Minh-Phuong Huynh-Le

Low Interrater Reliability in Grading of Rectal Bleeding Using National Cancer Institute Common Toxicity Criteria and Radiation Therapy Oncology Group Toxicity Scales: A Survey of Radiation Oncologists

PURPOSE To measure concordance among genitourinary radiation oncologists in using the National Cancer Institute Common Toxicity Criteria (NCI CTC) and Radiation Therapy Oncology Group (RTOG) grading scales to grade rectal bleeding. METHODS AND MATERIALS From June 2013 to January 2014, a Web-based survey was sent to 250 American and Canadian academic radiation oncologists who treat prostate cancer. Participants were provided 4 case vignettes in which patients received radiation therapy and developed rectal bleeding and were asked for management plans and to rate the bleeding according to NCI CTC v.4 and RTOG late toxicity grading (scales provided). In 2 cases, participants were also asked whether they would send the patient for colonoscopy. A multilevel, random intercept modeling approach was used to assess sources of variation (case, respondent) in toxicity grading to calculate the intraclass correlation coefficient (ICC). Agreement on a dichotomous grading scale (low grades 1-2 vs high grades 3-4) was also assessed, using the κ statistic for multiple respondents. RESULTS Seventy-two radiation oncologists (28%) completed the survey. Forty-seven (65%) reported having either written or been principal investigator on a study using these scales. Agreement between respondents was moderate (ICC 0.52, 95% confidence interval [CI] 0.47-0.58) when using NCI CTC and fair using the RTOG scale (ICC 0.28, 95% CI 0.20-0.40). Respondents who chose an invasive management were more likely to select a higher toxicity grade (P<.0001). Using the dichotomous scale, we observed moderate agreement (κ = 0.42, 95% CI 0.40-0.44) with the NCI CTC scale, but only slight agreement with the RTOG scale (κ = 0.19, 95% CI 0.17-0.21). CONCLUSION Low interrater reliability was observed among radiation oncologists grading rectal bleeding using 2 common scales. Clearer definitions of late rectal bleeding toxicity should be constructed to reduce this variability and avoid ambiguity in both reporting and interpretation.

Use of standardized uptake value thresholding for target volume delineation in pediatric Hodgkin lymphoma

PURPOSE A limitation of [(18)F] 2-fluoro-2-deoxy-d-glucose positron emission tomography (FDGPET) in radiation planning for Hodgkin lymphoma (HL) is significant variability in delineation of tumor volume. One approach to reduce variability is to apply automatic or semiautomatic segmentation methods such as thresholding based on a percent tumor maximum standardized uptake value (SUVmax). Here, we apply various tumor SUVmax thresholds and examine their effects in involved field radiation therapy (IFRT) and involved site radiation therapy (ISRT) target volumes. METHODS AND MATERIALS PET/computed tomography data sets were reviewed for 16 pediatric and young adult patients treated with IFRT. The following percent tumor SUVmax thresholds were applied to the prechemotherapy PET: 15%, 20%, 25%, 30%, 35%, and 40%. Clinical target volumes for IFRT and ISRT plans were manually generated based on these threshold volumes (CTVPET) and compared with clinical target volumes generated using the standard qualitative visual method (CTVQVM). Treatment plans were generated, doses to normal structures were compared, and the optimum threshold, defined as the CTVPET that corresponded to the percent overlap closest to 100% when compared with the CTVQVM, was determined. RESULTS On average, there was a 7.6-fold increase in PET volume between 40% and 15% SUVmax. When the 6 SUVmax thresholds were applied in the design of target volumes for IFRT, 2 of 16 patients had a change in treatment volume. There was a 2.4-fold increase in ISRT CTVs generated based on the 15% and 40% SUVmax, which translated into a clinically significant decrease in dose to normal structures when the ISRT plans that were generated using the 15% SUVmax volumes were compared with the 40% SUVmax. In most patients, the optimum threshold was SUVmax 15%. CONCLUSIONS Accurate target volume delineation with [(18)F] 2-fluoro-2-deoxy-d-glucose PET in HL is challenging and may require more precise and reproducible segmentation methods as we move toward more conformal therapies.

Intensity Modulated Radiation Therapy Versus Conventional Radiation for Anal Cancer in the Veterans Affairs System

PURPOSE Compared with conventional radiation therapy, intensity modulated radiation therapy (IMRT) may reduce acute toxicity from anal cancer treatment, potentially leading to improved long-term outcomes. We analyze the effect of IMRT on short- and long-term outcomes among a large sample of US veterans. METHODS AND MATERIALS From a national Veterans Affairs database, we identified 779 patients (n = 403 conventional radiation therapy, n = 376 IMRT) with locally advanced anal squamous cell carcinoma diagnosed between 2000 and 2015 and treated with concurrent chemoradiation therapy. Radiation treatment planning and dosimetric constraints were not standardized across patients. We analyzed the effect of IMRT on short-term outcomes (acute toxicity, treatment breaks, and incomplete chemotherapy) and long-term outcomes (survival and ostomy placement) in multivariable logistic regression, Fine-Gray, and frailty models, adjusting for potential confounders. RESULTS IMRT was associated with decreased radiation treatment breaks ≥5 days (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.37-0.91; P = .02), increased rates of receiving 2 cycles of mitomycin C chemotherapy (OR 2.04; 95% CI 1.22-3.45; P = .007), increased rates of receiving 2 cycles of any chemotherapy (OR 3.45; 95% CI 1.82-6.25; P < .001), and decreased risk of ostomy related to tumor recurrence or progression (subdistribution hazard ratio 0.60; 95% CI 0.37-0.99; P = .045). IMRT was not associated with a decrease in grade 3 to 4 hematologic toxicity (P = .79), hospitalization for gastrointestinal toxicity (P = .59), or cancer-specific survival (P = 0.18). CONCLUSIONS Among a large sample of US veterans with anal cancer, IMRT was associated with higher rates of receiving 2 chemotherapy cycles, decreased radiation treatment breaks, and decreased rates of ostomy placement. IMRT appears to offer substantial benefits over conventional radiation therapy for patients undergoing concurrent chemoradiation therapy for anal cancer.

Patterns of failure after involved field radiation therapy for pediatric and young adult Hodgkin lymphoma

Involved field radiation therapy (IFRT) is integral in curative therapy for Hodgkin lymphoma (HL), although primarily used in patients with intermediate/high‐risk HL. We present failure patterns and clinical outcomes in a cohort of pediatric and young adult patients with HL treated with IFRT at the Johns Hopkins Hospital.

Association of HIV Status With Outcomes of Anal Squamous Cell Carcinoma in the Era of Highly Active Antiretroviral Therapy

This study uses data from the Veterans Affairs database to examine the association of HIV status with outcomes in patients with anal cancer.