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Purpose: The primary objective was to compare 3’-deoxy-3’-(18F) fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) uptake in 3 cohorts of stereotactic body radiation therapy (SBRT) patients: (1) pre-SBRT, (2) stable post-SBRT lung fibrosis, and (3) suspicious or proven local recurrence post-SBRT. The secondary objectives were to optimize FLT-PET imaging by comparing FLT uptake in respiratory-gated (4-dimensional) versus nongated (3-dimensional) FLT-PET scans. Methods: Patients with early-stage non-small cell lung cancer planned or treated with SBRT at the institution with radiographic findings of fibrosis or recurrence were eligible for the study. All patients underwent imaging with FLT-PET/CT before SBRT in cohort 1 and at fibrosis or recurrence in cohort 2 and 3, respectively. The planned sample size was 20 patients in each cohort, with 60 patients total. FLT-PET standardized uptake value (SUV) variables including SUVmax, SUVmean, SUVpeak, SUV50, and SUV95 were compared among the 3 cohorts using the Kruskal-Wallis test. The correlation of respiratory-gated and nongated FLT-PET SUV variables was performed using the Spearman correlation coefficient. Results: Forty-one patients were recruited for the study (20 in cohort 1, 16 in cohort 2, and 5 in cohort 3) between 2015 and 2019. The majority received a diagnosis of stage I lung cancer (86%), and the most common prescription was 48 Gy in 4 fractions (59%). Respiratory-gated FLT-PET was performed in 35 patients. The FLT SUV variables were well correlated between respiratory-gated and nongated scans (r = 0.8-1.0). The SUVpeak, SUVmean, and SUVmax were significantly lower in the fibrosis cohort compared with the recurrence and pretreatment cohorts. The SUV50 and SUV95 values in the recurrence cohort were statistically similar to the pretreatment cohort. Conclusions: FLT-PET/CT may be helpful in differentiating SBRT-related fibrosis from recurrence. Nongated FLT-PET/CT with reporting of SUVmax and SUV95 values is recommended.

Purpose: With multiple phase 2 trials supporting the use of stereotactic body radiation therapy (SBRT) in oligo-metastatic disease, we evaluated practices that could inform effective implementation of an oligo-metastasis SBRT program. Methods and Materials: Using a context-focused realist methodology, an advisory committee of interprofessional clinicians met over a series of semistructured teleconference meetings to identify challenges in implementing an oligo-metastasis SBRT program. Consideration was given to 2 models of care: a subspecialist anatomic expertise model versus a single-practitioner “quarterback” model. Results: The advisory committee structured recommendations within a context-mechanism-outcome framework. In summary, the committee recommends that during patient workup, a single practitioner arranges the minimum number of necessary tests, with case presentation at an appropriate multidisciplinary tumor board, including careful review of all previous treatments, and enrollment on clinical trials when possible. At simulation, common patient positions and immobilization on a single simulation scan for multiple sites is recommended. During radiation planning, dose-fractionation regimens should safely facilitate cumulative dose calculations, a single isocenter should be considered for multiple close targets to reduce treatment time, and adherence to strict quality assurance protocols is strongly recommended. Treatment duration should be minimized by treating multiple sites on the same day or choosing shorter dose fractionations. Team communication, thorough documentation, and standardized nomenclature can reduce system errors. Follow-up should aim to minimize redundant clinical appointments and imaging scans. Expert radiology review may be required to interpret post-SBRT imaging. Conclusions: These guidelines inform best clinical practices for implementing an oligo-metastasis SBRT program. Iterations using a realist approach may further expand on local contexts.

Objective To identify any association between type 2 diabetes mellitus (T2DM) and survival outcomes for mucosal squamous cell carcinoma of the head and neck. An association has been demonstrated between T2DM and cancer outcomes at numerous sites, but data for the head and neck are limited. Improving our understanding of the impact that diabetes has on head and neck cancer survival is relevant for making treatment decisions and counseling patients regarding prognosis. Study Design Retrospective cohort study. Setting Academic tertiary referral head and neck cancer center. Subjects and Methods By accessing data retrospectively from prospectively collected databases at the Princess Margaret Cancer Centre, patients were studied who were treated for mucosal head and neck squamous cell cancer between January 2005 and December 2011. Collection of clinical, pathologic, and survival data was completed with an emphasis on T2DM. Results Of 2498 patients identified in the study period, 319 (12.8%) had T2DM. Five-year overall survival was not different between the diabetic (64%, 95% CI = 58%-71%) and nondiabetic (67%, 95% CI = 65%-69%; P = .078) groups. Furthermore, cause-specific survival did not demonstrate a statistically significant difference between groups (diabetic: 84%, 95% CI = 79%-88%, vs nondiabetic: 84%, 95% CI = 82%-86%; P = .67). Conclusion Despite contradictory evidence at other cancer sites, the presence of T2DM alone does not appear to adversely affect cancer survival outcomes in head and neck squamous cell cancer. This is encouraging for the diabetic patients with head and neck squamous cell cancer, and it provides guidance for the multidisciplinary team that treats them. [ABSTRACT FROM AUTHOR]