Sio, Terence T.

Small-cell lung cancer (SCLC) has a high predilection for metastasizing to the brain after chemotherapy. This has been blamed on the blood-brain barrier, which prevents chemotherapy from penetrating into the brain, thus creating a sanctuary site. It has been estimated that up to three quarters of patients with SCLC will eventually develop brain metastases. This led investigators to administer prophylactic cranial irradiation (PCI) to decrease this risk. Several trials were performed in patients with SCLC after initial therapy (chemotherapy with or without thoracic radiotherapy) that compared the outcomes of PCI versus no PCI. Early trials generally found that PCI significantly decreased the risk of brain metastases but did not significantly improve survival. These trials were re-evaluated in two larger meta-analyses that included patients with either limited-stage SCLC or extensive-stage SCLC (ESCLC). Both meta-analyses reported that PCI significantly decreased brain metastases and improved survival in patients who had a complete response following initial therapy. These studies were performed before the advent of modern imaging with computed tomography or magnetic resonance imaging (MRI). There have been two modern trials of PCI versus no PCI in patients with ESCLC and both found that PCI decreases brain metastases. The first did not include brain MRI before registration and found that PCI improved survival, whereas the second study did include MRI before registration and at frequent intervals thereafter. That trial found that PCI did not confer a survival advantage. This review will examine the evidence and provide recommendations regarding the role of PCI for patients with ESCLC.

PurposeTo implement and evaluate a novel and fast method for proton range verification by using a planar scintillator and step wedge.MethodsA homogenous proton pencil beam plan with 35 energies was designed and delivered to a 2D flat scintillator with a step wedge. The measurement was repeated 15 times (3 different days, 5 times per day). The scintillator image was smoothed, the Bragg peak and distal fall off regions were fitted by an analytical equation, and the proton range was calculated using simple trigonometry. The accuracy of this method was verified by comparing the measured ranges to those obtained using an ionization chamber and a scanning water tank, the gold standard. The reproducibility was evaluated by comparing the ranges over 15 repeated measurements. The sensitivity was evaluated by delivering to same beam to the system with a film inserted under the wedge.ResultsThe range accuracy of all 35 proton energies measured over 3 days was within 0.2 mm. The reproducibility in 15 repeated measurements for all 35 proton ranges was ±0.045 mm. The sensitivity to range variation is 0.1 mm for the worst case. This efficient procedure permits measurement of 35 proton ranges in less than 3 min. The automated data processing produces results immediately. The setup of this system took less than 5 min. The time saving by this new method is about two orders of magnitude when compared with the time for water tank range measurements.ConclusionsA novel method using a scintillator with a step wedge to measure the proton range was implemented and evaluated. This novel method is fast and sensitive, and the proton range measured by this method was accurate and highly reproducible.

The purpose of the present study was to compare the impact of pulmonary function, body habitus, and stereotactic body radiation therapy (SBRT) immobilization on setup and reproducibility for upper lung tumor. From 2008 through 2011, our institution's prospective SBRT database was searched for patients with upper lung tumors. Two SBRT immobilization strategies were used: full‐length BodyFIX and thermoplastic S‐frame. At simulation, free‐breathing, four‐dimensional computed tomography was performed. For each treatment, patients were set up to isocenter with in‐room lasers and skin tattoos. Shifts from initial and subsequent couch positions with cone‐beam computed tomography (CBCT) were analyzed. Accounting for setup uncertainties, institutional tolerance of CBCT‐based shifts for treatment was 2, 2, and 4 mm in left–right, anterior–posterior, and cranial–caudal directions, respectively; shifts exceeding these limits required reimaging. Each patient's pretreatment pulmonary function test was recorded. A multistep, multivariate linear regression model was performed to elucidate intervariable dependency for three‐dimensional calculated couch shift parameters. BodyFIX was applied to 76 tumors and S‐frame to 17 tumors. Of these tumors, 41 were non–small cell lung cancer and 15 were metastatic from other sites. Lesions measured , 1.1 to 2 (50%), 2.1 to 3 (25%), and cm. Errors from first shifts of first fractions were significantly less with S‐frame than BodyFIX (). No difference in local control (LC) was found between S‐frame and BodyFIX (); two‐year LC rate was 94%. Multivariate modeling confirmed that the ratio of forced expiratory volume in the first second of expiration to forced vital capacity, body habitus, and the immobilization device significantly impacted couch shift errors. For upper lung tumors, initial setup was more consistent with S‐frame than BodyFIX, resulting in fewer CBCT scans. Patients with obese habitus and poor lung function had more SBRT setup uncertainty; however, outcome and probability for LC remained excellent.PACS number: 89.20.‐a

