Search

Two new dihydro- β -agarofuran sesquiterpenoids (1 and 2) together with eight known analogs (3 – 10) were isolated from the roots of Tripterygium regelii. The chemical structures of these isolates were determined by 1D and 2D NMR, HRESIMS, and X-ray crystallography. In addition, all compounds were evaluated for their anti-inflammatory activity using the LPS-induced RAW 264.7 inflammatory cell model. Compounds 1 and 10 inhibited NO production in RAW 264.7 cells by more than 70 % at 100 μM. [Display omitted] • Two new sesquiterpenoids together with eight known analogs were isolated from Tripterygium regelii. • The absolute configuration of compound 1 was determined by X-ray crystallography. • Compounds 1 and 10 inhibited NO production more than 70 % at 100 μM. [ABSTRACT FROM AUTHOR]

We aimed to compare prototype treatment plans for a new biology-guided radiotherapy (BgRT) machine in its intensity-modulated radiation therapy (IMRT) mode with those using existing IMRT delivery techniques in treatment of nasopharyngeal carcinoma (NPC). We retrospectively selected ten previous NPC patients treated in 33 fractions according to the NRG-HN001 treatment protocol. Three treatment plans were generated for each patient: a helical tomotherapy (HT) plan with a 2.5-cm jaw, a volumetric modulated arc therapy (VMAT) plan using 2 to 4 6-MV arc fields, and a prototype IMRT plan for a new BgRT system which uses a 6-MV photon beam on a ring gantry that rotates at 60 rotations per minute with a couch that moves in small incremental steps. Treatment plans were compared using dosimetric parameters to planning target volumes (PTVs) and organs at risk (OARs) as specified by the NRG-HN001 protocol. Plans for the three modalities had comparable dose coverage, mean dose, and dose heterogeneity to the primary PTV, while the prototype IMRT plans had greater dose heterogeneity to the non-primary PTVs, with the average homogeneity index ranging from 1.28 to 1.50 in the prototype plans. Six of all the 7 OAR mean dose parameters were lower with statistical significance in the prototype plans compared to the HT and VMAT plans with the other mean dose parameter being comparable, and all the 18 OAR maximum dose parameters were comparable or lower with statistical significance in the prototype plans. The average left and right parotid mean doses in the prototype plans were 10.5 Gy and 10.4 Gy lower than those in the HT plans, respectively, and were 5.1 Gy and 5.2 Gy lower than those in the VMAT plans, respectively. Compared to that with the HT and VMAT plans, the treatment time was longer with statistical significance with the prototype IMRT plans. Based on dosimetric comparison of ten NPC cases, the prototype IMRT plans achieved comparable or better critical organ sparing compared to the HT and VMAT plans for definitive NPC radiotherapy. However, there was higher dose heterogeneity to non-primary targets and longer estimated treatment time with the prototype plans. [ABSTRACT FROM AUTHOR]

Our purpose was to analyze dose-volume parameters associated with genitourinary (GU) toxicity from a phase I clinical trial of prostate bed stereotactic body radiation therapy. Patients were treated in escalating dose levels of 35, 40, and 45 Gy, over 5 fractions. Data from all 26 patients enrolled in the protocol were analyzed using multiple dose-volume cut points for multiple GU organs at risk. Univariate logistical regression and Fisher exact test were used to assess statistical significance associated with incidence of toxicity. The median follow-up was 36 months for all patients. Acute GU toxicity was mild and resolved spontaneously. Eight out of 26 patients (30.7%) developed late GU toxicity of grade 2 or higher. Two patients developed grade 3 ureteral stenosis, 1 in the 35 Gy arm and the other in the 45 Gy arm. Three patients developed grade 2 or higher hematuria/cystitis, and 3 developed grade 2 or higher incontinence. Incidence of grade 3 ureteral stenosis was related to the absolute volume of bladder wall receiving greater than 20, 25, and 30 Gy (P <.01). Grade 2 cystitis and hematuria were related to the volume of bladder wall receiving 20 Gy less than 34% and 35 Gy less than 25% (18.8% vs 60% and 23.8% vs 80%, respectively, P <.05). Incontinence was related to mean urethral dose less than 35 Gy and 25 Gy (4.3% vs 66.7% and 0% vs 37.5%, respectively, P <.05) and volume of urethra receiving 35 Gy less than 24% (8.3% vs 50%, P <.05). This is the first analysis to report dose-volume thresholds associated with late GU toxicity in patients receiving prostate bed stereotactic body radiation therapy. We recommend limiting the bladder wall receiving 25 Gy to less than 18 cubic centimeters to reduce the risk for late grade 3 ureteral stenosis. [ABSTRACT FROM AUTHOR]

