Clinically significant cardiac disease in patients with Hodgkin lymphoma treated with mediastinal irradiation.

This study assessed the cumulative incidence of clinically significant cardiac disease in 1279 Hodgkin lymphoma patients treated with mediastinal irradiation and quantified the standard incidence ratios (SIRs) and absolute excess risks of cardiac procedures compared with a normal matched population. Cox regression analysis was used to explore factors associated with cardiac complications. Poisson regression analysis of SIRs was used to estimate the excess risk of cardiac interventions from mediastinal irradiation. After a median follow-up of 14.7 years, 187 patients experienced 636 cardiac events and 89 patients required a cardiac procedure. 5-, 10-, 15-, and 20-year cumulative incidence rates of cardiac events were 2.2%, 4.5%, 9.6%, and 16%. SIRs for cardiac procedures were increased for coronary artery bypass graft (3.19), percutaneous intervention (1.55), implantable cardioverter defibrillator or pacemaker placement (1.9), valve surgery (9.19), and pericardial surgery (12.91). Absolute excess risks were 18.2, 19.3, 9.4, 14.1, and 4.7 per 10 000 person-years, respectively. Older age at diagnosis and male sex were predictors for cardiac events. However, younger age at diagnosis was associated with excess risk specifically from radiation therapy compared with the general population. These results may help guideline development for both the types and timing of cardiac surveillance in survivors of Hodgkin lymphoma.

Cellular and molecular chaperone fusion vaccines: targeting resistant cancer cell populations.

Molecular chaperone-based vaccines offer a number of advantages for cancer treatment. We have discussed the deployment of a vaccine prepared by gentle isolation of Hsp70 from tumour dendritic cell fusions (Hsp70 fusion vaccine). The vaccine was highly effective in triggering specific T cell immunity and in the treatment of tumour-bearing mice and the preparation was shown to retain an increased amount of tumour antigens compared to other chaperone-based isolates. This approach has the further advantage that tumour sub-populations could be used to prepare the Hsp70 fusion vaccine. Cellular fusion vaccines were made to specifically target drug-resistant cancer cells and tumour cell populations enriched in ovarian cancer stem cells (CSC). Such vaccines showed enhanced capacity to trigger T cell immunity to these resistant ovarian carcinoma populations. We have discussed the potential of using the cellular and Hsp70 fusion vaccine approaches in therapy of treatment-resistant cancer cells and its deployment in combination with ionising radiation or hyperthermia to enhance the effectiveness of both forms of therapy.

Ablative radiotherapy improves survival but does not cure autochthonous mouse models of prostate and colorectal cancer.

BACKGROUND: Genetically engineered mouse models (GEMMs) of cancer are powerful tools to study mechanisms of disease progression and therapy response, yet little is known about how these models respond to multimodality therapy used in patients. Radiation therapy (RT) is frequently used to treat localized cancers with curative intent, delay progression of oligometastases, and palliate symptoms of metastatic disease. METHODS: Here we report the development, testing, and validation of a platform to immobilize and target tumors in mice with stereotactic ablative RT (SART). Xenograft and autochthonous tumor models were treated with hypofractionated ablative doses of radiotherapy. RESULTS: We demonstrate that hypofractionated regimens used in clinical practice can be effectively delivered in mouse models. SART alters tumor stroma and the immune environment, improves survival in GEMMs of primary prostate and colorectal cancer, and synergizes with androgen deprivation in prostate cancer. Complete pathologic responses were achieved in xenograft models, but not in GEMMs. CONCLUSIONS: While SART is capable of fully ablating xenografts, it is unable to completely eradicate disease in GEMMs, arguing that resistance to potentially curative therapy can be modeled in GEMMs.

Mice can be used to model the types of cancer seen in people to investigate the effects of cancer therapies, such as radiation. Here, we apply radiation therapy treatments that are able to cure cancer in humans to mice that have cancer of the prostate or colorectum. We show that the mice do not experience many side effects and that the tumours reduce in size, but in some cases show progression after treatment. Our study demonstrates that mice can be used to better understand how human cancers respond to radiation treatment, which can lead to the development of improved treatments and treatment schedules.

Organ deformation and dose coverage in robotic respiratory-tracking radiotherapy.

