Single-Qubit Error Mitigation by Simulating Non-Markovian Dynamics.

Quantum simulation is a powerful tool to study the properties of quantum systems. The dynamics of open quantum systems are often described by completely positive (CP) maps, for which several quantum simulation schemes exist. Such maps, however, represent only a subset of a larger class of maps: the general dynamical maps which are linear, Hermitian preserving, and trace preserving but not necessarily positivity preserving. Here we present a simulation scheme for these general dynamical maps, which occur when the underlying system-reservoir model undergoes entangling (and thus non-Markovian) dynamics. Such maps also arise as the inverse of CP maps, which are commonly used in error mitigation. We illustrate our simulation scheme on an IBM quantum processor, demonstrating its ability to recover the initial state of a Lindblad evolution. This paves the way for a novel form of quantum error mitigation. Our scheme only requires one ancilla qubit as an overhead and a small number of one and two qubit gates. Consequently, we expect it to be of practical use in near-term quantum devices.

MR Imaging and Clinical Characteristics of Diffuse Glioneuronal Tumor with Oligodendroglioma-like Features and Nuclear Clusters.

BACKGROUND AND PURPOSE: Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC) is a new, molecularly defined glioneuronal CNS tumor type. The objective of the present study was to describe MR imaging and clinical characteristics of patients with DGONC. MATERIALS AND METHODS: Preoperative MR images of 9 patients with DGONC (median age at diagnosis, 9.9 years; range, 4.2-21.8 years) were reviewed. RESULTS: All tumors were located superficially in the frontal/temporal lobes and sharply delineated, displaying little mass effect. Near the circle of Willis, the tumors encompassed the arteries. All except one demonstrated characteristics of low-to-intermediate aggressiveness with high-to-intermediate T2WI and ADC signals and bone remodeling. Most tumors (n = 7) showed a homogeneous ground-glass aspect on T2-weighted and FLAIR images. On the basis of the original histopathologic diagnosis, 6 patients received postsurgical chemo-/radiotherapy, 2 were irradiated after surgery, and 1 patient underwent tumor resection only. At a median follow-up of 61 months (range, 10-154 months), 6 patients were alive in a first complete remission and 2 with stable disease 10 and 21 months after diagnosis. The only patient with progressive disease was lost to follow-up. Five-year overall and event-free survival was 100% and 86±13%, respectively. CONCLUSIONS: This case series presents radiomorphologic characteristics highly predictive of DGONC that contrast with the typical aspects of the original histopathologic diagnoses. This presentation underlines the definition of DGONC as a separate entity, from a clinical perspective. Complete resection may be favorable for long-term disease control in patients with DGONC. The efficacy of nonsurgical treatment modalities should be evaluated in larger series.

Intensity modulated radiotherapy as neoadjuvant chemoradiation for the treatment of patients with locally advanced pancreatic cancer. Outcome analysis and comparison with a 3D-treated patient cohort.

BACKGROUND: To evaluate outcome after intensity modulated radiotherapy (IMRT) compared to 3D conformal radiotherapy (3D-RT) as neoadjuvant treatment in patients with locally advanced pancreatic cancer (LAPC). MATERIALS AND METHODS: In total, 57 patients with LAPC were treated with IMRT and chemotherapy. A median total dose of 45 Gy to the PTV_baseplan and 54 Gy to the PTV_boost in single doses of 1.8 Gy for the PTV_baseplan and median single doses of 2.2 Gy in the PTV_boost were applied. Outcomes were evaluated and compared to a large cohort of patients treated with 3D-RT. RESULTS: Overall treatment was well tolerated in all patients and IMRT could be completed without interruptions. Median overall survival was 11 months (range 5-37.5 months). Actuarial overall survival at 12 and 24 months was 36 % and 8 %, respectively. A significant impact on overall survival could only be observed for a decrease in CA 19-9 during treatment, patients with less pre-treatment CA 19-9 than the median, as well as weight loss during treatment. Local progression-free survival was 79 % after 6 months, 39 % after 12 months, and 13 % after 24 months. No factors significantly influencing local progression-free survival could be identified. There was no difference in overall and progression-free survival between 3D-RT and IMRT. Secondary resectability was similar in both groups (26 % vs. 28 %). Toxicity was comparable and consisted mainly of hematological toxicity due to chemotherapy. CONCLUSION: IMRT leads to a comparable outcome compared to 3D-RT in patients with LAPC. In the future, the improved dose distribution, as well as advances in image-guided radiotherapy (IGRT) techniques, may improve the use of IMRT in local dose escalation strategies to potentially improve outcome.

Rare cancers in children - The EXPeRT Initiative: a report from the European Cooperative Study Group on Pediatric Rare Tumors.