We aimed to predict and compare radiation-induced, organ-specific, secondary solid-tumor occurrence risks from conventional total body irradiation (TBI) and total marrow irradiation (TMI) for patients undergoing hematopoietic cell transplant. We retrospectively selected 20 patients who received TMI treatments before hematopoietic cell transplant. Ten patients (5 men; 5 women) received 12 Gy to the skeletal bones, lymph nodes, and spleen, and the other 10 patients (5 men; 5 women) received an escalated dose of 20 Gy to the same targets and 12 Gy to the brain and liver. A conventional TBI treatment plan was generated for each patient with a prescription dose of 12 Gy, using anterior-posterior and posterior-anterior photon beams with lung shielding and a chest wall boost with electron beams. Secondary cancer risks were estimated using linear-exponential and plateau models for major organs. At the 12 Gy dose level, using the linear-exponential model, the total radiation-induced secondary solid-tumor risks for major organs were 159.3 ± 8.7 for men and 221.5 ± 14.4 for women per 10,000 people per year with the TMI plans, which is a reduction of 38.8% and 32.9%, respectively, compared with those with the TBI plans. At the 20 Gy dose level, the risks were 220.3 ± 8.3 for men and 298.5 ± 9.3 for women with the TMI plans, which is a reduction of 14.6% and 9.2%, respectively, compared with those with the 12 Gy TBI plans. Significant risk reductions were also found with the TMI plans using the plateau risk model. At both the 12 Gy and 20 Gy prescription dose levels, a conditioning regimen using TMI could significantly lower overall radiation-induced secondary solid-tumor risks for major organs compared with a conditioning regimen with standard 12 Gy TBI. Clinical data from long-term follow-up studies are needed to verify the model predictions. [ABSTRACT FROM AUTHOR]

• The self-healing of SMA-ECC under compression was studied. • Ultrasonic pulse testing explains SMA-ECC self-healing efficiency. • Mechanical properties and damage resistance of SMA-ECC after pre-damage. • Recommend SMA fiber content range based on experiment indicators. A two-stage compressive test was adopted to study the self-healing performance of a smart cementitious composite SMA-ECC under compression. The ultrasonic pulse and sorptivity tests were used to track self-healing ability and resistance to internal damage, respectively. A total of 32 groups of specimens, including 28 groups of SMA-ECC specimens and 4 groups of ordinary ECC specimens, were tested with various fiber contents and preloading levels. The strength recovery rate, relative dynamic elastic modulus recovery rate before and after self-healing, and cumulative water absorption were measured during the tests. It was found that the strength recovery rate of the SMA-ECC increased by 29.2% to 37.2% compared to the ordinary ECC. The elastic modulus recovery rate after self-healing of the SMA-ECC is approximately 3 to 10 times that of the ordinary ECC, and SMA-ECC with a 0.9% fiber content exhibits the best healing effect, with a remarkable 194% increase in elastic modulus recovery rate compared to ECC. As for internal damage, an increase in fiber content corresponds to a decrease in relative sorptivity coefficient (η) in most cases. Notably, for SMA-ECC specimens featuring a 0.9% fiber content, η reaches its nadir, hovering around 0.7. The situation takes an unexpected turn when fiber content hits 1%, as the relative sorptivity coefficient experiences a 14.9% increment compared to the SMA-ECC with 0.9% fiber content. Based on the test results, it is concluded that the SMA-ECC has excellent compressive recovery performance and the ability to resist internal damage. The optimal SMA fiber content for the self-healing performance of the SMA-ECC is determined to be 0.7% to 0.9%. [ABSTRACT FROM AUTHOR]

