[Feasibility of a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection for middle and low rectal cancer].

Objective: To explore the feasibility and value of performing a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection (LLND) for middle and low rectal cancer. Methods: This was a retrospective review. The study cohort comprised patients who met the diagnostic criteria for rectal cancer according to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer, had a short lymph node diameter of >5 mm on the lateral side within the 15 days before surgery, were evaluated as feasible candidates for laparoscopic total mesorectal excision+LLND surgery, had been diagnosed with low or intermediate level rectal cancer, and whose tumor was less than 8 cm away from the anal verge according to pathological examination of the operative specimen. Patients with a history of other malignant tumors of the abdomen or with incomplete follow-up data were excluded. Forty-two patients with middle and low rectal cancer who had undergone lateral lymph node dissection in diagnosis and treatment center of Gastrointestinal Cancer of Guangdong Hospital of Chinese Medicine from Jan.2018 to Dec.2022 were enrolled. There were 24 men (57.1%) and 18 women (42.9%) aged 58.4±11.8 years and the median BMI was 22.5 (19.3-24.1) kg/m2. The main point of the three-sided encapsulation procedure is to expand the external side medial to the external iliac artery and vein, narrowing the range of exterior side dissection. The anterior-medial side is designed to expand the vesical fascia to define the range of anterior-medial side extension. The internal side is fully extended to the ureterohypogastric nerve fascia; the distal point of the caudal extension reaches the level of the Alcock canal and the bottom reaches the piriformis, enabling dissection of the obturator nerve and No.283 lymph nodes. No.263D lymph nodes are dissected by exposing the internal iliac artery and its branches, dissecting the group No.263P lymph nodes, and severing the inferior vesical artery. Finally, the lateral lymphatic tissue is completely resected. Relevant variables were recorded, including the number of lateral lymph nodes detected, the rate of lymph node metastasis, operation duration, intraoperative blood loss, postoperative complications, postoperative hospital stay, and 3-year overall survival rate. Results: Laparoscopic surgery was successfully completed in all patients with no conversions to open surgery and no intraoperative complications. Twenty-seven (64.3%) of the study patients underwent left-sided LLND, 10 (23.8%) right-sided LLND, and five (11.9%) bilateral LLND, with lymph nodes cleared on both sides. All patients' lymph nodes were examined pathologically. A median of 17.0 (11.7, 26.0) lymph nodes was detected, the median of lateral lymph nodes being 5.0 (2.0, 10.2). The median operation time was 254.5 (199.0, 325.2) minutes. The median intra-operative blood loss was 50.0 (30.0, 100.0) mL. All patients were diagnosed with adenocarcinoma by pathological examination of the operative specimen. Two patients developed postoperative intestinal obstruction, one lymphatic leakage, and one a perineal incision infection. There were no cases of anastomotic leakage. The median postoperative hospital stay was 6.0 (5.0, 7.0) days and the median follow-up time 23.5 (9.0, 36.7) months. During follow-up, three patients (7.1%) died of tumor recurrence and metastasis. Two (4.8%) experienced mild urinary dysfunction, and one (2.4%) had moderate postoperative erectile dysfunction. One patient (2.4%) was found to have prostate and lung metastases 3 month after surgery. The 3-year overall survival rate was 74.4%. Conclusions: Three sided encapsulation is a safe and feasible procedure for LLND, achieving accurate and complete clearance of lateral lymphatic tissue.

[Key gene leading to poor prognosis of triple-negative breast cancer based on bioinformatics analysis].

Objective: To find the possible targets for the study and treatment of triple-negative breast cancer (TNBC), and to analyze and predict the key genes affecting the prognosis of TNBC by bioinformatics. Methods: Raw data on transcriptome sequencing of clinical specimens from patients with TNBC were searched by searching GEO Datasets in the National Center for Biotechnology Information (NCBI) database. The differential gene was then submitted to the Enrichr website for pathway enrichment. Survival analysis was used to finally identify the most significant differences in the prognosis of patients with TNBC. Results: Only ADAM9 gene showed a significant correlation with the poor prognosis of patients with TNBC (P<0.05), and ADAM9 only showed specificity associated with prognosis in patients with TNBC, and was not with other breast cancer types. Conclusion: ADAM9 gene has been proved to be related to the poor prognosis in patients with TNBC. Therefore, ADAM9 gene can be regarded as a possible key gene leading to lymph node metastasis and poor prognosis in patients with TNBC.