The low incidence and the heterogeneity of very rare tumors (VRTs) demand for international cooperation. In 2008, EXPeRT (European Cooperative Study Group for Pediatric Rare Tumors) was founded by national groups from Italy, France, United Kingdom, Poland and Germany. The first aims of EXPeRT were to agree on a uniform definition of VRTs and to develop the currently most relevant scientific questions. Current initiatives include international data exchange, retrospective and prospective studies of specific entities, and the development of harmonized and internationally recognized guidelines. Moreover, EXPeRT established a network for expert consultation to assist in clinical decision in VRTs.

Malignant peritoneal mesothelioma in a 16-year-old girl: presentation of a rare disease.

Malignant peritoneal mesothelioma is extremely rarely seen in young patients.A 16 year-old girl presented with appendicitis-like acute abdominal pain. Intra-operatively, multiple confluent peritoneal nodules were seen on the entire greater omentum and in the pelvis infiltrating the uterus and both ovaries. Biopsies were obtained and interpreted as serous ovarian carcinoma. Radical surgical resection and hyperthermic intraperitoneal chemotherapy -(HIPEC) with carboplatin was performed and followed by 2 cycles of carboplatin/paclitaxel. Histological reevaluation showed characteristic features of epithelioid peritoneal mesothelioma and ruled out serous ovarian cancer. Therapy was continued with 6 cycles of pemetrexed/cisplatin.3 months after end of chemotherapy vital tumor tissue was found in the recess behind the liver, which could be resected completely. The patient is currently disease-free 17 months after initial diagnosis.Malignant peritoneal mesothelioma in young female patients might be under-recognized and possibly misdiagnosed as ovarian serous carcinoma in some cases. International and interdisciplinary cooperation is necessary in order to provide evidence based guidelines for diagnosis and treatment in the future.

Malignant pancreatic tumors in children and young adults: evaluation of 228 patients identified through the Surveillance, Epidemiology, and End Result (SEER) database.

BACKGROUND: Malignant pancreatic tumors are rare in young patients, few epidemiologic data are available. We reviewed prognostic factors and outcome of 228 patients <30 years with malignant pancreatic tumors identified through the U.S. National Cancer Institute's SEER (Surveillance, Epidemiology, and End Results) Public-use Database from 1973 to 2004. METHODS: Cases were grouped using the ICD-O-3. 5-year overall survival (OAS) was assessed by gender, ethnicity, SEER stage, and 5-year age intervals using univariate and Cox regression analysis. RESULTS: 228 patients with malignant pancreatic tumors were identified, resulting in an incidence of 0.46/million (100 carcinomas, 85 endocrine tumors, 8 solid pseudopapillary neoplasms (SPN), 11 pancreatoblastomas) in the USA. OAS was worse in males than females (37% vs. 55%, p=0.005). OAS according to stage was 87%, 68%, 21% for local (n=54), regional (n=42), distant metastatic disease (n=108), respectively. OAS of patients with carcinoma was 33%, endocrine tumors 58%, SPNs 88%, pancreatoblastomas 66%. Cox regression revealed stage (p=< 0.001), histology (p=< 0.001), age group (p=0.05) to be independent prognostic factors. CONCLUSION: Malignant pancreatic tumors are extremely rare in children and young adults. Entities change over the age groups towards more carcinomas with worse outcome in older patients. Tumor stage, histology and age group are important predictors for outcome. International collaboration is needed to learn more about pediatric pancreatic tumors.

Networking for children and adolescents with very rare tumors: foundation of the GPOH Pediatric Rare Tumor Group.

In comparison to cancer in adults, virtually all cancers of childhood and adolescence are rare. Nevertheless, there is a rather ill-defined group of tumors that are not only exceptionally rare but also do not fall into the major clinical categories of childhood cancers. Thus, a substantial proportion of these exceptionally rare tumors are not registered within clinical registries or prospective therapy optimization studies. Only recently, major attention has been drawn to the diagnostic assessment and treatment of children and adolescents with such orphan diseases. In 2006, the RARE TUMOR GROUP has been established within the German Society of Pediatric Oncology and Hematology (GPOH). This working group includes experts from Pediatric Oncology, Pediatric Surgery, Pediatric Pathology, Medical, Dermatologic and Radiation Oncology as well as Pediatric Epidemiology. The major aim of the rare tumor group is to integrate these patients into the diagnostic and therapeutic network successfully established in the pediatric oncologic society. Thus, the group aims at fostering the exchange of experience in the treatment of rare tumors between medical centers and to include patients in the diagnostic and therapeutic reference network. In addition, an information platform shall be established that will be accessible to treating physicians, patients and their parents. More information and better registration shall be established by active data accrual on a regular basis and by the implementation of a data base including diagnostic and therapeutic data of patients with rare tumors. These efforts as presented in this article as well as an intensified international collaboration will allow us to provide children and adolescents with rare tumors the best possible care.

