A pragmatic contouring guideline for salivary gland structures in head and neck radiation oncology: the MOIST target.

OBJECTIVES: One of the main normal tissue toxicities in head and neck radiation oncology is xerostomia. In several studies, reduced radiation dose to the salivary glands has been shown to diminish the effects of gland dysfunction. However, no clear guidelines exist to define the anatomic location of the involved glands on cross-sectional imaging in a pragmatic manner. This study presents an anatomic, computed tomography (CT)-based definition of the major and minor salivary glands. METHODS: On the basis of information from normal structure anatomy, the location of major and minor salivary glands was identified and translated into a cross-sectional CT-based description of the salivary glands. RESULTS: The major salivary glands include the parotids and submandibular glands. The minor salivary glands are presented as a part of a surrogate structure (the Minor Oral Including Sublingual Salivary Tissue target), including the minor glands located in the oral mucosa of the tongue, hard and soft palate, buccal mucosa, and inner surface of the lips. CONCLUSIONS: Clinical implementation of CT-based delineations of the salivary glands according to the proposed guideline should reduce interobserver variability. This may lead to an improved understanding of the relationship between radiation dose and volume and effects on salivary function.

A randomized controlled trial of lorazepam to reduce liver motion in patients receiving upper abdominal radiation therapy.

PURPOSE: Reduction of respiratory motion is desirable to reduce the volume of normal tissues irradiated, to improve concordance of planned and delivered doses, and to improve image guided radiation therapy (IGRT). We hypothesized that pretreatment lorazepam would lead to a measurable reduction of liver motion. METHODS AND MATERIALS: Thirty-three patients receiving upper abdominal IGRT were recruited to a double-blinded randomized controlled crossover trial. Patients were randomized to 1 of 2 study arms: arm 1 received lorazepam 2 mg by mouth on day 1, followed by placebo 4 to 8 days later; arm 2 received placebo on day 1, followed by lorazepam 4 to 8 days later. After tablet ingestion and daily radiation therapy, amplitude of liver motion was measured on both study days. The primary outcomes were reduction in craniocaudal (CC) liver motion using 4-dimensional kV cone beam computed tomography (CBCT) and the proportion of patients with liver motion ≤5 mm. Secondary endpoints included motion measured with cine magnetic resonance imaging and kV fluoroscopy. RESULTS: Mean relative and absolute reduction in CC amplitude with lorazepam was 21% and 2.5 mm respectively (95% confidence interval [CI] 1.1-3.9, P=.001), as assessed with CBCT. Reduction in CC amplitude to ≤5 mm residual liver motion was seen in 13% (95% CI 1%-25%) of patients receiving lorazepam (vs 10% receiving placebo, P=NS); 65% (95% CI 48%-81%) had reduction in residual CC liver motion to ≤10 mm (vs 52% with placebo, P=NS). Patients with large respiratory movement and patients who took lorazepam ≥60 minutes before imaging had greater reductions in liver CC motion. Mean reductions in liver CC amplitude on magnetic resonance imaging and fluoroscopy were nonsignificant. CONCLUSIONS: Lorazepam reduces liver motion in the CC direction; however, average magnitude of reduction is small, and most patients have residual motion >5 mm.

Postoperative intensity-modulated radiotherapy following surgery for oral cavity squamous cell carcinoma: patterns of failure.

OBJECTIVES: To review outcomes and analyze the patterns of locoregional recurrence of oral cavity squamous cell carcinoma (OCSCC) treated with surgery and postoperative intensity-modulated radiation therapy (IMRT). MATERIALS AND METHODS: All patients with Stage I-IVB OCSCC treated with surgery and postoperative IMRT± concurrent chemotherapy between 2005 and 2010 were evaluated. Patient survival and tumor outcomes were prospectively recorded. Outcome measures were 2 year overall survival (OS), local control (LC), regional control (RC) and distant control (DC). Locoregional recurrences were spatially localized in relation to dosimetric plans. RESULTS: A total of 180 consecutive patients with median follow-up of 34 months were identified. Disease subsites were oral tongue (46%), floor of mouth (23%), alveolus and hard palate (12%), buccal (9%), retromolar trigone (5%), and lip (4%). The 2 year rates of OS, LC, RC, locoregional control (LRC), and DC were 65%, 87%, 83%, 78% and 83%, respectively. The 2-year estimated rates of LRC for larger subsites were: oral tongue (72%), floor of mouth (84%). Of the 180 patients, 38 (21%) had locoregional failure (LRF). Most LRFs were in-field (26, 68%) with 7 marginal and 5 out-of-field. Marginal/out-of-field failures occurred in the contralateral neck in N2b patients, at high level II/skull base, and in intentionally spared regions (near parotid) of pathologically involved necks. CONCLUSIONS: Nearly a third (12/38) of LR recurrences were marginal or out-of-field following postoperative IMRT for OCSCC. Postoperative IMRT following gross total surgical resection requires careful and comprehensive target volume delineation, and larger volumes may be needed than the primary RT setting.