PURPOSE: Respiratory motion presents a significant challenge in stereotactic body radiosurgery. Respiratory tracking that follows the translational movement of the internal fiducials minimizes the uncertainties in dose delivery. However, the effect of deformation, defined as any changes in the body and organs relative to the center of fiducials, remains unanswered. This study investigated this problem and a possible solution. METHODS AND MATERIALS: Dose delivery using a robotic respiratory-tracking system was studied with clinical data. Each treatment plan was designed with the computed tomography scan in the end-expiration phase. The planned beams were applied to the computed tomography scan in end-inspiration following the shift of the fiducials. The dose coverage was compared with the initial plan, and the uncertainty due to the deformation was estimated. A necessary margin from the clinical target volume to the planning target volume was determined to account for this and other sources of uncertainty. RESULTS: We studied 12 lung and 5 upper abdomen lesions. Our results demonstrated that for lung patients with properly implanted fiducials a 3-mm margin is required to compensate for the deformation and a 5-mm margin is required to compensate for all uncertainties. Our results for the upper abdomen tumors were still preliminary but indicated a similar result, although a larger margin might be required. CONCLUSION: The effect of body deformation was studied. We found that adequate dose coverage for lung tumors can be ensured with proper fiducial placement and a 5-mm planning target volume margin. This approach is more practical and effective than a recent proposal to combine four-dimensional planning with respiratory tracking.

Reduced Mortality Risk in the Recent Era in Early-Stage Hodgkin Lymphoma Patients Treated With Radiation Therapy With or Without Chemotherapy.

PURPOSE: To determine the effect of treatment changes over time on all-cause mortality risk in patients with early-stage Hodgkin lymphoma (HL) after radiation therapy. The long-term survivorship of those with HL necessitates quantification of the late risk of mortality from HL and other causes. METHODS AND MATERIALS: An institutional review board-approved retrospective study was conducted using a multi-institutional database of 1541 stage I and II HL patients treated from 1968 to 2007 with radiation therapy alone or combined-modality treatment. The analytic methods included cumulative incidence function, Kaplan-Meier estimates and log-rank tests for overall survival (OS) differences, and Cox proportional hazards modeling. RESULTS: The median age at diagnosis was 27 years. At a median follow-up of 15.2 years (35% of patients with >20 years of follow-up), 395 patients had died of all causes, including 85 HL, 168 second malignancy (25 hematologic and 143 nonhematologic), 70 cardiovascular, and 21 pulmonary deaths. The cumulative incidence of non-HL mortality had surpassed HL mortality at 8.3 years. For patients treated from 1968 to 1982, 1983 to 1992, and 1993 to 2007, the 15-year OS rates were 78%, 85%, and 88%, respectively (P=.0016). On Cox proportional hazards analysis, age, B symptoms, and number of disease sites were significantly associated with all-cause mortality in the first decade of follow-up, with a trend toward significance for radiation field extent. CONCLUSIONS: The all-cause mortality risk was significantly lower for patients treated in the most recent era during the first decade of follow-up, likely due to improved HL therapy resulting in a higher cure rate and lower treatment-related toxicity from smaller radiation fields. Current efforts toward radiation treatment reduction might further reduce the long-term mortality risk for these patients.

Academic career selection and retention in radiation oncology: the Joint Center for Radiation Therapy experience.

PURPOSE: The United States healthcare system has witnessed declining reimbursement and increasing documentation requirements for longer than 10 years. These have decreased the time available to academic faculty for teaching and mentorship. The impact of these changes on the career choices of residents is unknown. The purpose of this report was to determine whether changes have occurred during the past decade in the proportion of radiation oncology trainees from a single institution entering and staying in academic medicine. METHODS AND MATERIALS: We performed a review of the resident employment experience of Harvard Joint Center for Radiation Therapy residents graduating during 13 recent consecutive years (n = 48 residents). The outcomes analyzed were the initial selection of an academic vs. nonacademic career and career changes during the first 3 years after graduation. RESULTS: Of the 48 residents, 65% pursued an academic career immediately after graduation, and 44% remained in academics at the last follow-up, after a median of 6 years. A later graduation year was associated with a decrease in the proportion of graduates immediately entering academic medicine (odds ratio, 0.78; 95% confidence interval, 0.65-0.94). However, the retention rate at 3 years of those who did immediately enter academics increased with a later graduation year (p = 0.03). CONCLUSION: During a period marked by notable changes in the academic healthcare environment, the proportion of graduating Harvard Joint Center for Radiation Therapy residents pursuing academic careers has been declining; however, despite this decline, the retention rates in academia have increased.

Induction of heat shock proteins by heregulin beta1 leads to protection from apoptosis and anchorage-independent growth.

