D. Fried

Stage III Non–Small Cell Lung Cancer: Prognostic Value of FDG PET Quantitative Imaging Features Combined with Clinical Prognostic Factors

PURPOSE To determine whether quantitative imaging features from pretreatment positron emission tomography (PET) can enhance patient overall survival risk stratification beyond what can be achieved with conventional prognostic factors in patients with stage III non-small cell lung cancer (NSCLC). MATERIALS AND METHODS The institutional review board approved this retrospective chart review study and waived the requirement to obtain informed consent. The authors retrospectively identified 195 patients with stage III NSCLC treated definitively with radiation therapy between January 2008 and January 2013. All patients underwent pretreatment PET/computed tomography before treatment. Conventional PET metrics, along with histogram, shape and volume, and co-occurrence matrix features, were extracted. Linear predictors of overall survival were developed from leave-one-out cross-validation. Predictive Kaplan-Meier curves were used to compare the linear predictors with both quantitative imaging features and conventional prognostic factors to those generated with conventional prognostic factors alone. The Harrell concordance index was used to quantify the discriminatory power of the linear predictors for survival differences of at least 0, 6, 12, 18, and 24 months. Models were generated with features present in more than 50% of the cross-validation folds. RESULTS Linear predictors of overall survival generated with both quantitative imaging features and conventional prognostic factors demonstrated improved risk stratification compared with those generated with conventional prognostic factors alone in terms of log-rank statistic (P = .18 vs P = .0001, respectively) and concordance index (0.62 vs 0.58, respectively). The use of quantitative imaging features selected during cross-validation improved the model using conventional prognostic factors alone (P = .007). Disease solidity and primary tumor energy from the co-occurrence matrix were found to be selected in all folds of cross-validation. CONCLUSION Pretreatment PET features were associated with overall survival when adjusting for conventional prognostic factors in patients with stage III NSCLC.

Prognostic significance of bone invasion for oral cavity squamous cell carcinoma considered T1/T2 by American joint committee on cancer size criteria.

It is unclear whether bone invasion in small oral cavity squamous cell carcinomas (OCSCC) results in worse prognosis.

Costs of care in a matched pair comparison of intensity-modulated radiation therapy (IMRT) versus conventional radiation therapy (CRT) for the treatment of head and neck cancer.

Objectives:Intensity-modulated radiation therapy (IMRT) has been rapidly adopted for the treatment of head and neck cancer. Limited comparative effectiveness data suggest that IMRT reduces the incidence of xerostomia and improves quality of life. We assess the cost of IMRT versus the older conventional radiation therapy (CRT) relative to other potential drivers of cost in patients with head and neck cancer. Methods:We compared patients treated with definitive radiation with or without chemotherapy for squamous cell carcinoma of the head and neck treated between 2000 and 2009. IMRT-treated patients were matched to CRT-treated patients by site, stage, and smoking status. Itemized billing charges were obtained for each patient and used to estimate cost using the Medicare fee schedule. Multivariate analysis was used to assess the influence of demographic, clinical, and treatment variables on total, pretreatment, during treatment, and follow-up costs. Results:Models indicate that compared with CRT, IMRT was associated with, on average, a

Patterns of local failure for sinonasal malignancies

5881 increase in total costs (P=0.043), a

Dosimetric feasibility of sparing the primary site for oropharyngeal squamous cell carcinoma after transoral laser microsurgery in patients with unilateral positive neck nodes

1700 decrease in pretreatment costs (P=0.014), a

Incidence of subclinical nodal disease at the time of salvage surgery for locally recurrent head and neck cancer initially treated with definitive radiation therapy.

4768 increase in costs during treatment (P=0.004), and no significant difference in follow-up costs. Positron emission tomography scans, cancer recurrence, and comorbidity were also associated with higher total costs in this sample. Conclusions:Use of IMRT relative to CRT was strongly correlated with higher total costs, but disease control, patient comorbidity, and use of positron emission tomography also had significant effects on overall costs. Cost-effectiveness models should be developed to assess whether the potential benefits of IMRT are worth the associated investment.

Non–Small Cell Lung Cancer: Prognostic Importance of Positive FDG PET Findings in the Mediastinum for Patients with N0–N1 Disease at Pathologic Analysis

PURPOSE To identify the patterns of local failure for sinonasal malignancies treated with radiation therapy (RT). METHODS AND MATERIALS We retrospectively identified 79 patients with sinonasal malignancies treated between 2000 and 2011. The median follow-up was 34 months (7-137). Fifty patients (63%) had surgery and RT with or without chemotherapy, and 29 (37%) received definitive chemoradiation therapy. Twenty-six of 79 patients (33%) failed locally; 11 had persistent disease and 15 had local recurrence (LR). The patients with LR had at least a 3-month disease-free interval posttreatment. Imaging of the 15 LR was registered to the treatment planning computed tomography. Failures were categorized as in-field, marginal, or out-of-field if >95%, 20%-95%, or <20% of the LR was within the 95% prescription isodose line, respectively. RESULTS Of the 15 patients with LR, 7 were in-field, 2 were marginal, and 6 were out-of-field. For 3 patients, treatment plans were not retrievable; however, it was apparent from clinical records that 2 had in-field LR and 1 had an out-of-field LR (untreated contralateral maxillary sinus). No patient with a marginal or out-of-field recurrence had more than 39% of their recurrent tumor volume within 95% of the prescribed dose. Coverage of the LR by 54 Gy and 45 Gy was suboptimal in 7/7 and 5/7 patients with LR, respectively. Marginal and out-of-field LR were predominantly above the pretreatment tumor location and at the level of or superior to the eyes. CONCLUSIONS Sinonasal malignancies failed marginally or out-of-field in 53% (8/15) of LR and 31% (8/26) of all local failures. The anatomic location of these marginal and out-of field LR are predominately at, or superior to, the level of the eyes. This pattern of failure may be directly related to efforts to minimize RT to the optic structures and the degree of difficulty of skull base operations.

