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Chylothorax caused by superior vena cava (SVC) syndrome is a rare but potentially life-threatening complication requiring a multidisciplinary diagnosis and management approach. We present a case of a 27-year-old female with end-stage renal disease who developed chylothorax secondary to SVC syndrome caused by venous stenosis from a tunneled hemodialysis (HD) catheter. The patient had a history of ongoing hemodialysis through a tunneled catheter placed in the right internal jugular vein approximately seven months before presentation. She presented with dyspnea, chest pain, and a large left-sided pleural effusion. A multidisciplinary diagnostic workup and management included 2 thoracentesis, pleural fluid studies, serial radiological tests, right and left heart catheterizations, and blood serum studies with flow cytometry. They revealed that SVC stenosis around the hemodialysis catheter was causing the patient's pathology. The patient underwent veno-plasty of the right SVC and brachiocephalic veins and replacement of HD catheter leading to the resolution of the chylothorax and significant improvement in respiratory symptoms. This report will highlight the approach to diagnosing and managing chylothorax and a review of existing medical literature.

Purpose: To determine the dosimetric limitations of daily online adaptive pancreas stereotactic body radiation treatment by using an automated dose escalation approach. Methods and Materials: We collected 108 planning and daily computed tomography (CT) scans from 18 patients (18 patients × 6 CT scans) who received 5-fraction pancreas stereotactic body radiation treatment at MD Anderson Cancer Center. Dose metrics from the original non-dose-escalated clinical plan (non-DE), the dose-escalated plan created on the original planning CT (DE-ORI), and the dose-escalated plan created on daily adaptive radiation therapy CT (DE-ART) were analyzed. We developed a dose-escalation planning algorithm within the radiation treatment planning system to automate the dose-escalation planning process for efficiency and consistency. In this algorithm, the prescription dose of the dose-escalation plan was escalated before violating any organ-at-risk (OAR) dose constraint. Dose metrics for 3 targets (gross target volume [GTV], tumor vessel interface [TVI], and dose-escalated planning target volume [DE-PTV]) and 9 OARs (duodenum, large bowel, small bowel, stomach, spinal cord, kidneys, liver, and skin) for the 3 plans were compared. Furthermore, we evaluated the effectiveness of the online adaptive dose-escalation planning process by quantifying the effect of the interfractional dose distribution variations among the DE-ART plans. Results: The median D95% dose to the GTV/TVI/DE-PTV was 33.1/36.2/32.4 Gy, 48.5/50.9/40.4 Gy, and 53.7/58.2/44.8 Gy for non-DE, DE-ORI, and DE-ART, respectively. Most OAR dose constraints were not violated for the non-DE and DE-ART plans, while OAR constraints were violated for the majority of the DE-ORI patients due to interfractional motion and lack of adaptation. The maximum difference per fraction in D95%, due to interfractional motion, was 2.5 ± 2.7 Gy, 3.0 ± 2.9 Gy, and 2.0 ± 1.8 Gy for the TVI, GTV, and DE-PTV, respectively. Conclusions: Most patients require daily adaptation of the radiation planning process to maximally escalate delivered dose to the pancreatic tumor without exceeding OAR constraints. Using our automated approach, patients can receive higher target dose than standard of care without violating OAR constraints.

Purpose: Patients with pancreatic cancer often receive radiation therapy before undergoing surgical resection. We compared the clinical outcomes differences between stereotactic body radiation therapy (SBRT) and 3-dimensional (3D)/intensity-modulated radiation therapy (IMRT). Methods and Materials: We retrospectively collected data from the University of Texas MD Anderson Cancer Center. Patients with borderline resectable/potentially resectable or locally advanced pancreatic cancer receiving neoadjuvant SBRT (median, 36.0 Gy/5fx), 3D conformal radiation (median, 50.4 Gy/28 fx) or IMRT (median, 50.4 Gy/28 fx) were included. Overall survival (OS) and progression-free survival were analyzed using Cox regression. Results: In total, 104 patients were included in our study. Fifty-seven patients (54.8%) were treated with SBRT, and 47 patients (45.2%) were treated with 3D/IMRT. Patients in the SBRT group were slightly older (median age: 70.3 vs 62.7 in the 3D/IMRT group). Both groups had similar proportions of patients with locally advanced pancreatic cancer (SBRT: 30, 52.6%; 3D/IMRT: 24, 51.1%). All patients were treated with chemotherapy. Patients in the SBRT group underwent more surgical resection compared with the 3D/IMRT group (38.6% vs 23.4%, respectively). At a median follow-up of 22 months, a total of 60 patients (57.7%) died: 25 (25/57, 43.9%) in the SBRT group, and 35 (35/47, 74.5%) in the 3D/IMRT group. Median OS was slightly higher in the SBRT group (29.6 months vs 24.1 months in the 3D/IMRT group). On multivariable Cox regression, the choice of radiation therapy technique was not associated with differences in OS (adjusted hazard ratios [aHR] = 0.5; 95% confidence interval [CI], 0.2%-1.3%, P = .18). Moreover, patients that underwent surgical resection had better OS (aHR = 0.3, 95% CI, 0.1%-0.8%, P = .01). Furthermore, progression-free survival was also similar between patients treated with SBRT and those treated with 3D/IMRT (aHR = 0.9, 95% CI, 0.5%-1.8%, P = .81) Conclusions: SBRT was associated with similar clinical outcomes compared with conventional radiation techniques, despite being delivered over a shorter period of time which would spare patients prolonged treatment burden. Future prospective data are still needed to better assess the role of SBRT in patients with pancreatic cancer.

Purpose: Localized pancreatic cancer is commonly treated with stereotactic body radiation therapy (SBRT), which often requires the placement of fiducial markers. We compared the clinical outcomes of patients with and without fiducial markers. Methods and Materials: We retrospectively collected data on patients with pancreatic cancer treated with neoadjuvant SBRT at a single institution. Patients were divided into 2 groups based on the placement of a fiducial marker. Local recurrence was the primary outcome. Time to event endpoints were analyzed using COX regression. Results: We included 96 patients with unresectable pancreatic cancer: 46 patients (47.9%) did not have a fiducial marker, and 50 patients (52.1%) had a fiducial placed. Patients in the fiducial group were older and had more locally advanced pancreatic cancer compared with those who did not have a fiducial placed. Most patients in both groups (92.7%) received chemotherapy before SBRT treatment. SBRT was delivered to a median of 36 Gy over 5 fractions in the no-fiducial group, and 38 Gy over 5 fractions in the fiducial group. At a median follow-up of 20 months, local recurrence was similar irrespective of fiducial placement (adjusted hazard ratio [aHR] 0.6, 95% CI 0.3-1.3, P = .59). Furthermore, no difference in overall survival was noted between the 2 groups (aHR 0.8, 95% CI 0.3-1.9, P = .65). In patients who eventually underwent surgery post-SBRT, no difference in surgical margins (P = .40) or lymphovascular invasion (P = .76) was noted between the 2 groups. No patient developed acute pancreatitis after fiducial placement. Conclusions: Our data suggest that the use of fiducial markers does not negatively affect clinical outcomes in patients with localized pancreatic cancer. Prospective confirmation of our results is still needed.