Role of lncRNA-ENST00000412010 in regulating nasopharyngeal cancer cell survival.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a rare tumor with highly recurrent and lack of effective treatment. Long non- coding RNAs (lncRNAs) have been reported to play roles in various cancers including NPC. METHODS: In the current study, two cell lines of NPC (CNE-2Z and 5-8F cells) were transfected with short hairpin RNA (shRNA) targeting lncRNA-ENST00000412010 (shlncRNA) or control shRNA (shControl). Cell proliferation, survival, in vitro colony formation, and in vivo xenograft tumor formation were then investigated. RESULTS: The study found that cells transfected with shlncRNA grew significantly slower than the cells transfected with shControl as measured on day 5; increased in Annexin V expression; decreased in colony formation; and smaller in xenograft tumor size on day 45. Expression of DNA damage-inducible transcript 3, dual specificity protein phosphatase 5, insulin receptor substrate 1, interleukin-6, and tribbles homolog 3 genes was significantly up-regulated in the cells transfected with shlncRNA, while gene expression of matrix metalloproteinase-7 and cyclin-dependent kinase 4 inhibitor B was significantly down-regulated in the cells transfected with shlncRNA. Immunoblotting assay confirmed DUSP5 protein was significantly increased while proteins of MMP-7 and CDKN2B were significantly lower in the cells lacking lncRNA than that of the control cells. CONCLUSIONS: These findings suggested that lncRNA-ENST00000412010 plays a role in modulating NPC survival and tumorigenesis through regulating molecules associated with cell cycle and protein phosphatase.

Long noncoding RNA GAS5 enhanced by curcumin relieves poststroke depression by targeting miR-10b/BDNF in rats.

The treatment for post-stroke depression (PSD) is mainly based on a therapeutic strategy combining anti-stroke and anti-depressant drugs. In the present study, the therapeutic effect of curcumin on rats with PSD was detected by open field tests and tail suspension tests, as well as the examination of corticosterone and corticotropin-releasing hormone (CRH) levels in the serum and neurotransmitter 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and dopamine (DA) levels in the hippocampus. Curcumin notably alleviated depression compared to the controls. Furthermore, long noncoding RNA growth arrest-specific transcript 5 (GAS5) enhanced by curcumin contributed to activation of the BDNF/Trkß signaling pathway to promote the expression of synaptic-related proteins. GAS5 was demonstrated to function as a sponge of miR-10b. GAS5 upregulation by curcumin could reduce miR-10b to compromise the BDNF mRNA levels. Taken together, these results revealed a novel mechanism of curcumin on PSD through the GAS5/miR-10b/BDNF regulatory axis.

Study on molecular mechanism of MiRNA-29a in promoting proliferation and invasion of non-small-cell lung cancer by inhibiting MTSS1.

OBJECTIVE: To investigate the biological role of micro-ribonucleic acid (miR)-29a in non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: 55 cases of NSCLC tissue specimens and paired normal lung tissue specimens collected in the Department II of Oncology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine from July 2012 to April 2015 were randomly included. The fluorescent quantitative polymerase chain reaction, Western blotting, and immunohistochemistry were performed to detect the expression levels of miR-29a and metastasis suppressor 1 (MTSS1). Pearson correlation analysis was utilized to investigate the relationship between miR-29a expression and MTSS1 expression in NSCLC tissues, and the Kaplan-Meier survival curves were constructed to analyze the association of miR-29a expression with the survival time of NSCLC patients. A54 proliferation and invasion abilities were measured by means of plate clone formation assay, and transwell assay after the miR-29a was suppressed by miRNA inhibitor. Luciferase assay was used to detect the target gene of miR-29a. RESULTS: In NSCLC tissues, the miR-29a expression level was higher than that in normal lung tissues (p<0.05), while the expression level of MTSS1 protein was remarkably lower than that in normal lung tissues (p<0.05). The median survival time of the patients was 15.1 months in high miR-29a expression group and 18.3 months in low miR-29a expression group (p<0.05). The miR-29a expression was negatively correlated with the expression level of MTSS1 protein in NSCLC tissues (r=-0.762, p<0.05). Luciferase results suggest that miR-29a binds to the promoter region of MTSS1 and inhibits its transcription level. The expression of MTSS1 protein was up-regulated notably after miR-29a knockdown by an inhibitor. It was revealed in the results of transwell assay and plate clone formation assay that the proliferative and invasive capacity of A549 cells was significantly decreased after knockdown of miR-29a. CONCLUSIONS: The transcribed miR-29a down-regulates the protein level of MTSS1, suppressor of tumor proliferation and invasion, thereby promoting the proliferative and invasive capacity of NSCLC cells. Both miR-29a and MTSS1 are expected to become potential therapeutic targets for NSCLC.