Adsorption with granules is critical for lithium recovery from brines due to the simplicity, efficiency, and environmental-friendliness of its industrial process. However, obtaining hydrophilic and stable binders remains to be a challenging task. Herein, a one-pot green strategy for granulating Li 1.33 Mn 1.67 O 4 (LMO-1) powder into PVA/LMO-1 composites was developed with hydrophilic poly(vinyl alcohol) (PVA) as a binder and glycidoxypropyltrimethoxysilane (GPTES) as a coupling agent. Hydrogen peroxide (H 2 O 2) was added to the reaction process to create pores by its thermal decomposition. The powder in the coupling composites would be difficult to leach out when compared to the granulation method of physical blending. Furthermore, the resulting PVA/LMO-1 demonstrated high water absorbency, pH stability, and fast water/ion exchange without visible swelling, which are important in industrial scale-up experiments where energy consumption and time can be reduced. Additionally, the selectivity of different ions of granulated PVA/LMO-1 was evaluated and confirmed. The lithium adsorption efficiency in real brine (produced water from the Puguang gas field) was 93.5%, which is higher than that of other adsorbents with comparable adsorption capacity; Meanwhile the magnesium-lithium ratios (Mg2+/Li+ ratios) decreased from 8.92 to 0.15, Na+/Li+ ratios decreased from 997 to 1.35, K+/Li+ ratios decreased from 30.26 to 0.29, Ca2+/Li+ from 30.87 to 2.36, indicating that the high salt content and organic pollutants of real bine do not affect the performance of the adsorbent. Long-term cyclic results showed that the structure and adsorption capacity of PVA/LMO-1 were stable. All these properties demonstrate that the developed PVA/LMO-1 absorbent could provide an appealing and competitive method for the industrial process. [ABSTRACT FROM AUTHOR]

We aimed to compare gross tumor volumes (GTV) in 3-dimensional computed tomography (3DCT) simulation and daily cone beam CT (CBCT) with the internal target volume (ITV) in 4-dimensional CT (4DCT) simulation in stereotactic body radiotherapy (SBRT) treatment of patients with early-stage non–small cell lung cancer (NSCLC) under abdominal compression. We retrospectively selected 10 patients with NSCLC who received image-guided SBRT treatments under abdominal compression with daily CBCT imaging. GTVs were contoured as visible gross tumor on the planning 3DCT and daily CBCT, and ITVs were contoured using maximum intensity projection (MIP) images of the planning 4DCT. Daily CBCTs were registered with 3DCT and MIP images by matching of bony landmarks in the thoracic region to evaluate interfractional GTV position variations. Relative to MIP-based ITVs, the average 3DCT-based GTV volume was 66.3 ± 17.1% (range: 37.5% to 92.0%) ( p  < 0.01 in paired t-test), and the average CBCT-based GTV volume was 90.0 ± 6.7% (daily range: 75.7% to 107.1%) ( p  = 0.02). Based on bony anatomy matching, the center-of-mass coordinates for CBCT-based GTVs had maximum absolute shift of 2.4 mm (left-right), 7.0 mm (anterior-posterior [AP]), and 5.2 mm (superior-inferior [SI]) relative to the MIP-based ITV. CBCT-based GTVs had average overlapping ratio of 81.3 ± 11.2% (range: 45.1% to 98.9%) with the MIP-based ITV, and 57.7 ± 13.7% (range: 35.1% to 83.2%) with the 3DCT-based GTV. Even with abdominal compression, both 3DCT simulations and daily CBCT scans significantly underestimated the full range of tumor motion. In daily image-guided patient setup corrections, automatic bony anatomy-based image registration could lead to target misalignment. Soft tissue-based image registration should be performed for accurate treatment delivery. [ABSTRACT FROM AUTHOR]

Abstract: Interpersonal curiosity (IPC) is an important intrinsic motivation in social interaction, yet studies focused on its neural mechanism are rare. In a three-agent (Self, Other, or Computer) interactive gambling task, we recorded event-related potentials (ERPs) to a cue stimuli indicating whether participants will be informed of their own, of another participant''s or the computer''s outcomes such that curiosity will be satisfied (CWS) or curiosity will not be satisfied (CWN). The results showed that relative to the CWS cue stimuli the CWN cue evoked a larger late positive component (LPC) between approximately 400ms and 700ms after cue onset in both the Self and Other conditions, but not in the Computer condition. Additionally, participants reported stronger curiosity in the Other''s outcomes than in the Computer''s outcomes. Most importantly, participants’ subjective rating of curiosity was significantly correlated with the amplitude of the LPC elicited by the CWN cue. Furthermore, scores in the “curiosity about emotion” subscale of the IPC Scale was significantly correlated with the LPC amplitude when the participants learn they will not be informed of the Other''s outcomes. We suggest that (1) interpersonal information is of great significance to individuals and IPC is an important social motivator, and (2) LPC amplitude is sensitive toIPC. [Copyright &y& Elsevier]

