A clinical 3D/4D CBCT-based treatment dose monitoring system.

To monitor delivered dose and trigger plan adaptation when deviation becomes unacceptable, a clinical treatment dose (Tx-Dose) reconstruction system based on three-dimensional (3D)/four-dimensional (4D)-cone beam computed tomograpy (CBCT) images was developed and evaluated on various treatment sites, particularly for lung cancer patient treated by stereotactic body radiation therapy (SBRT). This system integrates with our treatment planning system (TPS), Linacs recording and verification system (R&V), and CBCT imaging system, consisting of three modules: Treatment Schedule Monitoring module (TSM), pseudo-CT Generating module (PCG), and Treatment Dose Reconstruction/evaluation module (TDR). TSM watches the treatment progress in the R&V system and triggers the PCG module when new CBCT is available.

Evaluation of algebraic iterative image reconstruction methods for tetrahedron beam computed tomography systems.

Tetrahedron beam computed tomography (TBCT) performs volumetric imaging using a stack of fan beams generated by a multiple pixel X-ray source. While the TBCT system was designed to overcome the scatter and detector issues faced by cone beam computed tomography (CBCT), it still suffers the same large cone angle artifacts as CBCT due to the use of approximate reconstruction algorithms. It has been shown that iterative reconstruction algorithms are better able to model irregular system geometries and that algebraic iterative algorithms in particular have been able to reduce cone artifacts appearing at large cone angles.

A real time dose monitoring and dose reconstruction tool for patient specific VMAT QA and delivery.

Purpose: To develop a real time dose monitoring and dose reconstruction tool to identify and quantify sources of errors during patient specific volumetric modulated arc therapy (VMAT) delivery and quality assurance.

Methods: The authors develop a VMAT delivery monitor tool called linac data monitor that connects to the linac in clinical mode and records, displays, and compares real time machine parameters with the planned parameters. A new measure, called integral error, keeps a running total of leaf overshoot and undershoot errors in each leaf pair, multiplied by leaf width, and the amount of time during which the error exists in monitor unit delivery.

MO-D-BRB-08: BEST IN PHYSICS (THERAPY) - A Real Time Dose Monitoring and Dose Reconstruction Tool for Patient Specific VMAT QA and Delivery.

Purpose: To develop a real time dose monitoring and dose reconstruction tool to identify and quantify sources of errors during patient specific VMAT delivery and QAMethods: The VMAT delivery monitor tool called Linac Data Monitor (LDM) has been developed that connects to the linac in clinical mode and displays, records and compares real-time machine parameters to the planned parameters. A new quantity called integral error keeps a running total of leaf overshoot and undershoots errors in each leaf pair multiplied by leaf width and the amount of time during which error exists in MU delivery. Another tool reconstructs pinnacle format delivered plan based on the saved machine logfile and recalculates actual delivered dose in patient anatomy.

Programming in the small.

Academic medical centers, in general, and radiation oncology research, in particular, rely heavily on custom software tools and applications. The code development is typically the responsibility of a single individual or at most a small team. Often these individuals are not professional programmers but physicists, students, and physicians.

The quest for market exclusivity in biotechnology: navigating the patent minefield.

A patent is a legal device that grants an inventor market exclusivity over a new invention or medication. Market exclusivity can mean tremendous economic rewards for the patent holder because it provides the inventor with a monopoly over the invention for the 20-year patent term. Obtaining a patent and retaining market exclusivity can be a treacherous process, especially in the arena of biotechnology patents.

Immunostaining of human melanomas by a monoclonal antibody to B700 mouse melanoma antigen.

Previous studies have shown that B700, an albumin-like murine melanoma antigen, has a human homologue termed H700. Polyclonal antibodies to B700 also bind to all cultured human, swine and hamster melanoma cells, suggesting that B700 is a "pan-melanoma" antigen. The objects of this investigation were: (a) to determine if 2-3-3, a monoclonal antibody to B700, can be used to identify human melanomas in formalin-fixed, paraffin-embedded tissues, and (b) to determine the specificity and potential diagnostic value of 2-3-3.

Studies on the expression and immunogenicity of the B50 melanoma antigen and its relationship with calreticulin.

B50 is a 50 kDa protein antigen originally identified and isolated from cultured B16 murine melanoma cells; it is found in close association with a melanoma-specific antigen termed B700. Using a specific rabbit antiserum, B50 (or B50 cross-reactive molecules) has been shown to be expressed by 35 out of 36 cell lines, including melanomas, sarcomas, fibrosarcomas, carcinomas, gliomas, immortalized and primary fibroblasts, melanocyte and keratinocyte cell lines obtained from murine, human, hamster, swine, and canine donors. B50 expression is localized on the cellular membrane and in the cytoplasm in varying amounts in seven of the nine cell lines tested.

Novel experimental approaches to melanoma diagnosis and therapy.

We have investigated the potential use of immune therapies on the growth of melanoma metastases in a new animal model that more closely approximates the clinical situation. We have found that significant benefits towards decreased metastatic growth and subsequent animal survival can be achieved by treatment of tumor-bearing mice with melanoma-specific monoclonal antibodies or alternatively, with various types of monovalent or polyvalent vaccines. The beneficial effects of those vaccines can be significantly enhanced by concomitant interleukin-2 therapy.

Nude mouse model to study passive humoral immunotherapy directed against B16 F10 murine melanoma.

A model to study passive humoral immunotherapy of experimental melanoma was generated by subcutaneous injection of B16 F10 murine melanoma cells in the midtail of BALB/C nude (nu/nu) mice. Mice were challenged with melanoma cells pretreated: (1) with complete culture medium, (2) with 10% adjuvant control serum, (3) with 10% anti-fECA (formalinized extracellular antigens) immune serum, or (4) with a monoclonal antibody (mAB H2-3-3) specific for the B700 melanoma-associated antigen. All control mice challenged with melanoma cells pretreated either with culture medium or with medium containing adjuvant control serum (Groups I and II) died during the observation period of 84 days.

