Clinical characterization of radiation-associated muscle-invasive bladder cancer.

OBJECTIVE: To characterize the presentation, patterns of care, and outcomes of radiation-associated muscle-invasive bladder cancer (RA-MIBC) compared to primary (non-radiation associated) MIBC. RA-MIBC has been suggested to represent a more aggressive disease variant and be more difficult to treat compared to primary (non-radiation associated) MIBC. METHODS: We identified 60,090 patients diagnosed with MIBC between 1988-2015 using the Surveillance, Epidemiology, and End Results database and stratified patients based on whether radiation had been administered to a prior pelvic primary cancer. We used Fine-Gray competing risks regression to compare adjusted bladder cancer-specific mortality (BCSM) for RA-MIBC compared to primary MIBC. RESULTS: There were 1,093 patients with RA-MIBC and 58,997 patients with primary MIBC. RA-MIBCs were more likely to be T4 at diagnosis (21.0% vs 17.3%, P < .001), and less likely to be node-positive (10.3% vs 17.1%, P < .001). The rate of 5-year BCSM was significantly higher for patients with RA-MIBC vs primary MIBC (56.1% vs 35.3%, AHR 1.24, P < .001), even after stratification by other tumor, treatment and patient-specific factors. CONCLUSION: RA-MIBCs tended to present with higher grade and T stage disease and were less likely to receive curative treatment. Even when accounting for stage, grade, and receipt of treatment, patients with RA-MIBC had worse survival compared to those with primary MIBC. These findings suggest that RA-MIBC present unique clinical challenges and may also represent a biologically more aggressive disease compared to primary MIBC. Future research is needed to better understand the biology of RA-MIBC and develop improved treatment approaches.

Quantitative-qualitative analyses of patient-reported pain response after palliative radiation therapy.

PURPOSE: While the 0-10 pain scale is often used to assess treatment response, it may not accurately reflect change in pain over time. The purpose of this study is to correlate pain improvement using the 0-10 pain scale to patients' perceived improvement in pain following palliative radiation therapy (RT), and to qualitatively characterize themes of pain assessment. METHODS: Patients age ≥ 20 receiving RT for spinal metastases were enrolled. Patients rated their pain (0-10) at the treatment site at RT start, and 1 and 4 weeks post-RT completion. At 1 and 4 weeks post-RT, patients reported their perceived percent improvement in pain (pPIP) (0-100%), which was compared to calculated percent improvement in pain (cPIP) based on the 0-10 pain scores. At 4 weeks post-RT, 20 randomly selected patients participated in a qualitative pain assessment. RESULTS: Sixty-four patients treated at 1-2 sites were analyzed. At 1 week post-RT completion, 53.7% (36/67) reported pPIP within 10 percentage points of cPIP, 32.8% (22/67) reported pPIP > 10 percentage points higher than cPIP, and 13.4% (9/67) reported pPIP > 10 percentage points lower than cPIP. Similar degrees of discordance were seen at 4 weeks post-RT. Qualitative analysis revealed five themes: pain quality (n = 19), activities (n = 9), function (n = 7), medication use (n = 2), and radiation side effects (n = 1). CONCLUSIONS: About half of patients reported a pPIP substantially disparate from their cPIP, and the change in pain measured by the 0-10 scale tended to underestimate the degree of perceived pain improvement. Multiple themes were identified in qualitative analysis of pain response.

A Multi-institutional Comparative Analysis of Proton and Photon Therapy-Induced Hematologic Toxicity in Patients With Medulloblastoma.

PURPOSE: This multi-institutional retrospective study sought to examine the hematologic effects of craniospinal irradiation (CSI) in pediatric patients with medulloblastoma using proton or photon therapy. METHODS AND MATERIALS: Clinical and treatment characteristics were recorded for 97 pediatric patients with medulloblastoma who received CSI without concurrent chemotherapy or with concurrent single-agent vincristine from 2000 to 2017. Groups of 60 and 37 patients underwent treatment with proton-based and photon-based therapy, respectively. Overall survival was determined by Kaplan-Meier curves with log-rank test. Comparisons of blood counts at each timepoint were conducted using multiple t tests with Bonferroni corrections. Univariate and multivariate analyses of time to grade ≥3 hematologic toxicity were performed with Cox regression analyses. RESULTS: Median age of patients receiving proton and photon CSI was 7.5 years (range, 3.5-22.7 years) and 9.9 years (range, 3.6-19.5 years), respectively. Most patients had a diagnosis of standard risk medulloblastoma, with 86.7% and 89.2% for the proton and photon cohorts, respectively. Median total dose to involved field or whole posterior fossa was 54.0 Gy/Gy relative biological effectiveness (RBE) and median CSI dose was 23.4 Gy/Gy(RBE) (range, 18-36 Gy/Gy[RBE]) for both cohorts. Counts were significantly higher in the proton cohort compared with the photon cohort in weeks 3 to 6 of radiation therapy (RT). Although white blood cell counts did not differ between the 2 cohorts, patients receiving proton RT had significantly higher lymphocyte counts throughout the RT course. Similar results were observed when excluding patients who received vertebral body sparing proton RT or limiting to those receiving 23.4 Gy. Only photon therapy was associated with decreased time to grade ≥3 hematologic toxicity on univariate and multivariable analyses. No difference in overall survival was observed, and lymphopenia did not predict survival. CONCLUSIONS: Patients who receive CSI using proton therapy experience significantly decreased hematologic toxicity compared with those receiving photon therapy.

Palliative radiotherapy for pediatric patients: Parental perceptions of indication, intent, and outcomes.