Abstract: Background and purpose: To evaluate residual patient setup errors and daily dose variations of different less-than-daily image guidance (IG) strategies in the delivery of external beam radiotherapy for esophageal cancer. Material and methods: Daily image-guided setup data for 25 consecutive esophageal cancer patients treated with helical tomotherapy were evaluated. Seven less-than-daily IG strategies with different imaging frequencies were simulated. For each IG strategy, the daily residual setup errors were calculated. Using TomoTherapy Planned Adaptive software, daily dose variations to the clinical target volume, heart, and lungs were evaluated in five representative patients. Results: With 0% (60%) IG frequency, the margins required for adequate coverage of the clinical target volume were 13mm (10mm), 14mm (11mm), and 5mm (5mm) in the left–right, superior–inferior, and anterior–posterior directions, respectively. Even with 60% IG frequency, 10% of the fractions had more than 10% decrease in the dose level covering 95% of the target, and 14% and 13% of the fractions had more than 10% increase in total lung volume receiving at least 0.8Gy per fraction, and heart volume receiving at least 1.2Gy per fraction, respectively. Conclusion: Substantial residual setup errors would occur for treatment fractions without IG even if the most frequent less-than-daily IG strategy was to be used, which could lead to significant daily dose variations for the target volume and adjacent normal tissues. Daily image guidance is recommended throughout the course of treatment in conformal radiotherapy for esophageal cancer. [Copyright &y& Elsevier]

Abstract: Background and purpose: Normal organ toxicity is the leading factor that limits dose escalation in total body irradiation for bone marrow transplant (BMT) patients. In recent years, total marrow irradiation (TMI) using the helical tomotherapy (HT) system is being used as a more targeted form of TBI to treat BMT patients. In this study, we evaluated the feasibility of using volumetric modulated arc therapy (VMAT) to deliver TMI treatment. Materials and methods: CT data sets from two female and two male patients who had received prior total marrow and lymphatic irradiation with HT were selected for this study. The target volumes included skeletal bones from the skull to the mid-thigh level, major lymph nodes, and spleen. Twelve Gray in 8 fractions was prescribed to the target volumes. Each VMAT plan was generated with eight arc fields to cover the entire target volumes. Both the VMAT and the HT plans were normalized so that 85% of the skeletal bone volume was covered by the prescription dose. For each patient, more than 20 normal organs were included in plan optimization. Results: Both the VMAT and HT plans showed comparable dose coverage to the target volumes and significant sparing of normal organ dose. The median dose to the skeletal bone volume was 13.4 and 12.6Gy in the VMAT and HT plans, respectively. The VMAT plans showed >10% and >20% reduction of average median dose compared to the HT plans in 16 and 11 organs, respectively. The average beam-on time was 628±32s and 1122±106s in the VMAT and HT plans, respectively. Conclusions: The VMAT plans provided adequate target dose coverage and normal organ sparing compared to helical tomotherapy plans for efficient delivery of total marrow and lymphatic irradiation. This study demonstrates that the VMAT technique could be a feasible alternative to helical tomotherapy for TMI treatment. [Copyright &y& Elsevier]

