Faculty Bibliography

BACKGROUND:Is posttreatment functional status prognostic of overall survival in patients with head and neck cancer (HNC). METHODS:In an HNC clinical trial, 495 patients had two posttreatment functional assessments measuring diet, public eating, and speech within 6 months. Patients were grouped by impairment (highly, moderately, modestly, or not impaired) and determined if they improved, declined, or did not change from the first assessment to the second. Multivariable Cox models estimated overall mortality. RESULTS:Across all three scales, the change in posttreatment patient function strongly predicted overall survival. In diet, patients who declined to highly impaired had three times the mortality of patients who were not impaired at both assessments (hazard ratio [HR] = 3.60; 95% confidence interval, 2.02-6.42). For patients improving from highly impaired, mortality was statistically similar to patients with no impairment (HR = 1.38; 95% CI, 0.82-2.31). CONCLUSIONS:Posttreatment functional status is a strong prognostic marker of survival in patients with HNC.

BACKGROUND:Small cohort studies have suggested oral tongue squamous cell carcinoma (OTSCC) could be associated with worse prognosis in individuals younger than 40. METHODS:We compared the survival of all OTSCC cases in the National Cancer Database under 40 years old with those older than 40, excluding patients over 70. Cox regression and propensity score matched (PSM) survival analyses were performed. RESULTS:A total of 22 930 OTSCC patients were identified. The under 40 group consisted of 2566 (9.9%) cases; 20664 were 40 to 70 (90.1%). Most were male (13 713, 59.8%), stage I-II (12 754, 72.4%), and treated by surgery alone (13 973, 63.2%). Survival in patients under 40 was higher (79.6% vs 69.5%, P < .001). In PSM analysis (n = 2928) controlling for all 10 significant factors in multivariate regression, patients under 40 had a 9% higher 5-year survival (77.1% vs 68.2%, P < .001). CONCLUSION/CONCLUSIONS:Contrary to the prior reports, younger patients with OTSCC did not have worse survival in the National Cancer Database.

Purpose: Concurrent chemotherapy with radiotherapy is the standard of care for locally advanced oropharyngeal cancer patients. However, the main drawback of this approach is the high toxicities experienced by the patients. This has motivated new clinical trials that investigate the role of imaging biomarkers in dose de-escalation to mitigate the side effects of treatments.
Method(s): Ten patients from an institutional phase II clinical trial were CE-CT (Contrast-Enhanced-CT) simulated prior to starting radiotherapy treatment and at week-four as part of the protocol. A radiation oncologist manually contoured the GTVn (primary nodal disease) on both scans. Based on GTVn volume variation (>=40%) patients were eligible/ineligible for dose de-escalation. CE-CT scans and contours were transfer to IBEX for texture-feature calculation. The relative net change for 77 texture-features was calculated. The Pearson correlation coefficient (r) was used to correlate the volume change with the feature changes. Texture-features that presented an r >0.5 are possible candidates for treatment assessment. Significance level was evaluated using the t-test (P < 0.05) Results: Eight patients met criteria for mid-treatment nodal response and were de-escalated. For the two patients who proceeded with standard treatment, shape texture-features variation were low, ranging [-6% to 14%] when compared to de-escalated patients range [-0% to 60%]. Across all the patients two shape features (surface area and surface area density) showed high correlation with node-tumor volume changes, with r-values of 0.81 (P < 0.05) and -0.66 (P < 0.05). Histogram-based-likeskewness showed a medium correlation with r-value of 0.52 (P > 0.05), whereas dissimilarity feature from the Gray-Level-Occurrence-Matrix showed correlation of 0.63 (P < 0.05).
Conclusion(s): Features with high Pearson correlation values are potential candidates to be used as additional metrics for treatment assessment. The study includes other imaging modalities (e.g MRI and PET) which will be included as a future work. More analysis will be added to the study as more patients are continually enrolled in the protocol

Purpose: The purpose of this study is to quantify interfractional dosimetric variations in radiotherapy of oropharyngeal cancer and investigate the application of statistical process control (SPC) to determine significantly deviated fractions for management.
Method(s): Thirteen oropharyngeal cancer patients treated by IMRT or VMAT with daily CBCT were retrospectively reviewed. CBCT images of every other fraction were imported to the software Velocity and registered to planning CT using the 6DOF couch shifts generated during patient setup. Using Velocity Adaptive Monitoring module, the setup-corrected CBCT was matched to planning CT using a deformable registration. The module also generated dose volume histograms (DVHs) at each CBCT from planning doses for the deformed plan structure sets. Volumes and dose metrics at each fraction were calculated and rated with plan values to evaluate interfractional dosimetric variations using a SPC framework. T-tests between plan and fraction volumes were performed to find statistically insignificant fractions. Average, upper and lower process capacity limits (UCL, LCL) of each dose metric were derived from these fractions using conventional SPC guidelines.
Result(s): GTV and OAR volumes in first 13 fractions had no significantly changes from the plan, subsequently reduced by 10% to treatment completion, except oral cavity. There were 3%-4% increases in parotid mean doses, but no significant differences in dose metrics of GTVand other OARs. The changes were organ and patient dependent. Control charts for various dose metrics were generated to assess the metrics for individual patient. The occurrences of one or several dose metrics out of the control limits warrant immediate investigation of the fraction.
Conclusion(s): Daily CBCT could be used to monitor dosimetric variations of targets and OARs resulting from volume changes and tissue deformation in oropharyngeal cancer radiotherapy. Treatment review with guidance of a SPC tool may enable objectively and consistently identify significantly deviated fractions