Changes in Non-Small Cell Lung Cancer Tumor Location Secondary to Gastric Distension, Implications in the Context of Stereotactic Body Radiation Therapy.

OBJECTIVE: Stereotactic body radiation therapy (SBRT) facilitates highly conformal dose distributions to a targe tumor volume. Accurate tumor localization is extremely important, and lung tumors pose a unique challenge due to respiratory motion. Patients are required to fast before PET/CT but not before CT simulation and daily treatment, introducing potential variability from gastric distension. METHODS: A case was reviewed involving a patient with early-stage NSCLC which was simulated and treated with SBRT. PET/CT performed while fasting showed an isolated left lower lobe lesion. Following CT simulation, CT and PET/CT images were superimposed for comparison and treatment planning. RESULTS: Tumor location variation was apparent following image superimposition. Simulation CT showed significant gastric distension compared to PET/CT. The patient was resimulated while fasting, resulting in accurate and reproducible tumor localization for treatment planning. CONCLUSIONS: Gastric distension can alter tumor location and treatment volumes for radiotherapy planning, possibly resulting in inaccurate treatment administration.

Phase II trial of vaginal cuff brachytherapy followed by chemotherapy in early stage endometrial cancer patients with high-intermediate risk factors.

OBJECTIVE: To determine the progression free survival (PFS), toxicity, and patterns of failure for early stage, high-intermediate risk (H-IR) patients in a phase II trial with adjuvant vaginal cuff brachytherapy (VCB) and three cycles of carboplatin and paclitaxel. METHODS: Surgically staged patients with stage I-IIb endometrial cancer with H-IR factors were treated with VCB (2100cGy) followed by three cycles of carboplatin (AUC 6) and paclitaxel (175 mg/m(2)). The primary endpoint was PFS at 2 years, with toxicity and sites of failure as secondary endpoints. Toxicity was assessed by patient report (CTCAE v. 3) as well as by delays or dose modifications in treatment. RESULTS: All patients completed VCB and 19/23 (83%) completed both VCB and 3 cycles of chemotherapy. Mean time to complete VCB was 14.5 days with minimal acute toxicity noted. At 6 months, all toxicity related to VCB had resolved. In total 60 cycles of chemotherapy were given, with one dose reduction (1.6%) for grade 2 neuropathy and seven delays (11.6%) in treatment due to hematologic toxicity. At a median follow-up of 44.5 months, 91% of patients remained progression free at 2 years. Four patients experienced a recurrence; they recurred both locally and distant. CONCLUSIONS: Adjuvant therapy with VCB and chemotherapy is well tolerated in a population of patients with H-IR endometrial carcinoma and provides 2 year PFS of 91%. A randomized trial is currently underway to assess whether combined VCB and chemotherapy reduces the rate of recurrence compared to external beam radiation therapy (EBRT) in this patient population.

Dosimetric comparison between IMRT delivery modes: Step-and-shoot, sliding window, and volumetric modulated arc therapy - for whole pelvis radiation therapy of intermediate-to-high risk prostate adenocarcinoma.

THIS STUDY WAS PERFORMED TO EVALUATE DOSIMETRIC DIFFERENCES BETWEEN CURRENT INTENSITY MODULATED RADIATION THERAPY (IMRT) DELIVERY MODES: Step-and-shoot (SS), sliding window (SW), and volumetric modulated arc therapy (VMAT). Plans for 15 prostate cancer patients with 10 MV photon beams using each IMRT mode were generated. Patients had three planning target volumes (PTVs) including prostate, prostate plus seminal vesicles, and pelvic lymphatics. Dose volume histograms (DVHs) of PTVs and organs at risk (OARs), tumor control probability (TCP) and normal tissue complication probabilities (NTCPs), conformation number, and monitor units (MUs) used were compared. Statistical analysis was performed using the analysis of variance (ANOVA) technique. The TCPs were < 99% with insignificant differences among modalities (P > 0.99). Doses to all critical structures were higher on average with SW method compared to SS, but insignificant. NTCP values were lowest for VMAT in all structures excepting bladder. Normal tissue volumes receiving doses in the 20-30 Gy range were reduced for VMAT compared to SS. Percentage of MUs required for VMAT to deliver a comparable plan to SS and SW was at least 40% less. In conclusion, similar target coverage and normal tissue doses were found by the three compared modes and the dosimetric differences were small.

The efficacy of radiotherapy in the treatment of orbital pseudotumor.

PURPOSE: To review institutional outcomes for patients treated with external-beam radiotherapy (EBRT) for orbital pseudotumor. METHODS AND MATERIALS: This is a single-institution retrospective review of 20 orbits in 16 patients diagnosed with orbital pseudotumor that received EBRT at the University of Oklahoma, Department of Radiation Oncology. Treated patients had a median follow-up of 16.5 months. RESULTS: Fifteen patients (93.7%) were initially treated with corticosteroids. Eight had recurrence after steroid cessation, six were unable to taper corticosteroids completely or partially, and one experienced progression of symptoms despite corticosteroid therapy. Fourteen patients (87.5%) initially responded to radiotherapy indicated by clinical improvement of preradiation symptoms and/or tapering of corticosteroid dose. Mean EBRT dose was 20 Gy (range, 14-30 Gy). Thirteen patients (81.2%) continued to improve after radiation therapy. Patient outcomes were complete cessation of corticosteroid therapy in nine patients (56.3%) and reduced corticosteroid dose in four patients (25%). Radiotherapy did not achieve long-term control for three patients (18.7%), who still required preradiation corticosteroid dosages. Three patients received retreatment(s) of four orbits, of which two patients achieved long-term symptom control without corticosteroid dependence. One patient received retreatment to an orbit three times, achieving long-term control without corticosteroid dependence. No significant late effects have been observed in retreated patients. CONCLUSIONS: Radiotherapy is an effective treatment for acute symptomatic improvement and long-term control of orbital pseudotumor. Orbital retreatment can be of clinical benefit, without apparent increase in morbidity, when initial irradiation fails to achieve complete response.

Results of phase I-II trial of concomitant hyperfractionated radiation and oral etoposide (VP-16) in patients with unresectable squamous cell carcinoma of the head and neck.

PURPOSE: The purpose of the current study was to investigate the efficacy of concomitant oral etoposide and hyperfractionated radiation for patients with unresectable head and neck squamous cell carcinoma. METHODS: A prospective nonrandomized phase I-II study was conducted using concomitant oral etoposide (50 mg/d for 13-27 days) and hyperfractionated radiotherapy (1.2 Gy twice daily to a total of 7440 rads) for patients with unresectable squamous cell carcinoma of the head and neck. Toxicity was graded according to the NCI common toxicity criteria. Patients were followed for a minimal period of 2 years. Endpoints for follow-up were recurrence or death. RESULTS: Seventeen patients were enrolled in the study. Grade III hematological toxicity occurred in 1 patient and moderate to severe mucositis occurred in all but 2 patients requiring a gastrostomy tube (n = 13) or intravenous fluids hydration (n = 2). One patient died of cardiac arrest unrelated to the treatment regimen. The overall response rates in patients that finished the protocol were 80% for the primary site and 100% for the neck. A complete response was observed in 47% at the primary site and 33% in the neck. Local control and disease-free survival (DFS) at an average follow-up of 3.7 years were 47% and 29%, respectively. CONCLUSIONS: Concomitant etoposide and hyperfractionated radiation is well tolerated and seems to be effective in the treatment of unresectable HNSCC with acceptable mucosal toxicity.