Purpose: For intensity-modulated radiotherapy of nasopharyngeal cancer, accurate dose delivery is crucial to the success of treatment. This study aimed to evaluate the significance of daily image-guided patient setup corrections and to quantify the parotid gland volume and dose variations for nasopharyngeal cancer patients using helical tomotherapy megavoltage computed tomography (CT). Methods and Materials: Five nasopharyngeal cancer patients who underwent helical tomotherapy were selected retrospectively. Each patient had received 70 Gy in 35 fractions. Daily megavoltage CT scans were registered with the planning CT images to correct the patient setup errors. Contours of the spinal cord and parotid glands were drawn on the megavoltage CT images at fixed treatment intervals. The actual doses delivered to the critical structures were calculated using the helical tomotherapy Planned Adaptive application. Results: The maximal dose to the spinal cord showed a significant increase and greater variation without daily setup corrections. The significant decrease in the parotid gland volume led to a greater median dose in the later phase of treatment. The average parotid gland volume had decreased from 20.5 to 13.2 cm3 by the end of treatment. On average, the median dose to the parotid glands was 83 cGy and 145 cGy for the first and the last treatment fractions, respectively. Conclusions: Daily image-guided setup corrections can eliminate significant dose variations to critical structures. Constant monitoring of patient anatomic changes and selective replanning should be used during radiotherapy to avoid critical structure complications. [Copyright &y& Elsevier]

Purpose: To use pretreatment megavoltage computed tomography (MVCT) scans to evaluate setup variations in anterior-posterior (AP), lateral, and superior-inferior (SI) directions and rotational variations, including pitch, roll, and yaw, for esophageal cancer patients treated with helical tomotherapy. Methods and Materials: Ten patients with locally advanced esophageal cancer treated by combined chemoradiation using helical tomotherapy were selected. After patients were positioned using their skin tattoos/marks, MVCT scans were performed before every treatment and automatically registered to planning kilovoltage CT scans according to bony landmarks. Image registration data were used to adjust patient setups before treatment. A total of 250 MVCT scans were analyzed. Correlations between setup variations and body habitus, including height, weight, relative weight change, body surface area, and patient age, were evaluated. Results: The standard deviations for systematic setup corrections in AP, lateral, and SI directions and pitch, roll, and yaw rotations were 1.5, 3.7, and 4.8 mm and 0.5 degrees, 1.2 degrees, and 0.8 degrees, respectively. The appropriate averages of random setup variations in AP, lateral, and SI directions and pitch, roll, and yaw rotations were 2.9, 5.2, and 4.4 mm, and 1.0 degrees, 1.2 degrees, and 1.1 degrees, respectively. Setup variations were stable throughout the entire course of radiotherapy in all three translational and three rotational displacements, with little change in magnitude. No significant correlations were found between setup variations and body habitus variables. Conclusions: Daily MVCT scans before each treatment can effectively detect setup errors and thereby reduce planning target volume (PTV) margins. This will reduce radiation dose to critical organs and may translate into lower treatment-related toxicities. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluated the efficacy of using helical tomotherapy for conformal avoidance treatment of anal adenocarcinoma. We retrospectively generated step-and-shoot intensity-modulated radiotherapy (sIMRT) plans and helical tomotherapy plans for two anal cancer patients, one male and one female, who were treated by the sIMRT technique. Dose parameters for the planning target volume (PTV) and the organs-at-risk (OARs) were compared between the sIMRT and the helical tomotherapy plans. The helical tomotherapy plans showed better dose homogeneity in the PTV, better dose conformity around the PTV, and, therefore, better sparing of nearby OARs compared with the sIMRT plans. In-vivo skin dose measurements were performed during conformal avoidance helical tomotherapy treatment of an anal cancer patient to verify adequate delivery of skin dose and sparing of OARs. [Copyright &y& Elsevier]

Purpose: To evaluate dose conformity, dose homogeneity, and dose gradient in helical tomotherapy treatment plans for stereotactic radiosurgery, and compare results with step-and-shoot intensity-modulated radiosurgery (IMRS) treatment plans. Methods and Materials: Sixteen patients were selected with a mean tumor size of 14.65 +/- 11.2 cm3. Original step-and-shoot IMRS treatment plans used coplanar fields because of the constraint of the beam stopper. Retrospective step-and-shoot IMRS plans were generated using noncoplanar fields. Helical tomotherapy treatment plans were generated using the tomotherapy planning station. Dose conformity index, dose gradient score index, and homogeneity index were used in plan intercomparisons. Results: Noncoplanar IMRS plans increased dose conformity and dose gradient, but not dose homogeneity, compared with coplanar IMRS plans. Tomotherapy plans increased dose conformity and dose gradient, yet increased dose heterogeneity compared with noncoplanar IMRS plans. The average dose conformity index values were 1.53 +/- 0.38, 1.35 +/- 0.15, and 1.26 +/- 0.10 in coplanar IMRS, noncoplanar IMRS, and tomotherapy plans, respectively. The average dose homogeneity index values were 1.15 +/- 0.05, 1.13 +/- 0.04, and 1.18 +/- 0.09 in coplanar IMRS, noncoplanar IMRS, and tomotherapy plans, respectively. The mean dose gradient score index values were 1.37 +/- 19.08, 22.32 +/- 19.20, and 43.28 +/- 13.78 in coplanar IMRS, noncoplanar IMRS, and tomotherapy plans, respectively. The mean treatment time in tomotherapy was 42 +/- 16 min. Conclusions: We were able to achieve better dose conformity and dose gradient in tomotherapy plans compared with step-and-shoot IMRS plans for intracranial stereotactic radiosurgery. However, tomotherapy treatment time was significantly larger than that in step-and-shoot IMRS. [ABSTRACT FROM AUTHOR]