Positive Association Between Betatrophin and Diabetic Retinopathy Risk in Type 2 Diabetes Patients.

Betatrophin is a recently identified protein that has been shown to be associated with lipid metabolism and insulin resistance. This study aimed to measure serum betatrophin concentrations in patients with type 2 diabetes (T2DM) and evaluate the association of betatrophin with diabetic retinopthy (DR). Serum betatrophin concentrations were compared between (1) gender-, age- and body mass index-matched T2DM patients with (n=17) or without (n=33) DR; (2) gender-, age-, and body mass index-matched healthy subjects (n=31), newly-diagnosed T2DM patients before treatment (n=24), and T2DM patients under antidiabetic treatment (n=35). Serum betatrophin concentrations were determined by the enzyme-linked immunosorbent assay. Multivariate logistic regression was performed to assess the association between betatrophin concentration and DR. Serum betatrophin concentration was significantly associated with DR in T2DM patients under treatment (Odds Ratio 2.01; 95% Confidence Interval 1.12-3.60; p=0.019). Betatrophin concentrations were significantly increased in treated T2DM patients compared to the healthy subjects (4.17±0.60 vs. 0.54±0.07 ng/ml; p<0.001). Serum betatrophin concentrations are increased in T2DM patients under antidiabetic treatment and positively associated with diabetic retinopathy.

Microdosimetric analysis for high LET radiation.

For short range high linear energy transfer (LET) radiation therapy the biological effects are strongly affected by the heterogeneity of the specific energy (z) distribution delivered to tumour cells. Three-dimensional (3-D) dosimetry information at the cellular level is required for this study. An ideal approach would be the reconstruction of the cell and the radiation source microdistribution from sequential autoradiographic sections, which is, however, not a practical solution. In this paper, a novel microdosimetry analysis method, which obtains the specific energy (z) distribution directly from the morphological information in individual autoradiographic sections, is applied to human glioblastoma multifore (GBM) and normal brain tissue specimens in boron neutron capture therapy. The results are consistent with Monte Carlo simulation and demonstrate a uniform radiation source distribution in both GBM and normal brain tissues. We also hypothesise a biophysical model based on specific energy for survival analysis. The specific energy distributions to cell nuclei were calculated with a uniform radiation source distribution. By combining this microdosimetric analysis with measured cell survival data at the low dose region, a cell survival curve at high doses is predicted, which is consistent with the commonly used simple exponential curve model for high LET radiation.

RBE of the MIT epithermal neutron beam for crypt cell regeneration in mice.

The RBE of the new MIT fission converter epithermal neutron capture therapy (NCT) beam has been determined using intestinal crypt regeneration in mice as the reference biological system. Female BALB/c mice were positioned separately at depths of 2.5 and 9.7 cm in a Lucite phantom where the measured total absorbed dose rates were 0.45 and 0.17 Gy/ min, respectively, and irradiated to the whole body with no boron present. The gamma-ray (low-LET) contributions to the total absorbed dose (low- + high-LET dose components) were 77% (2.5 cm) and 90% (9.7 cm), respectively. Control irradiations were performed with the same batch of animals using 6 MV photons at a dose rate of 0.83 Gy/min as the reference radiation. The data were consistent with there being a single RBE for each NCT beam relative to the reference 6 MV photon beam. Fitting the data according to the LQ model, the RBEs of the NCT beams were estimated as 1.50 +/- 0.04 and 1.03 +/- 0.03 at depths of 2.5 and 9.7 cm, respectively. An alternative parameterization of the LQ model considering the proportion of the high- and low-LET dose components yielded RBE values at a survival level corresponding to 20 crypts (16.7%) of 5.2 +/- 0.6 and 4.0 +/- 0.7 for the high-LET component (neutrons) at 2.5 and 9.7 cm, respectively. The two estimates are significantly different (P = 0.016). There was also some evidence to suggest that the shapes of the curves do differ somewhat for the different radiation sources. These discrepancies could be ascribed to differences in the mechanism of action, to dose-rate effects, or, more likely, to differential sampling of a more complex dose-response relationship.