Further studies of the therapeutic effects of murine melanoma-specific monoclonal antibodies.

The results presented here further characterize four murine monoclonal antibodies (mAb) that recognize melanoma-specific antigens (9B6, T97, 2-3-1 and 2-3-3). These melanoma-specific mAbs are of the IgG2b isotype and are significantly therapeutic when administered systemically against established pulmonary melanoma metastases. Here we show a consistent and significant inhibition of the growth of melanoma lung metastases by all four mAbs and the existence of a time 'window' at days 5-8 after tumor inoculation for optimal therapy.

Cross-reactivity between murine melanoma antigen B700 and a human melanoma-associated antigen (M-66) recognized by autologous antibody: evidence suggesting shared epitopes.

We have previously reported the purification and partial characterization of a human melanoma-associated antigen (M-66) recognized by autologous antibody. This antigen was found to be an unusually acidic 66 kDa glycoprotein. In studies of murine melanoma, a 67-kDa albumin-like melanoma-associated antigen (MAA) isolated from B16 melanoma cells has also been reported by our laboratories.

Towards stoichiometric silver staining of proteins resolved in complex two-dimensional electrophoresis gels: real-time analysis of pattern development.

Toward the ultimate goal of deriving quantitative protein data from silver-stained proteins resolved in complex two-dimensional electrophoresis gels we have performed computerized real-time analysis during pattern protein "silver stain" development. Three points emerged from this study: (i) Development time is a far more important variable than originally envisioned. (ii) Previous studies which, on the basis of a single development time, sought to relate silver stain slope and threshold properties to amino acid composition are non-informative since it will be shown that slope values change markedly with development time.

Preimmunization of mice with formalinized extracellular antigens of melanoma in combination with IL-2 and surgical resection increased survival and tumor control in metastatic melanoma model.

Recently we found that immunization with formalized extracellular antigens (FECAs) could induce the production of specific antimelanoma antibodies and increase the defense mechanisms of antimelanoma cellular and humoral immunity. In experiments we used pathogen-free female mice C57BL/6 18-20 g. We injected FECA (0.

Generation of cytotoxic antibodies to the B16 murine melanoma using a formalinized vaccine.

The goal of our experiments was to determine the extent to which the humoral response to a melanoma vaccine elicits the production of cytotoxic antibodies in tumor-challenged mice. Mice were immunized with a vaccine produced from formalinized extracellular antigens (FECA) derived from B16 F10 melanomas. The production of antibodies that recognized the vaccine preparation was determined by ELISA, as was their cross-reactivity with the B700 melanoma antigen.

Proteinuria of B700, a 67 kD albumin-like melanoma-specific antigen.

B700 is a murine melanoma antigen that is closely related to, but distinct from, serum albumin. The present study examined the metabolic fate and anatomic distribution of radioiodinated B700 and mouse serum albumin (MSA) administered s.c.

B700 antigen as a component of an antimelanoma vaccine: formalinized extracellular antigens.

Formalin fixation has enjoyed widespread use in the preparation of antibacterial and other vaccines, but rather less use in antitumor vaccines. Previous studies from our laboratories have demonstrated the efficacy of antimelanoma vaccines in mice, produced from formalinized antigens shed by cultured melanoma cells. In this study, we provide evidence that the immunodominant component of that vaccine is the well-characterized B700 melanoma antigen.

Separation of proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of soluble, aqueous polymers: Ficoll and polyvinylpyrrolidone.

In previous studies we have demonstrated that water soluble polymers of dextran and methylcellulose, when incorporated into sodium dodecyl sulfate (SDS)-polyacrylamide gels, can be used to sharpen the protein bands. We have extended these studies to enhance the separations in the mid-molecular weight range. Enhanced separation of protein molecular weight markers between 30,000-67,000 was best achieved in SDS-gels containing 2.

Polyacrylamide gel electrophoresis in vertical, inverse and double-crossing gradients of soluble polymers.

The presence of soluble dextrans, methylcellulose and polyethylene glycol polymers incorporated into vertical sodium dodecyl sulfate (SDS)-polyacrylamide slabs during electrophoresis can have a pronounced effect on protein separations. The effects of various standard and inverse gradients of polymers on the electrophoretic mobility of marker proteins in 10% T, 2.66% C Laemmli-style SDS gels, and the effects of simultaneous pore size and polymer gradients were investigated.

Production of monoclonal antibodies against the B700 murine melanoma antigen and their antimetastatic properties.

Two unique murine melanoma antigens, termed B700 and B50, have been identified and isolated from several different murine melanoma cell lines. Both antigens can be detected on the cell surface, are actively shed in culture, and are often found in close association intracellularly. In previous studies, the antigen B700, which is related to serum albumin by biochemical and immunological criteria, was shown to function as a melanoma-specific tumor rejection antigen.

The use of radioactive bacteriophage proteins as X-Y markers for silver stained two-dimensional electrophoresis gels and quantification of the patterns.

We have demonstrated the feasibility of using bacteriophage ghost proteins, tritiated by metabolic labeling, as a set of standard markers for two-dimensional gels in which the proteins are to be detected by silver staining. The results indicate that a 2.5 microgram load of phage proteins yields a reproducible silver pattern of 48 spots.

Antigens of murine melanoma and their cross-species reactivity.

Many investigators have taken a two-stage approach to the study of tumor antigens. The first is the evaluation of antigens produced by animal tumors and the second is the determination of the extent to which animal antigens have relevant human homologs. Accordingly, we discuss the known protein antigens of murine melanoma with emphasis on those expressed by more than one species.