Purpose In this study, we evaluated radiation-induced secondary lung cancer risks for the lung and the breast from stereotactic body radiation therapy treatment of early-stage non–small cell lung cancer with different radiation therapy treatment modalities. Methods and materials Ten patients (5 men and 5 women) with early-stage non–small cell lung cancer who received definitive stereotactic body radiation therapy treatments were retrospectively selected. For each patient, two 3-dimensional conformal radiation therapy (3D-CRT) plans using 6- and 10-MV photons, respectively; a helical tomotherapy (HT) plan; and 2 volumetric modulated arc therapy (VMAT) plans using 1 and 2 arcs, respectively, were generated. The excess absolute risk (EAR) for secondary cancer occurrence was calculated using 3 organ equivalent dose models: the linear-exponential model, the plateau model, and the linear model for prescription dose range of 30 to 70 Gy. Results The 3D-CRT plans showed significantly lower monitor units compared with the rotational intensity modulate radiation therapy plans. Based on each of the 3 organ equivalent dose models, HT and VMAT plans showed comparable average EARs to both the lung and the breast compared with the 3D-CRT plans in the prescription dose range of 30 to 70 Gy. At a prescription dose of 50 Gy and using the linear-exponential model, the average lung EAR estimation ranged from 15.7 ± 5.3 to 16.0 ± 6.5 per 10,000 patients per year with the 5 delivery techniques, and the average EAR estimation for the breast ranged from 18.0 ± 14.0 to 21.0 ± 15.0 per 10,000 patients per year. The secondary cancer risk increased approximately linearly with mean organ dose. The 3D-CRT plans showed significantly higher secondary cancer risk for the ipsilateral lung and lower risk for the contralateral lung compared with the HT and VMAT plans. Conclusions Rotational intensity modulate radiation therapy techniques including helical tomotherapy and VMAT do not increase secondary cancer risks for the lung or the breast compared with 3D-CRT techniques, despite higher monitor units used. [ABSTRACT FROM AUTHOR]

Geometric and nomenclature errors are commonly encountered in automated treatment planning. We describe a novel algorithm to extract organ geometry relationships from patient structure DICOM data to construct a database that can be used to detect organ contour inaccuracies including relational and naming errors. Twenty-five sets of head and neck patients' treatment plan data (CT, structures) were retrospectively retrieved from our institution. For each dataset, various organs were contoured and verified by experienced physicians. The relative position and orientation between organs were extracted from each patient and the data were used to construct an organ relationship database model. The model was tested using a dataset originating from an in-house organ renaming software that often-introduced organ contour naming mismatches. As part of the validation test, the renamed organs relative positions were compared with the database model to identify mismatches. Within the forty head and neck patients, we extracted the geometric relationship between 201 organ pairs. The average number of unique types of organ pairs (for example, left parotid with left eye is one type of organ pair) stored in the database was 12. Fifteen head and neck structure sets automatically renamed using our in-house organ renaming tool was used as validation data. All of the 30 random assigned wrong name labels present in these structure sets were identified using the established organ geometry relationship database. We successfully constructed a head and neck organ geometry relationship database and validated it in a contour naming quality assurance process. This novel scheme can be expanded to the entire body and shows a great potential in automatic plan physics QA procedure. It should be one essential QA step in an autonomous treatment planning process. [ABSTRACT FROM AUTHOR]