OBJECTIVES: Palliative radiation therapy (pRT) is often used to improve quality of life for pediatric patients. Though palliative doses are generally lower than those for cure, pRT may still introduce undesirable effects. The decision to pursue additional therapy for a child may be challenging and depends on parents' knowledge and expectations. The goal of this study was to explore parental perceptions of pRT. METHODS: Twenty-eight children referred for pRT were enrolled in our prospective study. Parents were counseled regarding the indication and expected outcomes. They then completed a series of questionnaires to assess their understanding of pRT, side effects that their child experienced, and how the outcomes compared to their expectations. RESULTS: The majority of parents listed pain relief and addressing new disease as the main indication for pRT. When asked about expectations, the majority chose improvement in quality of life and prolongation of their child's life. Interestingly, 32% of parents expected pRT to cure their child's disease. Most patients undergoing pRT did not experience any adverse symptoms. The outcomes of pRT in the majority of cases exceeded parental expectations. CONCLUSION: Improved quality of life with pRT sometimes blurs the distinction between palliation and cure. We found that most parents understand the aim to improve quality of life, although a proportion of parents perceived pRT as a cure to their child's disease. Despite this, the majority of parents reported that the outcome of the pRT course exceeded their expectations. We postulate that parents derive comfort from pursuing active treatment.

United States trends in active surveillance or watchful waiting across patient socioeconomic status from 2010 to 2015.

BACKGROUND: Prospective evidence supports active surveillance/watchful waiting (AS/WW) as an efficacious management option for low-risk prostate cancer that avoids potential treatment toxicity. AS/WW schedules require regular follow-up and adherence, and it is unknown to what extent patient socioeconomic status (SES) may impact management decisions for AS/WW. We sought to determine whether AS/WW use in the United States differs according to patient SES. DESIGN: Using the Surveillance, Epidemiology, and End Results Prostate with AS/WW Database, all adult men diagnosed with localized low-risk prostate cancer (clinical T1-T2a, Gleason 6, and prostate-specific antigen <10 ng/mL) and managed with either AS/WW, radical prostatectomy, or radiotherapy were identified between 2010 and 2015. SES tertile was measured by the validated Yost Index (low: 0-10,901; middle: 10,904-11,469; high: 11,470-11,827). AS/WW trends were defined across SES tertiles from 2010 to 2015. Logistic multivariable regression defined adjusted odds ratios (aOR) for receipt of AS/WW by SES tertile. RESULTS: In 50,302 men, AS/WW use was higher with increasing SES tertile (24.6, 25.3, and 30.5% for low, middle, and high SES tertiles, respectively; PTrend (SES) <0.001). From 2010 to 2015, AS/WW use in the low, middle, and high SES tertiles increased from 11.2 to 37.3%, 14.1 to 45.8%, and 17.6 to 46.4%, respectively (PTrends <0.001). By 2015, likelihood of AS/WW became comparable among the middle vs. high SES tertiles (aOR 0.96, 95% confidence interval (CI): 0.83-1.11, P = 0.55), but remained lower among the low vs. high SES tertile (aOR 0.73, 95% CI: 0.64-0.83, P < 0.001). CONCLUSIONS: AS/WW use for low-risk prostate cancer in the US differs by SES. Despite increases in AS/WW across SES from 2010 to 2015, patients from low SES received significantly lower rates of AS/WW compared with higher SES groups. SES may therefore influence management decisions, where factors associated with low SES might act as a barrier to AS/WW, and may need to be addressed to reduce any disproportionate risk of unnecessary treatment to lower SES patients.

Brainstem Injury in Pediatric Patients Receiving Posterior Fossa Photon Radiation.

PURPOSE: Brainstem necrosis is a rare, but dreaded complication of radiation therapy; however, data on the incidence of brainstem injury for tumors involving the posterior fossa in photon-treated patient cohorts are still needed. METHODS AND MATERIALS: Clinical characteristics and dosimetric parameters were recorded for 107 pediatric patients who received photon radiation for posterior fossa tumors without brainstem involvement from 2000 to 2016. Patients were excluded if they received a prescription dose <50.4 Gy, a brainstem maximum dose <50.4 Gy, or had fewer than 2 magnetic resonance imaging scans within 18 months after radiation. Post-radiation therapy magnetic resonance imaging findings were recorded, and brainstem toxicity was graded using National Cancer Institute Common Terminology Criteria for Adverse Events, version 5. RESULTS: The most common histologies were medulloblastoma (61.7%) and ependymoma (15.9%), and median age at diagnosis was 8.3 years (range, 0.8-20.7). Sixty-seven patients (62.6%) received craniospinal irradiation (median, 23.4 Gy; range, 18.0-39.6) as a component of their radiation therapy, and 39.3% and 40.2% of patients received an additional involved field or whole posterior fossa boost, respectively. Median prescribed dose was 55.8 Gy (range, 50.4-60.0). Median clinical and imaging follow-up were 4.7 years (range, 0.1-17.5) and 4.2 years (range, 0.1-17.3), respectively. No grade ≥2 toxicities were observed. The incidence of grade 1 brainstem necrosis was 1.9% (2 of 107). These patients were by definition asymptomatic and experienced resolution of imaging abnormality after 5.3 months and 2.1 years, respectively. CONCLUSIONS: Risk of brainstem necrosis was minimal in this multi-institutional study of pediatric patients treated with photon radiation therapy for tumors involving the posterior fossa with no cases of symptomatic brainstem injury, suggesting that brainstem injury risk is minimal in patients treated with photon therapy.