The authors compared the relative dosimetric merits of Gamma Knife (GK) and CyberKnife (CK) in 15 patients with 26 brain metastases. All patients were initially treated with the Leksell GK 4C. The same patients were used to generate comparative CK treatment plans. The tissue volume receiving more than 12 Gy (V12), the difference between V12 and tumor volume (V12net), homogeneity index (HI), and gradient indices (GI25, GI50) were calculated. Peripheral dose falloff and three conformity indices were compared. The median tumor volume was 2.50 cm3 (range, 0. 044‐19.9). A median dose of 18 Gy (range, 15‐22) was prescribed. In GK and CK plans, doses were prescribed to the 40‐50% and 77‐92% isodose lines, respectively. Comparing GK to CK, the respective parametric values were: minimum dose ( vs. , ); mean dose ( vs., ); maximum dose ( vs., ); and HI ( vs. , ). The median dosimetric indices (GK vs. CK, with range) were: RTOG_CI, 1.76 (1.12‐4.14) vs. 1.53 (1.16‐2.12), ; CI, 1.76 (1.15‐4.14) vs. 1.55 (1.18‐2.21), ; nCI, 1.76 (1.59‐4.14) vs. 1.57 (1.20‐2.30), ; GI50, 2.91 (2.48‐3.67) vs. 4.90 (3.42‐11.68), ; GI25, 6.58 (4.18‐10.20) vs. 14.85 (8.80‐48.37), . Average volume ratio (AVR) differences favored GK at multiple normalized isodose levels . We concluded that in patients with brain metastases, CK and GK resulted in dosimetrically comparable plans that were nearly equivalent in several metrics, including target coverage and minimum dose within the target. Compared to GK, CK produced more homogenous plans with significantly lower mean and maximum doses, and achieved more conformal plans by RTOG_CI criteria. By GI and AVR analyses, GK plans had sharper peripheral dose falloff in most cases.PACS number: 89.20.‐a

97 Background: A diagnosis of EC significantly impairs patient (pt)’s survival and quality of life (QoL). We explored the relationship between pt-assessed QoL and survival. Methods: The Mayo Clinic Romero (formerly Esophageal Adenocarcinoma-Barrett's Esophagus) Registry prospectively collects clinical data during a pt's treatment course. QoL is recorded at enrollment (baseline) and annually using a validated 12-item Linear Analog Self-Assessment (LASA). A 10-pt scale is applied; ≤5 was termed clinically deficient QoL. Initial TNM staging, clinical (age, sex, prior chemotherapy, and esophagectomy), and socioeconomic variables (marital/employment status) were analyzed using Cox proportional hazards regression models. Results: 836 pts were analyzed. Median age was 64 years. 166, 506 and 164 pts had early, locally advanced, and metastatic EC, with 5-year survival rates of 75.1%, 33.6%, and 8.1%, respectively (P≤.0001). Poorer survival rates were seen in clinically QoL deficient pts in the following categories: Overall QoL (Hazard Ratio [H.R.] 0.66; 95% C.I., 0.54-0.80; P≤.0001) and LASA subsets for physical (H.R. 0.68; 95% C.I., 0.57-0.82; P≤.0001), emotional well-being (H.R. 0.69; C.I., 0.57-0.84; P=.0003), and social activity (H.R. 0.76; C.I., 0.63-0.91; P=.0028). No difference in survival was observed for marital or employment status, familial support, and financial/legal concerns. Pts with esophagectomy prior to LASA evaluation had improved survival (H.R. 0.68; 95% C.I., 0.55-0.85; P=.0005). No survival difference was observed whether pts received chemotherapy, before or after their baseline LASA evaluation. Conclusions: A strong association exists between pt’s overall survival and better overall QOL, physical, emotional well-being, and social activities. Using LASA to clinically monitor QoL at specified intervals may afford providers the opportunity to intervene when patients begin to experience QoL decline. The determinants of clinically deficit QoL and its impact on survival warrant further translational and prospective research.