Abstract: We compare different radiotherapy techniques—helical tomotherapy (tomotherapy), step-and-shoot IMRT (IMRT), and 3-dimensional conformal radiotherapy (3DCRT)—for patients with mid-distal esophageal carcinoma on the basis of dosimetric analysis. Six patients with locally advanced mid-distal esophageal carcinoma were treated with neoadjuvant chemoradiation followed by surgery. Radiotherapy included 50 Gy to gross planning target volume (PTV) and 45 Gy to elective PTV in 25 fractions. Tomotherapy, IMRT, and 3DCRT plans were generated. Dose-volume histograms (DVHs), homogeneity index (HI), volumes of lung receiving more than 10, 15, or 20 Gy (V10, V15, V20), and volumes of heart receiving more than 30 or 45 Gy (V30, V45) were determined. Statistical analysis was performed by paired t-tests. By isodose distributions and DVHs, tomotherapy plans showed sharper dose gradients, more conformal coverage, and better HI for both gross and elective PTVs compared with IMRT or 3DCRT plans. Mean V20 of lung was significantly reduced in tomotherapy plans. However, tomotherapy and IMRT plans resulted in larger V10 of lung compared to 3DCRT plans. The heart was significantly spared in tomotherapy and IMRT plans compared to 3DCRT plans in terms of V30 and V45. We conclude that tomotherapy plans are superior in terms of target conformity, dose homogeneity, and V20 of lung. [Copyright &y& Elsevier]

Abstract: Purpose: To compare step-and-shoot intensity-modulated radiation therapy (SAS-IMRT) and helical tomotherapy (Tomo) dosimetry plans for patients who have received adjuvant radiation therapy for retroperitoneal sarcomas (RSTS). Methods and Materials: A retrospective review was performed for seven patients who received either SAS-IMRT or Tomo as adjuvant radiation therapy for RSTS. In each case, a treatment plan of the other modality was generated so that SAS-IMRT and Tomo could be compared. Results: The average percentage of clinical target volume (CTV) that received less than the prescription dose was 1.4% for Tomo compared to 3.8% for SAS-IMRT. Both SAS-IMRT and Tomo plans provided comparable and significant reductions in volume of small bowel receiving greater than 45Gy compared to simple opposing standard radiation fields. For the ipsilateral kidney, Tomo significantly reduced the volume of kidney that received at least 15Gy (average 22% for Tomo vs. 56% for SAS-IMRT). Conclusion: Both SAS-IMRT and Tomo can encompass the large CTV often required for patients with RSTS, although Tomo provides superior dose uniformity. Both SAS-IMRT and Tomo can minimize the volume of small bowel receiving greater than 45Gy. Tomo was superior to SAS-IMRT in minimizing the volume of ipsilateral kidney irradiated to greater than 15Gy when the CTV is adjacent to a kidney. Dose escalation and target margin expansion may thus become realistic possibilities. [Copyright &y& Elsevier]

Purpose: Toxicities after organ sparing myeloablative total marrow irradiation (TMI) conditioning regimens have not been well characterized. The purpose of this study is to report pulmonary, renal, thyroid, and cataract toxicities from a prospective trial monitoring patients up to 8 years after TMI.Methods and Materials: A total of 142 patients with primarily multiple myeloma or acute leukemia undergoing hematopoietic cell transplantation were evaluated. Follow-up included pulmonary function tests, serum creatinine, glomerular filtration rate, thyroid panel, and ophthalmologic examinations performed at 100 days, 6 months, and annually. Median TMI dose was 14 Gy (10-19 Gy) delivered at 1.5 to 2.0 Gy twice per day at a dose-rate of 200 cGy/min.Results: Median age was 52 years (range 9-70). Median follow-up (range) for all patients was 2 years (0-8) and for patients alive at the time of last follow-up (n = 50), 5.5 years (0-8). Mean organ doses in Gy were lung 7.0, kidneys 7.1, thyroid 6.7, and lens 2.8. The crude incidence of radiation pneumonitis (RP) was 1 of 142 (0.7%). The cumulative incidence of infection and RP (I/RP) was 22.7% at 2 years post-TMI. Mean lung dose ≤8 Gy predicted for significantly lower rates of I/RP (2-year cumulative incidence 20.8% vs 31.8%, P = .012). No radiation-induced renal toxicity was noted. Hypothyroidism occurred in 6.0% and cataract formation in 7.0% of patients.Conclusions: TMI delivered with intensity modulated radiation therapy results in lower organ doses and was associated with fewer toxicities compared with historical cohorts treated with conventional total body irradiation. Keeping the mean lung dose to 8 Gy or less was associated with lower pulmonary complications. Further evaluation in clinical trials of intensity modulated radiation therapy to deliver TMI, total marrow and lymphoid irradiation, and organ sparing conformal total body irradiation is warranted. [ABSTRACT FROM AUTHOR]

