Revisiting the role of radiotherapy in the treatment of neuroblastoma 4S: 30 years of institutional experience and systematic review

Background and purpose

Neuroblastoma 4S is a rare subtype of metastatic neuroblastoma found in children younger than 12 months, characterized by liver, skin, or bone marrow metastases. While the prognosis for patients is generally favorable, rapid progression of liver metastases can lead to life-threatening organ insufficiency. In such cases, immediate treatment with chemotherapy or radiotherapy is necessary. Given the recent decline in radiotherapy utilization, this study aims to reassess its role, evaluating its effectiveness and toxicity.

Materials and methods

We conducted a systematic review and an institutional retrospective analysis to assess the use of radiotherapy for hepatomegaly in patients with neuroblastoma 4S. The study included data from 164 patients from the literature and 16 patients from our institutional cohort. We extracted and analyzed data on short- and long-term outcomes, as well as reports of radiotherapy-induced toxicity.

Results

Our institutional data showed that 81 % of patients responded to low-dose radiotherapy administered at a median dose of 450 cGy in three fractions, resulting in liver shrinkage and symptom resolution. Based on the systematic review, 1-year survival rate was 80 %, while 5-year survival rate was 75 %. No serious toxicity was observed with the current low-dose radiotherapy; however, one case of induced secondary malignancy was reported.

Conclusion

Radiation therapy is an effective treatment modality for hepatomegaly in patients with neuroblastoma 4S, with a success rate of about 80 %. Despite being administered to infants, a low dose of 450-600 cGy does not result in toxicity related to the kidneys, liver, or posture defects.

Current and future potential distributions of three Dracaena Vand. ex L. species under two contrasting climate change scenarios in Africa

Forest undergrowth plants are tightly connected with the shady and humid conditions that occur under the canopy of tropical forests. However, projected climatic changes, such as decreasing precipitation and increasing temperature, negatively affect understory environments by promoting light-demanding and drought-tolerant species. Therefore, we aimed to quantify the influence of climate change on the spatial distribution of three selected forest undergrowth plants, Dracaena Vand. ex L. species, D. afromontana Mildbr., D. camerooniana Baker, and D. surculosa Lindl., simultaneously creating the most comprehensive location database for these species to date. A total of 1,223 herbarium records originating from tropical Africa and derived from 93 herbarium collections worldwide have been gathered, validated, and entered into a database. Species-specific Maxent species distribution models (SDMs) based on 11 bioclimatic variables from the WorldClim database were developed for the species. HadGEM2-ES projections of bioclimatic variables in two contrasting representative concentration pathways (RCPs), RCP2.6 and RCP8.5, were used to quantify the changes in future potential species distribution. D. afromontana is mostly sensitive to temperature in the wettest month, and its potential geographical range is predicted to decrease (up to -63.7% at RCP8.5). Optimum conditions for D. camerooniana are low diurnal temperature range (6-8°C) and precipitation in the wettest season exceeding 750 mm. The extent of this species will also decrease, but not as drastically as that of D. afromontana. D. surculosa prefers high precipitation in the coldest months. Its potential habitat area is predicted to increase in the future and to expand toward the east. This study developed SDMs and estimated current and future (year 2050) potential distributions of the forest undergrowth Dracaena species. D. afromontana, naturally associated with mountainous plant communities, was the most sensitive to predicted climate warming. In contrast, D. surculosa was predicted to extend its geographical range, regardless of the climate change scenario.

Dataset and GIS toolbox for modeling potential tree belt functions

The dataset and toolbox presented in this article are related to the research article entitled "Modeling potential tree belt functions in rural landscapes using a new GIS tool" (Nowak and Pędziwiatr, 2018) [1]. The dataset (spatially referenced) is used as input for all the five analysis modules described in the related article. The dataset contains vector and raster data, which cover north-west part of the Gen. Dezydery Chłapowski Landscape Park in Poland. Moreover, the present work shows the result (a vector layer) of using the TBM toolbox within ArcGIS (ESRI) software. The Tree Belt Modeling (TBM toolbox) code and internal structure can be fully accessed, and are available for further modification and incorporation of tools. The toolbox is available for download as supplementary material to this online article.

Modeling potential tree belt functions in rural landscapes using a new GIS tool

The increasing human pressure on the environment requires effective protection activities. One way to stop the degradation of natural resources is the presence of woody vegetation networks, mainly linear in character, called linear woody features, greenways or tree belts. These objects, thanks to the many natural and economic functions they serve, enable the realization of sustainable development policy. To properly design a greenway network, the natural conditions and degree of environmental degradation in a given area must first be evaluated. Based on these data, it is possible to determine appropriate afforestation needs. To evaluate the ability of a given area to meet the requirements of greenway functions, we propose a new computer modeling system - a tree belt modeling (TBM). TBM defines the availability of tree belt functions in the planned network and is one of preparation stages in the design of an optimal greenway structure. In this work, to analyze the studied area potential, application of a cadastral dataset was proposed. Thanks to this approach, the obtained results may be related to specific plot borders, which is optimal for greenway construction. To automatize the process of analysis, the TBM was implemented into an ArcGIS toolbox. The result of using this toolbox is a tree belt functions geodatabase. This database contains information about the available functions in the analyzed lines that are potential sites for afforestation. This solution, both at the methodological and technological levels, may significantly increase the effectiveness of greenway planning and thus contribute to more effective activities for sustainable development.