The incidence of radiation necrosis following stereotactic radiotherapy for melanoma brain metastases: The potential impact of immunotherapy

PURPOSE To quantify the effect of sparing the primary site after transoral laser microsurgery (TLM) for oropharyngeal squamous cell carcinoma (OPSCC). METHODS AND MATERIALS We reviewed 4 patients with OPSCC who were treated with TLM and postoperative radiation. All patients had T1 base of tongue primaries with the following N stages: 1 N1; 2 N2a; and 1 N2b. Three were lateralized to the right and 1 lateralized to the left. The primary site was not spared initially. We created new intensity modulated radiation treatment (IMRT) plans that spared the primary site. The prescribed dose to the high-risk (HR) and standard-risk (SR) planning target volumes (PTVs) was 60 Gy and 46 Gy at 2 Gy/fraction. PTV-SR and PTV-HR were adjusted to exclude the primary site. The primary site was maximally spared while maintaining similar PTV coverage and normal tissue avoidance as the initial plan. Dosimetric comparisons were made between the initial and primary-site sparing IMRT plans. RESULTS Dosimetric coverage of the PTVs and normal tissues (pharyngeal constrictors, contralateral parotid, etc) were comparable. The mean dose to the primary site was reduced by 20 Gy. The mean dose to the oral cavity was reduced by 25 Gy. CONCLUSIONS This study suggests that omitting the primary site from the radiation therapy target volume is unlikely to reduce long-term swallowing function to a meaningful degree in patients who receive radiation therapy following TLM for base of tongue cancer.

SU-E-J-261: The Importance of Appropriate Image Preprocessing to Augment the Information of Radiomics Image Features

Objectives/Hypothesis:To estimate the incidence of subclinical nodal disease at the time of isolated local recurrence (LR) after chemoradiotherapy for an initially staged N0 head and neck squamous cell carcinoma. Methods:We retrospectively reviewed 44 patients who underwent salvage surgery with or without elective neck dissection (END) for an isolated LR between 1997 and 2010. The incidence of subclinical nodal disease was determined from the pathology reports and from clinical neck failures. Results:Thirty patients received END. The overall incidence of subclinical nodal disease in patients with dissected necks was 10% (3/30 patients). The rate of regional control for the 14 observed necks was 100%. Three-year local control and overall survival rates for the END and non-END cohorts were 71% versus 73% (P=0.80) and 55% versus 64%, respectively (P=0.40). Conclusions:The risk of subclinical nodal disease is low for patients with an isolated LR after chemoradiotherapy.

Management of nonesthesioneuroblastoma sinonasal malignancies with neuroendocrine differentiation

PURPOSE To assess the prognostic implications of mediastinal positron emission tomographic (PET) findings in patients undergoing curative resection of non-small cell lung cancer (NSCLC) who have histologically negative mediastinal lymph nodes (LNs), with the hypothesis that positive findings at PET are prognostic even in patients with negative histologic findings in the LNs. MATERIALS AND METHODS Records of patients with a preoperative PET undergoing curative surgery, without adjuvant radiation, for pathologic T1-3N0-1 NSCLC at the University of North Carolina between 2000 and 2006 were reviewed as an institutional review board-approved HIPAA-compliant retrospective study. Ninety patients were evaluable (all histologically negative in mediastinum; 44 with both mediastinoscopy and surgery); 13 patients had positive mediastinal PET findings, and 77 had negative mediastinal PET findings. Local-regional and distant failure rates in patients with and those without mediastinal abnormalities at preoperative PET were compared by using logistic regression and log-rank tests. RESULTS Median follow-up was 54.3 months (range, 1-99 months). There were higher rates of local-regional (P = .001) and distant (P < .001) failure as well as death (P = .001) in patients with postive PET findings than in patients with negative findings. In multivariable analysis (adjusting for other prognostic factors), positive PET findings in the mediastinum remained prognostic for distant failure (P < .001, hazard ratio = 6.9) and were marginally prognostic for local-regional failure (P = .093, hazard ratio = 1.9). CONCLUSION Positive findings at preoperative PET in the mediastinum appear to have prognostic implications despite the mediastinal LNs being histologically negative. The high rate of local-regional and distant failure suggests that postoperative radiation therapy and/or chemotherapy may be particularly helpful in patients with positive mediastinal findings at preoperative PET.