Comparison of epirubicin and doxorubicin cardiotoxicity in children and adolescents treated within the German Cooperative Soft Tissue Sarcoma Study (CWS).

PURPOSE: Up to now, cardiotoxicity of epirubicin has been studied almost exclusively in adult cancer patients. The aim of this study was to investigate epirubicin in children and adolescents, in comparison with doxorubicin. METHODS: About 172 soft tissue sarcoma patients (mean age at diagnosis: 8.3 years), treated with epirubicin (median cumulative dose: 450 mg/m2) or doxorubicin (median cumulative dose: 240 mg/m2) within the high-risk group of the CWS-96 study, were examined in a prospective multicentre study. Heart function was analysed by echocardiography, measuring left-ventricular fractional shortening (FS). The median follow up was 27.7 months. RESULTS: Incidence of clinically manifest cardiomyopathy was 0% (0/60; 95% CI: 0-6.0%) in patients treated with epirubicin, and 0.9% (1/108; 95% CI: 0-5.1%) in patients treated with doxorubicin. A further three patients showed subclinical cardiomyopathy. There was no difference in FS between the two treatment arms. CONCLUSIONS: Cardiotoxicity was low in our study. For the short term, cardiotoxicity seems to be only a minor problem in patients treated with epirubicin as applied in this cohort.

[Soft tissue sarcoma in children and adolescents: experiences of the cooperative Soft Tissue Sarcoma Group Studies (CWS-81 - 96)]. / Weichteilsarkome im Kindes- und Jugendalter: Erfahrungen der kooperativen Weichteilsarkom-Studien (CWS-81 - 96).

The very heterogeneous group of paediatric soft tissue sarcomas account for approximately 7 % of all malignant childhood tumours. More than one half of all cases are rhabdomyosarcomas, some of the over 20 entities are very rare. The prognosis and biology of soft tissue sarcomas in children and adolescents vary greatly depending on histological subtype, the age of the patient, the primary site, the tumour size, tumour invasiveness and the extent of disease at diagnosis. Since 1981, 2918 children and adolescents with soft tissue sarcomas were treated prospectively according to the common treatment protocols of the Cooperative Soft Tissue Sarcoma Study Group (CWS-81 - 96). The known prognostic factors were used to develop a more and more detailed risk stratification. The multimodal treatment includes the use of surgery, chemotherapy and radiotherapy and should be planned by a multidisciplinary team. That way, an overall survival of nearly 70 % over all risk groups could be achieved.

Hearing function in soft tissue sarcoma patients after treatment with carboplatin: a report from the Late Effects Surveillance System.

The aim of this study was to analyse carboplatin-induced ototoxicity in a recent study trial. Twenty patients who had received carboplatin for the treatment of soft tissue sarcoma were investigated prospectively for ototoxicity in a multi-centre trial. Hearing function was tested by audiometry. All patients but one were treated with a cumulative dose of 1500 mg/m(2), the remaining with 500 mg/m(2). We evaluated the incidence and dependencies of hearing loss, and compared hearing thresholds to those of an untreated control group (n=60). Hearing thresholds in the carboplatin treated group were only marginally poorer compared with those of the control group. After carboplatin therapy no patient (0%; 95%-KI: 0-17%) had a hearing loss >20 dB. Hearing thresholds were not dependent on age, sex or cranial irradiation. We conclude that ototoxicity after carboplatin was low in our group of patients.

Is alveolar histotype a prognostic factor in paratesticular rhabdomyosarcoma? The experience of Italian and German Soft Tissue Sarcoma Cooperative Group.

PURPOSE: To ascertain whether alveolar histology retains its adverse prognostic role in the subset of paratesticular rhabdomyosarcoma (RMS) patients, generally characterized by a very good outcome. PATIENTS AND METHODS: Twenty pediatric patients were treated over a 25-year period using the protocols of the Italian and German Soft Tissue Sarcoma Cooperative Groups. Clinical characteristics at presentation were much the same as in non-alveolar patients. RESULTS: The proportion of patients with alveolar histotype (8%) in paratesticular site was lower than in the general RMS population (20-30%). With a median follow-up of 122 months, 5-year EFS and OS were 78 and 89%, respectively. CONCLUSION: Our data suggest a distinctly better clinical behavior of paratesticular alveolar RMS than when the disease occurs at other sites. These patients were more intensively treated than the embryonal cases, however, so-although a treatment intensity reduction may be desiderable-the idea of eliminating the alkylating agents (as in low-risk embryonal paratesticular RMS) must be considered with great caution.