Elevation of heat shock protein (HSP) levels is widespread in cancer and predicts a poor prognosis and resistance to therapy. We show that HSP elevation in tumor cells can be induced by the highly malignant factor heregulin beta1 (HRGbeta1), which induces HSP expression through heat shock transcription factor 1 (HSF1). Inactivation of the hsf1 gene prevents HSP induction by HRGbeta1. HSP expression is induced through a cascade response initiated by HRGbeta1 binding to c-erbB receptors on the cell surface and which leads to the inhibition of intracellular HSF1 antagonist glycogen synthase kinase 3. HSF1 activated by this pathway plays a key role in the protection of cells from apoptosis and the mediation of anchorage independent growth by HRGbeta1, indicating a role for HSF1 in this tumorigenic pathway.

Long-term outcome and mortality trends in early-stage, Grade 1-2 follicular lymphoma treated with radiation therapy.

PURPOSE: To analyze long-term outcomes and causes of death in patients receiving radiation therapy (RT) for localized, low-grade follicular lymphoma. METHODS AND MATERIALS: Between 1972 and 2000, 106 patients with Stage I-II, Grade 1-2 follicular lymphoma received RT alone or radiation and chemotherapy (RT/CT). Seventy-four percent had Stage I, and 26% had Stage II disease. Seventy-six percent received RT alone, and 24% received combined RT/CT. Second malignancy rates were compared with an age- and sex-matched population. RESULTS: Median follow-up was 12 years. Median survival time was 19 years. The 5-, 10-, and 15-year overall survival (OS) rates were 93%, 75%, and 62%, respectively. Age > or = 60 was the only significant adverse prognostic factor with respect to OS. There were 35 deaths, 20 of which were attributable to lymphoma. Freedom from treatment failure (FFTF) rates at 5, 10, and 15 years were 72%, 46%, and 39%, respectively. Forty-seven patients (48%) relapsed. Tumor size > 3 cm was the only significant adverse factor for FFTF. Observed incidence of second malignancy did not significantly exceed expected incidence. CONCLUSIONS: Although patients with early-stage, low-grade follicular lymphoma have long median survival, the leading cause of death remains lymphoma. However, patients receiving RT do not have significantly elevated cumulative incidence of second malignancy.

Extracellular HSP70 binding to surface receptors present on antigen presenting cells and endothelial/epithelial cells.

Extracellular HSP70 has been found to participate in both innate and adaptive immune responses. However, little is known about the molecular mechanisms that mediate this process. Previous reports suggest that HSP70 interacts with antigen presenting cells (APC) through a plethora of surface receptors. In this study, we have examined the relative binding of potential HSP70 receptors and found high affinity binding to LOX-1 but not other structures with a role in HSP70-APC interactions such as LRP/CD91, CD40, TLR2, TLR4 or another c-type lectin family member (DC-SIGN) closely related to LOX-1. In addition to APC, HSP70 can avidly bind to non-APC cell lines, especially those from epithelial or endothelial background.

Anemia, tumor hypoxemia, and the cancer patient.

