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A standardized checklist is optimal for patients' chart check

Kim, Leonard; Chen, Ting; Rong, Yi
PMCID:5689881
PMID: 28291916
ISSN: 1526-9914
CID: 2931972

Long-Term Bone Marrow Suppression During Postoperative Chemotherapy in Rectal Cancer Patients After Preoperative Chemoradiation Therapy

Newman, Neil B; Sidhu, Manpreet K; Baby, Rekha; Moss, Rebecca A; Nissenblatt, Michael J; Chen, Ting; Lu, Shou-En; Jabbour, Salma K
PURPOSE/OBJECTIVE(S)/OBJECTIVE:To quantify ensuing bone marrow (BM) suppression during postoperative chemotherapy resulting from preoperative chemoradiation (CRT) therapy for rectal cancer. METHODS AND MATERIALS/METHODS:We retrospectively evaluated 35 patients treated with preoperative CRT followed by postoperative 5-Fluorouracil and oxaliplatin (OxF) chemotherapy for locally advanced rectal cancer. The pelvic bone marrow (PBM) was divided into ilium (IBM), lower pelvis (LPBM), and lumbosacrum (LSBM). Dose volume histograms (DVH) measured the mean doses and percentage of BM volume receiving between 5-40 Gy (i.e.: PBM-V5, LPBM-V5). The Wilcoxon signed rank tests evaluated the differences in absolute hematologic nadirs during neoadjuvant vs. adjuvant treatment. Logistic regressions evaluated the association between dosimetric parameters and ≥ grade 3 hematologic toxicity (HT3) and hematologic event (HE) defined as ≥ grade 2 HT and a dose reduction in OxF. Receiver Operator Characteristic (ROC) curves were constructed to determine optimal threshold values leading to HT3. RESULTS:During OxF chemotherapy, 40.0% (n=14) and 48% (n=17) of rectal cancer patients experienced HT3 and HE, respectively. On multivariable logistic regression, increasing pelvic mean dose (PMD) and lower pelvis mean dose (LPMD) along with increasing PBM-V (25-40), LPBM-V25, and LPBM-V40 were significantly associated with HT3 and/or HE during postoperative chemotherapy. Exceeding ≥36.6 Gy to the PMD and ≥32.6 Gy to the LPMD strongly correlated with causing HT3 during postoperative chemotherapy. CONCLUSIONS:Neoadjuvant RT for rectal cancer has lasting effects on the pelvic BM, which are demonstrable during adjuvant OxF. Sparing of the BM during preoperative CRT can aid in reducing significant hematologic adverse events and aid in tolerance of postoperative chemotherapy.
PMID: 27026312
ISSN: 1879-355x
CID: 2932102

Real patient data based cross verification of kilovoltage and megavoltage CT calibration for proton therapy

Nishioka, Shie; Park, Joo Han; Zou, Wei; Zhang, Miao; Yue, Ning J; Chen, Ting
PURPOSE/OBJECTIVE:We propose a methodology to evaluate the stoichiometric calibration method on MVCT against the corresponding kVCT calibration using patient data. METHODS:Stoichiometric calibrations were conducted for a MVCT and a kVCT scanner, respectively. We retrospectively analyzed kVCT and MVCT images of 21 patients by picking small tissue volumes in kVCT images and performing image registration to locate the tissue volumes in corresponding MVCT images. We computed the difference between the mean proton stopping power derived through kVCT and MVCT calibration, taking into account the uncertainties in calibration, imaging, and image registration. RESULTS:kVCT and MVCT calibration curves were in good agreement for soft tissues such as muscle and brain, but showed statistically significant difference (p < 0.05) in stopping power of adipose (2.4 ± 1.7%) and bony structures such as spongiosa, and cranium (-3.2 ± 1.4 and -3.1 ± 2.1%, respectively). CONCLUSION/CONCLUSIONS:The MVCT calibration might not agree with the corresponding kVCT calibration for some tissues.
PMID: 26924472
ISSN: 1724-191x
CID: 2932062

