Development and characterization of polymorphic microsatellite markers in taro (Colocasia esculenta)

Microsatellite-containing sequences were isolated from enriched genomic libraries of taro (Colocasia esculenta (L.) Schott). The sequencing of 269 clones yielded 77 inserts containing repeat motifs. The majority of these (81.7%) were dinucleotide or trinucleotide repeats. The GT/CA repeat motif was the most common, accounting for 42% of all repeat types. From a total of 43 primer pairs designed, 41 produced markers within the expected size range. Sixteen (39%) were polymorphic when screened against a restricted set of taro genotypes from Southeast Asia and Oceania, with an average of 3.2 alleles detected on each locus. These markers represent a useful resource for taro germplasm management, genome mapping, and marker-assisted selection

Childhood cancer treatment optimization: In rhabdomyosarcoma and supportive care

This thesis covers two subjects investigating optimization of cancer cure: prevention and treatment of central venous catheter related complications and improvement of local treatment in head and neck rhabdomyosarcoma survivors. Central venous catheters are indispensable in the modern day treatment of children with cancer. However, these catheters also impose an increased risk of catheter-related infections or -thrombosis. In this thesis the results of two systematic Cochrane reviews are presented, investigating catheter-related complications. Furthermore, we present the results of the Aristocaths study: a randomized controlled multi-center trial investigating prophylactic 70% ethanol locks in pediatric oncology patients with central venous catheters. In a second chapter, the prevalence of asymptomatic and symptomatic venous thrombo-embolic events in the Aristocaths cohort are presented. In the majority of head and neck rhabdomyosarcoma patients radiotherapy is needed to achieve and maintain local control. Radiotherapy, however, is known to cause damage to surrounding tissue and may cause growth abnormalities and impaired function. Therefore an innovative local treatment approach was developed in the Emma Children’s Hospital, aiming to reduce radiotherapy induced adverse events: Ablative surgery, MOld technique after loading brachytherapy, and surgical REconstruction (AMORE). In the first chapter the image-based response classification, qualifying for local treatment, is evaluated. In the following chapter we evaluate potential failure patterns of surgery and brachytherapy in patients treated for orbital rhabdomyosarcoma. In the last chapters adverse events following local treatment in head and neck rhabdomyosarcoma are described and a comparison is made between the AMORE approach and the international standard: external beam radiotherapy

The role of I-131-metaiodobenzylguanidine (MIBG) therapy in unresectable and compromising localised neuroblastoma

In patients with localised neuroblastoma without adverse genetic aberrations, observational treatment is justified. Therapy is required when organ or respiratory functions have become compromised. As the outcome is good, side effects of treatment should be prevented. The aim of this retrospective study was to evaluate response and outcome in patients treated with (131)I-metaiodobenzylguanidine (MIBG) for unresectable localised neuroblastoma, with compromised organ functions. Patients with localised neuroblastoma [median age 1.6 years (0-5.5 years)] diagnosed between 1989 and 2008 were included in this retrospective study (n = 21). Primary tumours were unresectable and there was a compromised organ or respiratory function. Diagnosis and staging were performed according to the International Neuroblastoma Staging System. Fixed doses of (131)I-MIBG therapy (50-200 mCi) were given. The median number of infusions was two (range one to seven). Response was graded according to the International Neuroblastoma Response Criteria. Of the 21 patients, 14 did not need any chemotherapy. Patients were treated with (131)I-MIBG therapy and, in most cases, with additional surgery and/or chemotherapy. Sixteen achieved complete response (CR), three very good partial response (VGPR), one partial response (PR) and one progressive disease (PD). Two patients died of PD after having achieved CR initially and due to surgical complications a few months after resection. Ten-year overall survival and event-free survival were 90.5 %. The median follow-up was 8.5 years (range 0.4-19.6 years). (131)I-MIBG therapy is an effective treatment modality for unresectable localised neuroblastoma with compromised organ functions. However, this was a small and heterogeneous cohort and further studies are neede

An overview of radiological manifestations of acquired dental developmental disturbances in paediatric head and neck cancer survivors

Objectives: In paediatric cancer survivors treated with chemotherapy and radiotherapy therapy, late effects on dental development are quite common. Oral radiologists are not familiar with the radiographic images of these specific dental consequences of chemotherapy and radiotherapy. With the goal of educating colleagues, to raise awareness of the needs of survivors, and to identify directions for future research, we present dental radiographs of survivors treated for head and neck rhabdomyosarcoma with chemotherapy and radiotherapy. Also, based on the survivors reviewed, a radiographic inventory of commonly found late dental developmental effects seen in conjunction with treatment is presented. Methods: Panoramic radiographic findings of five illustrative cases are presented, from a group of 42 survivors of head and neck rhabdomyosarcoma treated at the Academic Medical Center Amsterdam, The Netherlands over the past 25 years. Results: Five cases showing dental developmental disorders are presented. These cases show an association of the location of the radiation field and the developmental stage of the teeth with the severity of the effect on dental development. We also report an inventory of severe and moderate effects of chemotherapy and radiotherapy on the development of molars and anterior teeth. conclusions: This paper presents five cases and a radiographic inventory to illustrate disturbances of dental development associated with chemotherapy and radiotherapy in children. Medical and dental professionals involved in the treatment of cancer survivors are relatively unaware of the dental consequences of radiation therapy and the age dependency of specific regional effects. These effects can be severe, with great impact on quality of life. Further research in this area could help improve planning of radiation therapy for children, potentially preventing or limiting dental or maxillofacial sequelae

AMORE treatment as salvage treatment in children and young adults with relapsed head-neck rhabdomyosarcoma

Background and purpose: Survival after relapse of head and neck rhabdomyosarcoma (HNRMS) after prior external beam radiotherapy (EBRT) is poor, since options for adequate local treatment are often lacking. In this study we describe our experience with salvage AMORE in patients with relapsed HNRMS after prior EBRT. Materials and methods: Patients with relapsed HNRMS after prior EBRT in which salvage AMORE treatment was considered feasible were analysed; this includes patients with parameningeal, head and neck non-parameningeal and orbital localization. AMORE treatment consisted of Ablative surgery, MOuld technique brachytherapy and surgical REconstruction. Results: In total 18 patients received salvage AMORE treatment; nine patients had relapsed parameningeal (PM) RMS, two patients had relapsed head and neck non-parameningeal RMS (HN-nonPM) and seven patients had relapsed orbital RMS. Local control rate was 67% and 5-year overall survival was 54% (95% confidence interval: 31–78%); 3/9 patients with PM RMS, 0/2 patients with HN-nonPM RMS and 6/7 patients with orbital RMS were alive after a median follow-up of 8.6 years. One patient with PM RMS survived more than 5 years after which he died from a secondary cancer. Six patients developed a local relapse (of which one patient also developed a distant metastasis) and two patients developed distant metastases. Conclusions: Salvage AMORE treatment is a feasible and effective local therapy approach even after prior EBRT. Since salvage AMORE treatment is sometimes the only curative option in patient with relapsed HNRMS, we encourage physicians to consider salvage AMORE treatment for patients with relapsed HNRMS after prior EBRT