PURPOSE: To review the impact of anemia/tumor hypoxemia on the quality of life and survival in cancer patients, and to assess the problems associated with the correction of this difficulty. METHODS: MEDLINE searches were performed to find relevant literature regarding anemia and/or tumor hypoxia in cancer patients. Articles were evaluated in order to assess the epidemiology, adverse patient effects, anemia correction guidelines, and mechanisms of hypoxia-induced cancer cell growth and/or therapeutic resistance. Past and current clinical studies of radiosensitization via tumor oxygenation/hypoxic cell sensitization were reviewed. All clinical studies using multi-variate analysis were analyzed to show whether or not anemia and/or tumor hypoxemia affected tumor control and patient survival. Articles dealing with the correction of anemia via transfusion and/or erythropoietin were reviewed in order to show the impact of the rectification on the quality of life and survival of cancer patients. RESULTS: Approximately 40-64% of patients presenting for cancer therapy are anemic. The rate of anemia rises with the use of chemotherapy, radiotherapy, and hormonal therapy for prostate cancer. Anemia is associated with reductions both in quality of life and survival. Tumor hypoxemia has been hypothesized to lead to tumor growth and resistance to therapy because it leads to angiogenesis, genetic mutations, resistance to apoptosis, and a resistance to free radicals from chemotherapy and radiotherapy. Nineteen clinical studies of anemia and eight clinical studies of tumor hypoxemia were found that used multi-variate analysis to determine the effect of these conditions on the local control and/or survival of cancer patients. Despite differing definitions of anemia and hypoxemia, all studies have shown a correlation between low hemoglobin levels and/or higher amounts of tumor hypoxia with poorer prognosis. Radiosensitization through improvements in tumor oxygenation/hypoxic cell sensitization has met with limited success via the use of hyperbaric oxygen, electron-affinic radiosensitizers, and mitomycin. Improvements in tumor oxygenation via the use of carbogen and nicotinamide, RSR13, and tirapazamine have shown promising clinical results and are all currently being tested in Phase III trials. The National Comprehensive Cancer Network (NCCN) guidelines recommend transfusion or erythropoietin for symptomatic patients with a hemoglobin of 10-11 g/dl and state that erythropoietin should strongly be considered if hemoglobin falls to less than 10 g/dl. These recommendations were based on studies that revealed an improvement in the quality of life of cancer patients, but not patient survival with anemia correction. Phase III studies evaluating the correction of anemia via erythropoietin have shown mixed results with some studies reporting a decrease in patient survival despite an improvement in hemoglobin levels. Diverse functions of erythropoietin are reviewed, including its potential to inhibit apoptosis via the JAK2/STAT5/BCL-X pathway. Correction of anemia by the use of blood transfusions has also shown a decrement in patient survival, possibly through inflammatory and/or immunosuppressive pathways. CONCLUSIONS: Anemia is a prevalent condition associated with cancer and its therapies. Proper Phase III trials are necessary to find the best way to correct anemia for specific patients. Future studies of erythropoietin must evaluate the possible anti-apoptotic effects by directly assessing the tumor for erythropoietin receptors or the presence of the JAK2/STAT5/BCL-X pathway. Due to the ability of transfusions to cause immunosuppression, most probably through inflammatory pathways, it may be best to study the effects of transfusion with the prolonged use of anti-inflammatory medications.

Mid- and post-ABVD gallium scanning predicts for recurrence in early-stage Hodgkin's disease.

PURPOSE: To determine the efficacy of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) for patients with Hodgkin's disease and to identify predictors of outcome with this regimen. METHODS: Between 1987 and 1998, 175 patients with Stage I-IV Hodgkin's disease received ABVD as part of initial treatment. Overall survival (OS), freedom-from-treatment-failure (FFTF), and progression-free survival (PFS) were calculated using the Kaplan-Meier technique. Log-rank tests were used to identify univariate predictors of OS, FFTF, and PFS. Specifically, restaging gallium scan results and clinical response after chemotherapy were separately evaluated. RESULTS: The median follow-up time was 64 months. The 5-year OS, FFTF, and PFS rates were 90%, 85%, and 82%, respectively. For Stage I-II patients, restaging gallium scan results and clinical response after chemotherapy were highly predictive of OS, FFTF, and PFS (p < 0.0001). Other significant predictors for higher OS included age <50 (p = 0.002), female gender (p = 0.047), and absence of B symptoms (p = 0.043). Of the 20 patients with a positive restaging gallium scan, 4 received high-dose therapy and 16 continued with conventional-dose therapy or received no further treatment. Of these 16 patients, 11 (69%) were disease-free at last follow-up. CONCLUSIONS: Although a positive mid- or postchemotherapy gallium scan was an adverse prognostic factor for OS, FFTF, and PFS, continued treatment with conventional-dose therapy may be adequate in selected patients with positive scans.

Expression of heat shock proteins and heat shock protein messenger ribonucleic acid in human prostate carcinoma in vitro and in tumors in vivo.

Heat shock proteins (HSPs) are thought to play a role in the development of cancer and to modulate tumor response to cytotoxic therapy. In this study, we have examined the expression of hsf and HSP genes in normal human prostate epithelial cells and a range of prostate carcinoma cell lines derived from human tumors. We have observed elevated expressions of HSF1, HSP60, and HSP70 in the aggressively malignant cell lines PC-3, DU-145, and CA-HPV-10. Elevated HSP expression in cancer cell lines appeared to be regulated at the post-messenger ribonucleic acid (mRNA) levels, as indicated by gene chip microarray studies, which indicated little difference in heat shock factor (HSF) or HSP mRNA expression between the normal and malignant prostate cell lines. When we compared the expression patterns of constitutive HSP genes between PC-3 prostate carcinoma cells growing as monolayers in vitro and as tumor xenografts growing in nude mice in vivo, we found a marked reduction in expression of a wide spectrum of the HSPs in PC-3 tumors. This decreased HSP expression pattern in tumors may underlie the increased sensitivity to heat shock of PC-3 tumors. However, the induction by heat shock of HSP genes was not markedly altered by growth in the tumor microenvironment, and HSP40, HSP70, and HSP110 were expressed abundantly after stress in each growth condition. Our experiments indicate therefore that HSF and HSP levels are elevated in the more highly malignant prostate carcinoma cells and also show the dominant nature of the heat shock-induced gene expression, leading to abundant HSP induction in vitro or in vivo.