Thoracic Vertebral Body Irradiation Contributes to Acute Hematologic Toxicity During Chemoradiation Therapy for Non-Small Cell Lung Cancer

Deek, Matthew P; Benenati, Brian; Kim, Sinae; Chen, Ting; Ahmed, Inaya; Zou, Wei; Aisner, Joseph; Jabbour, Salma K
PURPOSE/OBJECTIVE:To determine the relationships between radiation doses to the thoracic bone marrow and declines in blood cell counts in non-small cell lung cancer (NSCLC) patients treated with chemoradiation therapy (CRT). METHODS AND MATERIALS/METHODS:We included 52 patients with NSCLC treated with definitive concurrent carboplatin-paclitaxel and RT. Dose-volume histogram (DVH) parameters for the thoracic vertebrae (TV), sternum, scapulae, clavicles, and ribs were assessed for associations with changes in blood counts during the course of CRT. Linear and logistic regression analyses were performed to identify associations between hematologic nadirs and DVH parameters. A DVH parameter of Vx was the percentage of the total organ volume exceeding x radiation dose. RESULTS:Grade ≥ 3 hematologic toxicity including neutropenia developed in 21% (n=11), leukopenia in 42% (n=22), anemia in 6% (n=3), and throbocytopenia in 2% (n=1) of patients. Greater RT dose to the TV was associated with higher risk of grade ≥ 3 leukopenia across multiple DVH parameters, including TV V20 (TVV) (odds ratio [OR] 1.06; P=.025), TVV30 (OR 1.07; P=.013), and mean vertebral dose (MVD) (OR 1.13; P=.026). On multiple regression analysis, TVV30 (β = -0.004; P=.018) and TVV20 (β = -0.003; P=.048) were associated with white blood cell nadir. Additional bone marrow sites (scapulae, clavicles, and ribs) did not affect hematologic toxicity. A 20% chance of grade ≥ 3 leukopenia was associated with a MVD of 13.5 Gy and a TTV30 of 28%. Cutoff values to avoid grade ≥ 3 leukopenia were MVD ≤ 23.9 Gy, TVV20 ≤ 56.0%, and TVV30 ≤ 52.1%. CONCLUSIONS:Hematologic toxicity is associated with greater RT doses to the TV during CRT for NSCLC. Sparing of the TV using advanced radiation techniques may improve tolerance of CRT and result in improved tolerance of concurrent chemotherapy.
PMCID:5767469
PMID: 26700708
ISSN: 1879-355x
CID: 2932122

Characterization of the effect of MRI on Gafchromic film dosimetry

Reyhan, Meral L; Chen, Ting; Zhang, Miao
Magnetic resonance (MR) imaging of Gafchromic film causes perturbation to absolute dosimetry measurements; the purpose of this work was to characterize the perturbation and develop a correction method for it. Three sets of Gafchromic EBT2 film were compared: radiation (control), radiation followed by MR imaging (RAD + B), and MR imaging followed by radiation (B + RAD). The T1-weighted and T2-weighted MR imaging was performed using a 1.5T scanner with the films wedged between two chicken legs. Doses from 0 to 800 cGy were delivered with a 6MV linac. The time interval between radiation and MR imaging was less than 10 min. Film calibration was generated from the red channel. Microscopic imaging was performed on two pieces of film. The effect of specific absorption rate (SAR) was determined by exposing another three sets of films to low, medium, and high levels of SAR through a series of pulse sequences. No discernible preferential alignment was detected on the microscopic images of the irradiated film exposed to MRI. No imaging artifacts were introduced by Gafchromic film on any MR images. On average, 4% dose difference was observed between B + RAD or RAD + B and the control, using the same calibration curve. The pixel values between the B + RAD or RAD + B and the control films were found to follow a linear relationship pixel(Control) = 1.02 × pixel(B + RAD or RAD + B). By applying this correction, the average dose error was reduced to approximately 2%. The SAR experiment revealed a dose overestimation with increasing SAR even when the correction was applied. It was concluded that MR imaging introduces perturbation on Gafchromic film dose measurements by 4% on average, compared to calibrating the film without the presence of MRI. This perturbation can be corrected by applying a linear correction to the pixel values. Additionally, Gafchromic film did not introduce any imaging artifacts in any of the MR images acquired.
PMCID:5690986
PMID: 26699587
ISSN: 1526-9914
CID: 2932052

