OR for male to female, 0.25; 95 % CI, 0.09-0.70; P = 0.008), and baseline absolute neutrophil count (OR per 1 unit increase, 1.61; 95 % CI, 1.02-2.58; P = 0.040) were associated with the development of severe post-CRT lymphopenia, which was a risk factor for poorer OS (hazard ratio [HR] = 2.47; 95 % CI, 1.24-4.92; P = 0.010) and RFS (HR = 2.27; 95 % CI, 1.16-4.46; P = 0.017). The cumulative incidence of infections was higher among severe post-CRT lymphopenia patients (2.53, 95 % CI, 1.03-6.23, P = 0.043). Conclusion: High splenic radiation doses increase the odds of severe post-CRT lymphopenia, an independent predictor of lower OS and higher risks of recurrence and infections in gastric cancer patients receiving adjuvant CRT. Therefore, optimizing the splenic DVH parameters may decrease the risk of severe post-CRT lymphopenia.
RESUMO
We developed a predictive score system for 30-day mortality after palliative radiotherapy by using predictors from routine electronic medical record. Patients with metastatic cancer receiving first course palliative radiotherapy from 1 July, 2007 to 31 December, 2017 were identified. 30-day mortality odds ratios and probabilities of the death predictive score were obtained using multivariable logistic regression model. Overall, 5,795 patients participated. Median follow-up was 39.6 months (range, 24.5-69.3) for all surviving patients. 5,290 patients died over a median 110 days, of whom 995 (17.2%) died within 30 days of radiotherapy commencement. The most important mortality predictors were primary lung cancer (odds ratio: 1.73, 95% confidence interval: 1.47-2.04) and log peripheral blood neutrophil lymphocyte ratio (odds ratio: 1.71, 95% confidence interval: 1.52-1.92). The developed predictive scoring system had 10 predictor variables and 20 points. The cross-validated area under curve was 0.81 (95% confidence interval: 0.79-0.82). The calibration suggested a reasonably good fit for the model (likelihood-ratio statistic: 2.81, P = 0.094), providing an accurate prediction for almost all 30-day mortality probabilities. The predictive scoring system accurately predicted 30-day mortality among patients with stage IV cancer. Oncologists may use this to tailor palliative therapy for patients.