Persistent viral shedding during asymptomatic Aleutian mink disease parvoviral infection in a ferret.

A 2-year-old domestic ferret that appeared clinically healthy was repeatedly seropositive for Aleutian mink disease parvovirus (ADV) over a 2-year observation period. Antibody titers, determined by counter-immunoelectrophoresis, ranged from 1024 to 4096. Viral DNA also was identified in serum, urine, feces, and blood cell fractions by polymerase chain reaction analysis. Ultimately, DNA in situ hybridization revealed ADV DNA in histologic sections of various tissues and organs. These data indicate that this asymptomatic ferret was persistently infected with ADV.

A three-field breast treatment technique with precise geometric matching using multileaf collimator-equipped linear accelerators.

PURPOSE: Many authors have studied the problems associated with the three-field breast treatment, yet the proposed solutions present their own difficulties. This study presents a technique that overcomes these difficulties, reduces scatter to the contralateral breast, and improves setup reproducibility. METHODS AND MATERIALS: Patients are set up with both arms raised superiorly on a breast board. A precise field-match is achieved by rotating the couch and collimator of the tangents, while the supraclavicular field is half-beam blocked using an independent jaw. The posterior borders of the tangents are conformally defined by multileaf collimation. Measurements were performed to verify the field matching and evaluate scatter doses. RESULT: A smooth dose transition was found at the match line at all depths. Corner blocks and lower wedges were not used, which reduced the scatter to the contralateral breast compared with our prior technique. CONCLUSION: The technique achieves a precise match while removing constraints on the tangents' length and decreasing scatter dose. Procedures for simulation, planning, and treatment have been devised, along with a new patient setup routine incorporating orthogonal setup films and tattoos. This technique has been successfully implemented in routine treatment since September 2001. A program calculating the setup parameters is available at our website.

Thyroid malignancies in survivors of Hodgkin lymphoma.

PURPOSE: To quantify the incidence of thyroid cancer after Hodgkin lymphoma (HL) and determine disease characteristics, risk factors, and treatment outcomes. METHODS AND MATERIALS: Thyroid cancer cases were retrospectively identified from a multi-institutional database of 1981 HL patients treated between 1969 and 2008. Thyroid cancer risk factors were evaluated by a Poisson regression model. RESULTS: With a median follow-up duration of 14.3 years (range, 0-41.2 years), 28 patients (1.4%) developed a thyroid malignancy. The overall incidence rate (expressed as the number of cases per 10,000 person-years) and 10-year cumulative incidence of thyroid cancer were 9.6 and 0.26%, respectively. There were no observed cases of thyroid malignancy in patients who received neck irradiation for HL after age 35 years. Age <20 years at HL diagnosis and female sex were significantly associated with thyroid cancer. The incidence rates of females aged <20 at HL diagnosis in the first 10 years, ≥10 years, ≥15 years, and ≥20 years after treatment were 5, 31, 61, and 75 cases per 10,000 person-years of follow-up, respectively. At a median follow-up of 3.5 years after the thyroid cancer diagnosis, 26 patients (93%) were alive without disease, 1 (4%) was alive with metastatic disease, and 1 (4%) died of metastatic disease, at 6 and 3.6 years after the thyroid cancer diagnosis, respectively. CONCLUSIONS: Although HL survivors have an increased risk for thyroid cancer, the overall incidence is low. Routine thyroid cancer screening may benefit females treated at a young age and ≥10 years from HL treatment owing to their higher risk, which increases over time.

Bending the cost curve: a unique collaboration between radiation oncologists and Blue Cross Blue Shield of Massachusetts to optimize the use of advanced technology.