Abstract GNE-317 is a dual PI3K/mTOR inhibitor with excellent blood-brain barrier penetration. In this study, the efficacy of GNE-317 was evaluated in the Mayo panel of primary glioblastoma multiforme (GBM) xenografts. Based on the concept of oncogene addiction, we hypothesized that GNE-317 would be most efficacious in EGFR-hyper-activated and/or PTEN-deficient lines. In a CyQUANT cell proliferation assay, the inhibitory concentration of 50% cell number (IC50) for GBM6, 10, 22, and 84 were 0.59±0.50, 0.72±0.40, 0.26±0.14, and 3.49±1.64 microM, respectively. In these selected lines, there was a poor correlation between EGFR or PTEN status and in vitro response. The efficacy of GNE-317 also was evaluated in 10 lines in an orthotopic xenograft model. Mice with established tumors were randomized to daily dosing with GNE-317 (30 mg/kg) or placebo until moribund. Similar to in vitro data, there was a spectrum of response to GNE-317 (Table 1). The survival benefit ratio (ratio of median survival) did not correlate with EGFR amplification (P=0.78), EGFR mutation (P=0.25), or PTEN (P=0.55) status when analyzed singly. However, GNE-317 did extend survival in 4 of 5 lines in which either EGFR or PTEN were deregulated. To evaluate potentially clinically relevant combinations, the efficacy of GNE-317 combined with bevacizumab (BEV) was tested in the same orthotopic model in GBM8, 10, and 59. In GBM10, GNE-317/BEV provided a significant increase in survival compared to the most effective single agent (P<0.0001). In GBM8, 10, and 59, the ratio of median survival for GNE-317/BEV vs. placebo were 1.47, 1.75, and 1.74, respectively (all P≤0.01). In conclusion, there may be a correlation between deregulation of the EGFR/PTEN signaling network and GNE-317 efficacy, and the efficacy of GNE-317 in some models can be extended when combined with bevacizumab. Table 1:Molecular Characteristics and Efficacy of GNE-317 in Mayo Primary GBM XenograftsEGFR AmplifiedEGFR vIII MutatedPTEN MutatedGNE-317 Responder*Benefit Ratio** of GNE-317GBM6YesYesWTYes1.35GBM8YesNoYes, HDYes1.19GBM10NoNoYes, HDYes1.47GBM22NoNoWTNo0.85GBM59YesYesYes, HDYes1.27GBM84YesNoYes, del Exon 1No1.02GBM115NoNoTBDNo0.86GBM116NoNoTBDNo1.05GBM117NoNoTBDYes1.38GBM122YesNoTBDNo0.99Abbreviations: HD=homozygous deleted; del=deletion in; TBD=to be determined; WT=wild type.* If in vivo survival difference reached P<0.05 by Log-rank Kaplan-Meier method between the GNE-317 treated and placebo groups, the GBM line was classified as a responder to GNE-317.** The benefit ratio equals to median survival of the GNE-317 treated group, divided by that of the placebo group. Note: This abstract was not presented at the meeting. Citation Format: Terence T. Sio, Jenny L. Pokorny, Ann C. Mladek, Brett L. Carlson, Mark A. Schroeder, Dennis O. Iyekegbe, Katrina Bakken, Laurent Salphati, Heidi Phillips, Jann N. Sarkaria. Preclinical efficacy of GNE-317, a dual PI3K/mTOR inhibitor, with or without bevacizumab in EGFR and/or PTEN-mutated glioblastoma multiforme. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2617. doi:10.1158/1538-7445.AM2014-2617

Objectives: The aim of this was to determine survival after starting neoadjuvant therapy for patients who became ineligible for orthotopic liver transplantation (OLT). Methods and Materials: Since January 1993, 215 patients with unresectable cholangiocarcinoma began treatment with planned OLT. Treatment included external-beam radiation therapy (EBRT) with fluorouracil, bile duct brachytherapy, and postradiotherapy fluorouracil or capecitabine before OLT. Adverse findings at the staging operation, death, and other factors precluded OLT in 63 patients (29%), of whom 61 completed neoadjuvant chemoradiation. Results: By October 2012, 56 (89%) of the 63 patients unable to undergo OLT had died. Twenty-two patients (35%) became ineligible for OLT before the staging operation, 38 (60%) at the staging operation, and 3 (5%) after staging. From the date of diagnosis, median overall survival was 12.3 months. Survival was 17% at 18 months and 7% at 24 months. Median survival after fallout was 6.8 months. Median survival after the staging operation was 6 months. Two patients lived for 3.7 and 8.7 years before dying of cancer or liver failure caused by persistent biliary stricture at the site of the original cancer, respectively. Univariate analysis showed that time from diagnosis to fallout correlated with overall survival (P=0.04). Conclusions: In highly selected patients initially suitable for OLT, the mortality rate for cholangiocarcinoma was high in patients who became ineligible for OLT. Their survival, however, was comparable to expected survival for patients with locally advanced or metastatic disease treated with nontransplant therapies. The most common reason for patient fallout was adverse findings at the staging operation.

Objectives: To determine long-term outcomes in patients with locally advanced esophageal carcinoma treated with trimodality therapy (chemoradiotherapy [CRT] and surgery, TMT) or definitive CRT. Methods: We retrospectively identified patients with advanced esophageal carcinoma treated with curative intent at our institution between 1998 and 2004. Identified patients were separated into 3 groups: patients who received TMT, patients who received CRT, and patients who began treatment with trimodality intent but did not undergo surgery (PTMT). Local control, overall survival (OS), and distant metastasis-free survival were compared using Kaplan-Meier statistics. Results: Among the 265 patients included, median follow-up was 6.4 years for surviving patients and 1.7 years for all patients. Type of esophageal cancer was adenocarcinoma in 213 patients (80%) and squamous cell carcinoma in 46 patients (17%). Treatment groups comprised 169 patients (64%) completing TMT, 46 patients medically unable to undergo surgery after neoadjuvant therapy (PTMT), and 50 (19%) who underwent CRT. Median OS was 20.5 months; actuarial 5- and 10-year OS were 27% and 12%, respectively. The TMT group had the highest 5- and 10-year OS (32% and 19%, respectively). Local control rates at 2, 5, and 10 years for all patients were 80%, 70%, and 69%, respectively. By treatment modality, 5-year local control was best (82%) for TMT, compared with 60% for CRT and 40% for PTMT groups (P<0.001). Conclusions: Patients who completed TMT had the best local control and long-term OS. In the context of TMT, surgery seemed more beneficial in patients with esophageal adenocarcinoma versus squamous cell carcinoma.