Stereotactic body radiotherapy in the treatment of pancreatic adenocarcinoma in elderly patients.

BACKGROUND: Treatment of pancreatic adenocarcinoma in the elderly is often complicated by comorbidities that preclude surgery, chemotherapy and/or conventional external beam radiation therapy (EBRT). Stereotactic body radiotherapy (SBRT) has thus garnered interest in this setting. METHODS: A retrospective review of 26 patients of age ≥ 80 with pancreatic adenocarcinoma treated with definitive SBRT+/-chemotherapy from 2007-2011 was performed. Twenty-seven percent of patients were stage I, 38% were stage II, 27% were stage III and 8% were stage IV. Patients most commonly received 24 Gy/1 fraction or 30-36 Gy/3 fractions. Kaplan-Meier was used to estimate overall survival (OS), local control (LC), cause specific survival (CSS) and freedom-from-metastatic disease (FFMD). RESULTS: The median age was 86 (range 80-91), and median follow-up was 11.6 months (3.5-24.6). The median planning target volume was 21.48 cm3 (6.1-85.09). Median OS was 7.6 months with 6/12 month OS rates of 65.4%/34.6%, respectively. Median LC was 11.5 months, 6-month and 12-month actuarial LC rates were 60.1% and 41.2%, respectively. There were no independent predictors for LC, but there was a trend for improved LC with prescription dose greater than 20 Gy (p = 0.063). Median CSS was 6.3 months, and 6-month and 12-month actuarial CSS were 53.8% and 23.1%, respectively. Median FFMD was 8.4 months, and 6-month and 12-month actuarial rates were 62.0% and 41.4%, respectively. Nine patients (47%) had local failures, 11 (58%) had distant metastasis, and 7 (37%) had both. There were no acute or late grade 3+ toxicities. CONCLUSIONS: Definitive SBRT is feasible, safe and effective in elderly patients who have unresectable disease, have comorbidities precluding surgery or decline surgery.

Contouring inguinal and femoral nodes; how much margin is needed around the vessels?

PURPOSE: To determine the optimal margin needed around the femoral vessels for appropriate inguinofemoral lymph node coverage and to propose guidelines defined by anatomic boundaries for clinical target volume delineation. METHODS AND MATERIALS: Twenty-two patients with pelvic malignancies and involved inguinal lymph nodes treated with conformal radiation therapy were selected. Lymph nodes were considered positive if they were pathologically malignant by biopsy, had 1(8)F-fluorodeoxyglucose avidity on positron emission tomography or measured ≥1.5 cm on computed tomographic scan. We measured distance from the center of node(s) to the edge of the nearest femoral vessel. RESULTS: There were 52 total positive inguinal nodes among 22 patients. Relative to the femoral vessels, the location of the nodes were 51.9% anteromedial, 21.2% anterior, 11.5% anterolateral, 9.6% medial, 1.9% posterior, and 3.9% lateral. To cover ≥90% disease, the margins needed around the nearest femoral vessel were anteromedial ≥35 mm, anterior ≥23 mm, anterolateral ≥25 mm, medial ≥22 mm, posterior ≥9 mm, and ≥32 mm lateral. The corresponding anatomic boundaries were the following: laterally, medial border of the iliopsoas; medially, lateral border of adductor longus or medial end of pectineus; posteriorly, iliopsoas muscle laterally and anterior aspect of the pectineus muscle; medially and anteriorly, the anterior edge of the sartorius muscle. Most of the macroscopic nodes were medial or anteromedial to the femoral vessels. No patient had involved posterior or lateral nodes alone without positive nodes in the anterior or anteromedial positions. CONCLUSIONS: Circumferential margins around femoral vessels required to adequately cover this nodal region were >2 cm in most directions. Contouring the inguinal lymph nodes as a compartment defined by the anatomic landmarks suggested above may be more reproducible. Physicians should exercise caution in extrapolating pelvic nodal contouring guidelines to inguinal lymph nodal contouring.