PURPOSE: Intensity-modulated radiation therapy (IMRT) limits the dose of radiation to critical normal tissue structures and can be applied to the management of most cancers treated with radiation therapy. Because of increased treatment planning time and quality assurance, IMRT is costly. Blue Cross Blue Shield of Massachusetts (BCBSMA) and the Massachusetts Radiation Oncology Physicians Advisory Council (PAC) developed a strategy to develop standards for the appropriate use of IMRT. METHODS: Normal tissue volume guidelines were established in multiple oncology disease areas and body site regions. Guidelines were activated in September 2011, and the use of IMRT per case was tracked quarterly by BCBSMA staff. RESULTS: During the first year of activation of the volume-based guidelines, use of IMRT decreased by 17% in Massachusetts, in contrast to a 20% increase during the previous year. CONCLUSIONS: The normal tissue-based guidelines have decreased the use of IMRT in Massachusetts; increased the use of 3D treatment; continued communication between treating radiation oncologists and an insurance organization responsible for cost and quality in medicine; increased cost savings; enabled an efficient appeal process; and provided optimal, cost-effective patient care. This may prove to be an effective model for other disciplines and other developing and maturing radiation technologies.

Heat shock proteins, autoimmunity, and cancer treatment.

Heat shock proteins (HSPs) have been linked to the therapy of both cancer and inflammatory diseases, approaches that utilize contrasting immune properties of these proteins. It would appear that HSP family members Hsp60 and Hsp70, whether from external sources or induced locally during inflammation, can be processed by antigen-presenting cells and that HSP-derived epitopes then activate regulatory T cells and suppress inflammatory diseases. These effects also extend to the HSP-rich environments of cancer cells where elevated HSP concentrations may participate in the immunosuppressive tumor milieu. However, HSPs can also be important mediators of tumor immunity. Due to their molecular chaperone properties, some HSPs can bind tumor-specific peptides and deliver them deep into the antigen-processing pathways of antigen-presenting cells (APCs). In this context, HSP-based vaccines can activate tumor-specific immunity, trigger the proliferation and CTL capabilities of cancer-specific CD8+ T cells, and inhibit tumor growth. Further advances in HSP-based anticancer immunotherapy appear to involve improving the properties of the molecular chaperone vaccines by enhancing their antigen-binding properties and combating the immunosuppressive tumor milieu to permit programming of active CTL capable of penetrating the tumor milieu and specifically targeting tumor cells.

Frameless angiogram-based stereotactic radiosurgery for treatment of arteriovenous malformations.

PURPOSE: Stereotactic radiosurgery (SRS) is an effective alternative to microsurgical resection or embolization for definitive treatment of arteriovenous malformations (AVMs). Digital subtraction angiography (DSA) is the gold standard for pretreatment diagnosis and characterization of vascular anatomy, but requires rigid frame (skull) immobilization when used in combination with SRS. With the advent of advanced proton and image-guided photon delivery systems, SRS treatment is increasingly migrating to frameless platforms, which are incompatible with frame-based DSA. Without DSA as the primary image, target definition may be less than optimal, in some cases precluding the ability to treat with a frameless system. This article reports a novel solution. METHODS AND MATERIALS: Fiducial markers are implanted into the patient's skull before angiography. Angiography is performed according to the standard clinical protocol, but, in contrast to the previous practice, without the rigid frame. Separate images of a specially designed localizer box are subsequently obtained. A target volume projected on DSA can be transferred to the localizer system in three dimensions, and in turn be transferred to multiple CT slices using the implanted fiducials. Combined with other imaging modalities, this "virtual frame" approach yields a highly precise treatment plan that can be delivered by frameless SRS technologies. RESULTS: Phantom measurements for point and volume targets have been performed. The overall uncertainty of placing a point target to CT is 0.4 mm. For volume targets, deviation of the transformed contour from the target CT image is within 0.6 mm. The algorithm and software are robust. The method has been applied clinically, with reliable results. CONCLUSIONS: A novel and reproducible method for frameless SRS of AVMs has been developed that enables the use of DSA without the requirement for rigid immobilization. Multiple pairs of DSA can be used for better conformality. Further improvement, including using nonimplanted fiducials, is potentially feasible.

Heat shock proteins and cancer vaccines: developments in the past decade and chaperoning in the decade to come.

Molecular chaperone-peptide complexes extracted from tumors (heat shock protein [HSP] vaccines) have been intensively studied in the preceding two decades, proving to be safe and effective in treating a number of malignant diseases. They offer personalized therapy and target a cross-section of antigens expressed in patients' tumors. Future advances may rely on understanding the molecular underpinnings of this approach to immunotherapy. One property common to HSP vaccines is the ability to stimulate antigen uptake by scavenger receptors on the antigen-presenting cell surface and trigger T-lymphocyte activation. HSPs can also induce signaling through Toll-Like receptors in a range of immune cells and this may mediate the effectiveness of vaccines.