Development and application of an unconstrained technique for patient positioning in fixed radiation beams.

A flexible technique for positioning patients in fixed orientation radiation fields such as those used in neutron capture therapy (NCT) has been developed. The positioning technique employs reference points marked on the patient in combination with a 3D digitizer to determine the beam entry point and a template fitted to the patient's head is used to determine the proper beam orientation. A coordinate transformation between the CT image data and reference points on the patient determined by a least squares algorithm based on singular value decomposition is used to map the beam entry point from the planning system onto the patient. The technique was validated in a phantom study where the mean error in entry point placement was 1.3 mm. Five glioblastoma multiforme patients have been treated with NCT using this positioning technique.

Preliminary treatment planning and dosimetry for a clinical trial of neutron capture therapy using a fission converter epithermal neutron beam.

A Phase I/II clinical trial of neutron capture therapy (NCT) was conducted at Harvard-MIT using a fission converter epithermal neutron beam. This epithermal neutron beam has nearly ideal performance characteristics (high intensity and purity) and is well-suited for clinical use. Six glioblastoma multiforme (GBM) patients were treated with NCT by infusion of the tumor-selective amino acid boronophenylalanine-fructose (BPA-F) at a dose of 14.0 g/m(2) body surface area over 90 min followed by irradiation with epithermal neutrons. Treatments were planned using NCTPlan and an accelerated version of the Monte Carlo radiation transport code MCNP 4B. Treatments were delivered in two fractions with two or three fields. Field order was reversed between fractions to equalize the average blood boron concentration between fields. The initial dose in the dose escalation study was 7.0 RBEGy, prescribed as the mean dose to the whole brain volume. This prescription dose was increased by 10% to 7.7 RBEGy in the second cohort of patients. A pharmacokinetic model was used to predict the blood boron concentration for determination of the required beam monitor units with good accuracy; differences between prescribed and delivered doses were 1.5% or less. Estimates of average tumor doses ranged from 33.7 to 83.4 RBEGy (median 57.8 RBEGy), a substantial improvement over our previous trial where the median value of the average tumor dose was 25.8 RBEGy.

Estimate of absorbed dose based on two-dimensional autoradiographic information in internal radionuclide therapy.

In radiation therapies using radionuclides emitting short-range particles, such as radioimmunotherapy or boron neutron capture therapy, the biological effects are strongly affected by the heterogeneity of the absorbed dose distribution delivered to tumor cells. The three-dimensional (3D) information of the source distribution at the cellular level is required to accurately determine the absorbed dose distribution to the individual tumor cells. Two-dimensional distribution of cell and nuclide with a resolution of 1 microm can be obtained from individual tissue sections by microautoradiography. To obtain such information in 3D, an ideal approach would be to align the serial tissue sections from a block and analyze all of them. This is straightforward in theory, but extremely difficult in practice. Furthermore, every section in the block has to be processed and analyzed, and the usage of the data from this laborious work is very inefficient. An approach presented here is to estimate the absorbed dose based on individual sections without 3D reconstruction. It is realistically workable since it avoids the most difficult task of alignment for the serial tissue sections. In addition, the absorbed dose can be estimated based on a limited number of noncontiguous sections. The validity of this approach has been tested by a Monte Carlo simulation for two representative radionuclide configurations: (a) a uniform distribution of sources and (b) a cell membrane bound source distribution. With only a limited number of sampling sections, the uncertainties in the dose estimation were estimated to approximately 15% for short-range particles.

[Heavy ion radiation induced inactivation of human bronchial epithelial cells].