Potential of 3D printing technologies for fabrication of electron bolus and proton compensators

Zou, Wei; Fisher, Ted; Zhang, Miao; Kim, Leonard; Chen, Ting; Narra, Venkat; Swann, Beth; Singh, Rachana; Siderit, Richard; Yin, Lingshu; Teo, Boon-Keng Kevin; McKenna, Michael; McDonough, James; Ning, Yue J
In electron and proton radiotherapy, applications of patient-specific electron bolus or proton compensators during radiation treatments are often necessary to accommodate patient body surface irregularities, tissue inhomogeneity, and variations in PTV depths to achieve desired dose distributions. Emerging 3D printing technologies provide alternative fabrication methods for these bolus and compensators. This study investigated the potential of utilizing 3D printing technologies for the fabrication of the electron bolus and proton compensators. Two printing technologies, fused deposition modeling (FDM) and selective laser sintering (SLS), and two printing materials, PLA and polyamide, were investigated. Samples were printed and characterized with CT scan and under electron and proton beams. In addition, a software package was developed to convert electron bolus and proton compensator designs to printable Standard Tessellation Language file format. A phantom scalp electron bolus was printed with FDM technology with PLA material. The HU of the printed electron bolus was 106.5 ± 15.2. A prostate patient proton compensator was printed with SLS technology and polyamide material with -70.1 ± 8.1 HU. The profiles of the electron bolus and proton compensator were compared with the original designs. The average over all the CT slices of the largest Euclidean distance between the design and the fabricated bolus on each CT slice was found to be 0.84 ± 0.45 mm and for the compensator to be 0.40 ± 0.42 mm. It is recommended that the properties of specific 3D printed objects are understood before being applied to radiotherapy treatments.
PMCID:5690113
PMID: 26103473
ISSN: 1526-9914
CID: 2931962

Meshless Deformable Models for 3D Cardiac Motion and Strain Analysis from Tagged MRI

Wang, Xiaoxu; Chen, Ting; Zhang, Shaoting; Schaerer, Joel; Qian, Zhen; Huh, Suejung; Metaxas, Dimitris; Axel, Leon
Tagged Meganetic Resonance Image (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the nessicity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model. Volumetric meshless deformable models describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the tagged MRI with polar decomposition. A 3D meshless deformable model is generated and deformed with MR image tagging lines. Volumetric meshless deformable models are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with Moving Least Squares (MLS). We demonstrate that meshless deformable models outperformed the finite element method (FEM) and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the meshless deformable model can fully recover the myocardium motion in three dimension.
PMCID:4876045
PMID: 25157446
ISSN: 0730-725x
CID: 1162302

The Role of Fibronectin on Spatial Organization in 3D Culture: a Model for Wound Healing after Breast Reconstruction and Post-Mastectomy Radiation Therapy [Meeting Abstract]

Hsia, Henry C; Tian, Sibo; Goyal, Sharad; Haffty, Bruce G; Chen, Ting; Foty, Ramsey A
ORIGINAL:0012465
ISSN: 1529-4242
CID: 2932392

Tagged MRI based cardiac motion modeling and toxicity evaluation in breast cancer radiotherapy

Chen, Ting; Reyhan, Meral; Yue, Ning; Metaxas, Dimitris N; Haffty, Bruce G; Goyal, Sharad
PMCID:4315014
PMID: 25692095
ISSN: 2234-943x
CID: 2932012

The Role of Fibronectin on Spatial Organization in 3D Culture: A Model for Wound Healing After Radiation Therapy [Meeting Abstract]

Tian, S.; Goyal, S.; Haffty, B. G.; Chen, T.; Hsia, H. C.
ISI:000342331403035
ISSN: 0360-3016
CID: 2932312