Second brain tumors following central nervous system radiotherapy in childhood

OBJECTIVE

The second tumour (ST) occurrence is a relatively uncommon late complication of radiotherapy but represents one of the most significant issues, especially in childhood oncology. We describe our experience with patients who developed second brain neoplasm following cranial irradiation in childhood.

METHODS

We identified nine patients who received radiotherapy owing to central nervous system tumour in childhood and subsequently developed the second brain tumour. The full clinical and radiological documentation and histopathological reports were reviewed. Risk factors such as age at irradiation, latency period to ST diagnosis, radiotherapy doses and volumes and other therapy methods were evaluated. We correlated the ST location with the three levels of irradiation dose (high, >40 Gy; medium, 25-40 Gy; and low <25 Gy).

RESULTS

Five meningiomas and four gliomas occurred as the ST after the mean time of 11.7 years after radiotherapy. The average age of children during irradiation was 4.6 years. The shorter latency time to the ST induction was found in children treated with chemotherapy (9 years vs 17.2 years). Seven STs developed in the area of high and moderate dose (>25 Gy), only two low-grade gliomas appeared in the low-dose region.

CONCLUSION

Our data suggest that the STs usually develop in the brain tissues that received doses >25 Gy in patients irradiated at a young age.

ADVANCES IN KNOWLEDGE

The low-dose volume seems not to be so significant for second brain neoplasm induction. Therefore, the modern intensity-modulated radiotherapy technique could be safely applied in paediatric patients.

Spinal cord ependymoma in children--results of postoperative radiotherapy

PURPOSE

A retrospective study was performed to evaluate the results of postoperative radiation therapy of spinal cord ependymoma in children.

METHODS AND MATERIALS

Between 1984 and 2005, 28 children with spinal cord ependymoma were treated with radiotherapy, after surgery and in three cases after chemotherapy as well. Median age at diagnosis was 13.3 years (range from 4.7 to 16.2 years). Ependymoma myxopapillare was identified in 13, ependymoma in 12 and anaplastic ependymoma in 3 cases.

RESULTS

With a median follow-up of 8.7 years (range from 3 to 25 years) 22 patients were alive. The overall survival rate of 2, 5 and 10 years was 93%, 85% and 77% respectively, whereas progression free survival rate was 82%, 74% and 74% respectively. Patients with myxopapillary ependymoma had significantly better 5-year overall survival rate 100% than those with other histopathological types 60% (p=0.016). There were 2 relapse incidences observed among 13 patients with myxopapillary ependymoma, both underwent repeated surgery and reirradiation. In the group of 20 patients with gross total resection the overall 5-year survival rate was 100% in comparison with 62.5% with partial surgery, but it did not achieve statistical significance.

CONCLUSIONS

The histological type of ependymoma myxopapillary was a statistical significant favourable prognostic factor. The gross total resection with adjuvant radiotherapy allows obtaining a high total survival rate.

Craniospinal radiotherapy in children: Electron- or photon-based technique of spinal irradiation

BACKGROUND

The prone position and electron-based technique for craniospinal irradiation (CSI) have been standard in our department for many years. But this immobilization is difficult for the anaesthesiologist to gain airway access. The increasing number of children treated under anaesthesia led us to reconsider our technique.

AIM

The purpose of this study is to report our new photon-based technique for CSI which could be applied in both the supine and the prone position and to compare this technique with our electron-based technique.

MATERIALS AND METHODS

Between November 2007 and May 2008, 11 children with brain tumours were treated in the prone position with CSI. For 9 patients two treatment plans were created: the first one using photons and the second one using electron beams for spinal irradiation. We prepared seven 3D-conformal photon plans and four forward planned segmented field plans. We compared 20 treatment plans in terms of target dose homogeneity and sparing of organs at risk.

RESULTS

In segmented field plans better dose homogeneity in the thecal sac volume was achieved than in electron-based plans. Regarding doses in organs at risk, in photon-based plans we obtained a lower dose in the thyroid but a higher one in the heart and liver.

CONCLUSIONS

Our technique can be applied in both the supine and prone position and it seems to be more feasible and precise than the electron technique. However, more homogeneous target coverage and higher precision of dose delivery for photons are obtained at the cost of slightly higher doses to the heart and liver.