OBJECTIVE: To observe the cell inactivating effects of Li, C and F ions. METHOD: Li(Z = 3), C(Z = 6) and F(Z = 9) ion beams, with LETs of 100 keV/micron, 300 keV/micron and 1000 keV/micron, respectively were produced by HI-13 tandem accelerator at the Department of Nuclear Physics, China Institute of Atomic Energy. The human bronchial epithelium cell line (BEAS-2B) was irradiated with the designed doses ranging from 0.5 Gy to 6.0 Gy. After irradiation, the cells were cultured at 1000/flask and the survival fractions were calculated. RESULT: The cell survival fraction (SF, non-unit) have negative exponential relations with dose(D, Gy) as shown by the fitted equations: SF = EXP(-D/1.28)(Li); SF = EXP(-D/1.18)(C); SF = EXP(-D/2.09)(F), respectively. The sensitive parameters (D0, Gy) of radiation were D0 = 1.28; D0 = 1.18; D0 = 2.09, respectively. The patterns of cell survival were fitted to single target model. The relative biological effectiveness (RBE) for Li, C and F ions were 2.54, 2.67, 1.55, respectively, compared with D0 of gamma-ray irradiation. The inactivation cross sections for these ions were 12.5, 40.6 and 76.5 microns2 respectively. CONCLUSION: The effectiveness of radiation induced by heavy ions of Li, C and F was more serious than that of 60Co gamma-ray, and more than one particle traversal are needed to kill a cell on the average.

Ultrasound field calculation in a water-soft tissue medium.

An efficient numerical approximation for ultrasound field calculation in a two or three layer water-soft tissue medium is presented. It is extended from a method developed previously in a homogeneous medium. The emphasis of this study is to examine the conditions that are required for this approximation. Criteria are given for achieving an appropriate accuracy, which is verified by comparing it with the Rayleigh integral.

Modulation of phosphatidylinositol turnover on central nicotinic receptors.

AIM: To study the modulatory effects of phosphatidylinositol (PI) turnover on nicotinic receptors in CNS, and to study the relationship between brain nicotinic receptors and PI turnover. METHODS: Effects of inositol phosphatase inhibitor lithium chloride (LiCl) and muscarinic receptor agonist oxotremorine (Oxo) on nicotine-induced convulsions were investigated in mice. RESULTS: The effects of nicotine for producing convulsions were modified by LiCl 2.5-10 mmol.kg-1, revealing the convulsive effects of nicotine > 0.8 mg.kg-1 were increased by acute pretreatment with LiCl rather than oxotremorine. Mice were given LiCl 5.0 mmol.kg-1 once a day for 7 d, the ED50 value of nicotine for producing convulsions was increased from 0.58 to 0.97 mg.kg-1, suggesting that the sensitivity of central nicotinic receptors for mediating convulsions was decreased by chronic treatment with LiCl. CONCLUSION: The functions of central nicotinic receptors were modulated by PI turnover.

Design of an ultrasonic therapy system for breast cancer treatment.

This paper describes the design of a novel ultrasonic therapy system dedicated to the breast cancer treatment and the theoretical investigation of the heating characteristics of the system. The applicator is a cylinder comprised of a stack of rings. Each ring has up to 48 transducers mounted on the inside of the ring and directed towards the centre. The transducers operate in one of two frequency bands (1.8-2.8 MHz and 4.3-40.8 MHz), arranged alternately in each ring. During treatment the patient is positioned in prone position, with the breast immersed in water and surrounded by this array. This design was modelled and optimized by 3-D simulations for a variety of treatment conditions. The simulated results demonstrate that the system has an excellent capability to achieve and maintain a temperature distribution (41.5-44 degrees C) in a quadrant to a whole breast. Initial experiments using a single ring of transducers has been performed to verify the power deposition calculation.

A direct approach for the determination of absorbed dose from electron beams using non-water phantoms.

Non-water solid phantoms are often used in the determination of absorbed dose to water for electron beams. Protocols have been established and widely accepted. In these procedures, several assumptions in addition to the Spencer-Attix conditions are required, and several correction factors are needed. A direct approach, in which the conversion is carried out in a single step using a modified Spencer-Attix formula, is studied in this paper. The approach is consistent with the protocols for water phantom, and the conversion factors can be calculated using Monte Carlo simulation. The behavior of the conversion factors is described by comparing the results from the AAPM protocol and experiment data for three electron energies (6, 12, and 16 MeV). This study demonstrates that for beam calibration at dmax, the results from the new approach agree with those from the protocol with a maximum discrepancy of 1% for PMMA and 1.3% for polystyrene. For the depth dose measurement from near the surface to R80, the agreement is within 1.5% for PMMA, 2.5% for polystyrene, and 2.8% for electron solid water. It also demonstrates that for electron solid water, the new approach provides better agreement with experiment data for the beam calibration at d(max).