The mismatch of spatial distribution between water resources and human activities presents a considerable challenge to the sustainable utilization of water resources. This trend is further exacerbated by the impact of climate change and the increasingly frequent occurrence of extreme weather. Therefore, it is imperative to conduct an in-depth study on water resource spatial equilibrium (WRSE). This paper proposed an integrated diagnostic framework for WRSE considering the water-economy-ecology nexus, in which an improved evaluation index system of WRSE was constructed. The WRSE states of three criteria layers are quantified with the spatial equilibrium indices of water resource endowment, economic and social development, and ecological environment protection. The water resource spatial equilibrium index (WRSEI) was calculated using the Euclidean distance to reflect the overall spatial equilibrium state. The key influencing factors of WRSE are analyzed through the obstacle degree model. The findings indicate that: a) the WRSEI in the Yangtze River to Huaihe River Water Transfer Project (YHWTP) area showed a gradual increase from 0.641 in 2011 to 0.662 in 2020; b) the WRSE level of each criterion layer attained a general equilibrium or fair equilibrium state, and the WRSE state shows a trend from dispersion to aggregation during 2011 and 2020; c) per capita water resources, per capita gross domestic product and per capita urban wastewater discharge are the main factors limiting the realization of a benign WRSE in the YHWTP, with the obstacle degrees reaching 0.347, 0.324 and 0.326 in 2020 respectively. This framework can provide a theoretical reference for the study of WRSE, and provide a scientific basis and suggestions for policymakers to enhance WRSE and achieve sustainable utilization of water resources. [Display omitted] • A diagnostic framework for water resources spatial equilibrium (WRSE) was developed. • The evaluation index system and quantitative method were improved in terms of WEE nexus. • A state discrimination method of WRSE was proposed to identify the overall WRSE state. • The framework was applied to Yangtze River to Huaihe River Water Transfer Project area. • Findings can help formulate water resources planning and sustainable development strategies. [ABSTRACT FROM AUTHOR]

Purpose: To use pretreatment megavoltage-computed tomography (MVCT) scans to evaluate positioning variations in pitch, roll, and yaw for patients treated with helical tomotherapy. Methods and Materials: Twenty prostate and 15 head-and-neck cancer patients were selected. Pretreatment MVCT scans were performed before every treatment fraction and automatically registered to planning kilovoltage CT (KVCT) scans by bony landmarks. Image registration data were used to adjust patient setups before treatment. Corrections for pitch, roll, and yaw were recorded after bone registration, and data from fractions 1–5 and 16–20 were used to analyze mean rotational corrections. Results: For prostate patients, the means and standard deviations (in degrees) for pitch, roll, and yaw corrections were −0.60 ± 1.42, 0.66 ± 1.22, and −0.33 ± 0.83. In head-and-neck patients, the means and standard deviations (in degrees) were −0.24 ± 1.19, −0.12 ± 1.53, and 0.25 ± 1.42 for pitch, roll, and yaw, respectively. No significant difference in rotational variations was observed between Weeks 1 and 4 of treatment. Head-and-neck patients had significantly smaller pitch variation, but significantly larger yaw variation, than prostate patients. No difference was found in roll corrections between the two groups. Overall, 96.6% of the rotational corrections were less than 4°. Conclusions: The initial rotational setup errors for prostate and head-and-neck patients were all small in magnitude, statistically significant, but did not vary considerably during the course of radiotherapy. The data are relevant to couch hardware design for correcting rotational setup variations. There should be no theoretical difference between these data and data collected using cone beam KVCT on conventional linacs. [Copyright &y& Elsevier]