The spatial accuracy of cellular dose estimates obtained from 3D reconstructed serial tissue autoradiographs.

In order to better predict and understand the effects of radiopharmaceuticals used for therapy, it is necessary to determine more accurately the radiation absorbed dose to cells in tissue. Using thin-section autoradiography, the spatial distribution of sources relative to the cells can be obtained from a single section with micrometre resolution. By collecting and analysing serial sections, the 3D microscopic distribution of radionuclide relative to the cellular histology, and therefore the dose rate distribution, can be established. In this paper, a method of 3D reconstruction of serial sections is proposed, and measurements are reported of (i) the accuracy and reproducibility of quantitative autoradiography and (ii) the spatial precision with which tissue features from one section can be related to adjacent sections. Uncertainties in the activity determination for the specimen result from activity losses during tissue processing (4-11%), and the variation of grain count per unit activity between batches of serial sections (6-25%). Correlation of the section activity to grain count densities showed deviations ranging from 6-34%. The spatial alignment uncertainties were assessed using nylon fibre fiduciary markers incorporated into the tissue block, and compared to those for alignment based on internal tissue landmarks. The standard deviation for the variation in nylon fibre fiduciary alignment was measured to be 41 microns cm-1, compared to 69 microns cm-1 when internal tissue histology landmarks were used. In addition, tissue shrinkage during histological processing of up to 10% was observed. The implications of these measured activity and spatial distribution uncertainties upon the estimate of cellular dose rate distribution depends upon the range of the radiation emissions. For long-range beta particles, uncertainties in both the activity and spatial distribution translate linearly to the uncertainty in dose rate of < 15%. For short-range emitters (< 100 microns), such as alpha particle sources, the magnitude of the uncertainty in serial section alignment is comparable with the particle track length. Under these circumstances, dosimetric errors are introduced in proportion to the serial section alignment inaccuracy.

A miniature MOSFET radiation dosimeter probe.

Prototype miniature dosimeter probes have been designed, built, and characterized employing a small, radiation sensitive metal oxide semiconductor field effect transistor (MOSFET) chip to measure, in vivo, the total accumulated dose and dose rate as a function of time after internal administration of long range beta particle radiolabeled antibodies and in external high energy photon and electron beams. The MOSFET detector is mounted on a long narrow alumina substrate to facilitate electrical connection. The MOSFET, alumina substrate, and lead wires are inserted into a 16 gauge flexineedle, which, in turn, may be inserted into tissue. The radiation dosimeter probe has overall dimensions of 1.6 mm diam and 3.5 cm length. The MOSFET probe signals are read, stored, and analyzed using an automated data collection and analysis system. Initially, we have characterized the probe's response to long range beta particle emission from 90Y sources in solution and to high energy photon and electron beams from linear accelerators. Since the prototype has a finite substrate thickness, the angular dependence has been studied using beta particle emission from a 90Sr source. Temperature dependence and signal drift have been characterized and may be corrected for. Measurements made in spherical volumes containing 90Y with diameters less than the maximum electron range, to simulate anticipated geometries in animal models, agree well with Berger point kernel and EGS4 Monte Carlo calculations. The results from the prototype probes lead to design requirements for detection of shorter range beta particles used in radioimmunotherapy and lower photon energies used in brachytherapy.

[Etiological analysis of 246 cases of oculomotor palsy].

Based on etiological analysis of 246 cases of oculomotor palsy, the causes of the disease were firstly aneurysm of the skull base and intracranial inflammation, followed by intracranial tumor and skull injury. Aneurysm of the skull base with oculomotor palsy often manifested pupil dilation. Syndromes associated with oculomotor palsy were discussed.

Sampling techniques for the evaluation of treatment plans.

Sampling techniques using randomly distributed points and regular Cartesian grids were compared for the evaluation of volume, dose-volume histogram, tumor control, and normal tissue complication probabilities in radiation treatments. Particularly, the uncertainties associated with each sampling technique in estimating the dose-volume histograms for several dose distributions are analyzed in detail. It is found that the estimation of these parameters using sampling points on a regular Cartesian grid is, in general, significantly more efficient than using random points. This finding is different from other published results. The choice of grid size for sampling was analyzed according to the AAPM recommended uncertainty on the dose delivered to the patient. It was concluded that when grid sampling is used, a grid size of 0.5 cm is adequate for most plans to meet the guidelines.