Clinical analysis of intracranial germinoma's craniospinal irradiation using helical tomotherapy

The top 100 most cited articles in helical tomotherapy: a scoping review

Objective

The purpose of this scoping review was to explore the top 100 most cited articles in helical tomotherapy (HT) through bibliometric analysis and visualization tools, help researchers comprehensively understand the research hotspots of HT, and provide clear and intuitive network visualization.

Methods

The Web of Science Core Collection and the search strategy of "Title (TI)=(tomotherapy)" were used to search for articles related to HT as of 27 May 2023. The top 100 most cited articles were obtained by sorting "citations: highest first". From these top 100 most cited articles, the following information was extracted: journals, years and months, countries, authors, types of tumor treated, and topics. The VOSviewer software was introduced for visualizing all the articles related to HT.

Results

The top 100 most cited articles in HT were published between 1999 and 2019. The citation counts of these articles ranges from 326 to 45, with a total of 8,422 citations at the time of searching. The index of citations per year (CPY) ranges from 22.32 to 2.45. These articles originated from 17 countries, with most publications from the United States (n=50), followed by Canada (n=12), Italy (n=10), Germany (n=7) and Belgium (n=5). The International Journal of Radiation Oncology, Biology, Physics published the highest number of articles (n=31), followed by Radiotherapy and Oncology (n=20), Medical Physics (n=13) and Strahlentherapie und Onkologie (n=12). In terms of specific tumor types, head and neck cancer (n=15) is the most common disease, followed by cancers with complex target structures (n=14), breast cancer (n=12), prostate cancer (n=10) and lung cancer (n=8). The most common research topics also include dosimetric comparison (n = 44), quality assurance (n = 12) and Megavoltage CT (n = 8).

Conclusion

This scoping review provides a comprehensive list of the 100 most cited articles in HT. This analysis offers valuable insights into the current research directions of HT that can be utilized by researchers, clinicians, and policy-makers.

Helical tomotherapy in patients with leptomeningeal metastases

Purpose

Leptomeningeal metastasis (LM) is an increasingly common complication of late-stage systemic cancer, for which there is no standard treatment. We analyzed outcome and toxicity in patients with LM undergoing craniospinal irradiation via helical tomotherapy (HT-CSI) at our institution.

Patients and methods

The charts of 15 patients diagnosed with LM and undergoing HT-CSI between 2006 and 2014 were retrospectively assessed. Main neoplasms included breast cancer, lung cancer, and lymphoma. All patients presented with cranial neuropathy due to LM. Follow-up was performed regularly. Survival analysis was performed by the Kaplan–Meier method, and prognostic factors were tested using the COX-regression model.

Results

Median survival by cancer type was 6 (breast cancer), 1 (lung cancer), and 2 months (lymphoma), respectively. Median overall survival and relapse-free survival were calculated to be between 2 and 3 months. Six- and 12-month survival was 30% (95% CI 0.08–0.5) and 20% (95% CI 0.05–0.4), respectively. Symptom palliation occurred in 53% of patients in general, but in 67% of breast cancer patients, in particular. Patients with lung cancer experienced no improvement. Most common acute treatment-related toxicity at different levels were hematological toxicity, multiple cranial neuropathy, fatigue, infections, nausea, and headache.

Conclusion

HT-CSI can help meet the challenge of treating patients with LM, especially because it can palliate symptoms and improve neurological functions. One-year survival remains as disappointing as before.

Radiotherapy for Adult Medulloblastoma: Evaluation of Helical Tomotherapy, Volumetric Intensity Modulated Arc Therapy, and Three-Dimensional Conformal Radiotherapy and the Results of Helical Tomotherapy Therapy

Introduction

All adult medulloblastoma (AMB) patients should be treated with craniospinal irradiation (CSI) postoperatively. Because of the long irradiation range, multiple radiation fields must be designed for conventional radiotherapy technology. CSI can be completed in only one session with helical tomotherapy (HT). We evaluated the dose of HT, volumetric intensity modulated arc therapy (VMAT), and three-dimensional conformal radiotherapy (3D-CRT) of AMB and the results of 5 cases of AMB treated with HT.

Methods

Complete craniospinal and posterior cranial fossa irradiation with HT, VMAT, and 3D-CRT and dose evaluation were performed. And results of 5 cases of AMB treated with HT were evaluated.

Results

A large volume of tissue was exposed to low dose radiation in the organs at risk (OAR), while a small volume was exposed to high dose radiation with HT. The conformity and uniformity of the targets were good with HT and VMAT, and the volume of targets exposed to high dose with VMAT was larger than that of HT. The uniformity of 3D-CRT was also good, but the dose conformity was poor. The main toxicity was hematologic toxicity, without 4th-degree bone marrow suppression. There was 3rd-degree inhibition in the white blood cells, hemoglobin, and platelets. The three female patients suffered menstrual disorders during the course of radiation. Two female patients with heavy menstruation suffered 3rd-degree anemia inhibition, and 2 patients suffered amenorrhea after radiotherapy. Although menstrual cycle was normal, the third patient was not pregnant.

Conclusion

CSI with HT is convenient for clinical practice, and the side effects are mild. With good conformity and uniformity, VMAT can also be used for selection in CSI. For poor conformity, 3D-CRT should not be the priority selection for CSI. In female patients, the ovaries should be protected.

Craniospinal irradiation using helical tomotherapy for central nervous system tumors

The aim of this study was to describe early and late toxicity, survival and local control in 45 patients with primary brain tumors treated with helical tomotherapy craniospinal irradiation (HT-CSI). From 2006 to 2014, 45 patients with central nervous system malignancies were treated with HT-CSI. The most common tumors were medulloblastoma in 20 patients, ependymoma in 10 patients, intracranial germinoma (ICG) in 7 patients, and primitive neuroectodermal tumor in 4 patients. Hematological toxicity during treatment included leukopenia Grades 1-4 (6.7%, 33.3%, 37.8% and 17.8%, respectively), anemia Grades 1-4 (44.4%, 22.2%, 22.2% and 0%, respectively) and thrombocytopenia Grades 1-4 (51.1%, 15.6%, 15.6% and 6.7%, respectively). The most common acute toxicities were nausea, vomiting, fatigue, loss of appetite, alopecia and neurotoxicity. No Grade 3 or higher late toxicity occurred. The overall 3- and 5-year survival rates were 80% and 70%, respectively. Survival for the main tumor entities included 3- and 5-year survival rates of 80% and 70%, respectively, for patients with medulloblastoma, 70% for both in patients with ependymoma, and 100% for both in patients with ICG. Relapse occurred in 11 patients (24.4%): 10 with local and 1 with multifocal relapse. One patient experienced a secondary cancer. M-status and the results of the re-evaluation at the end of treatment were significantly related to survival. Survival after HT-CSI was in line with the existing literature, and acute treatment-induced toxicity resolved quickly. Compared with conventional radiotherapy, HT offers benefits such as avoiding gaps and junctions, sparing organs, and better and more homogeneous dose distribution and coverage of the target volume.

Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging

OBJECTIVE

To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system (CNS) germ cell tumors (GCTs).

METHODS

DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic (ROC) curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.

RESULTS

A significant elevation in transfer constant (K(trans)) and extravascular extracellular space (Ve) (P=0.000), as well as a significant reduction in rate constant (Kep) (P=0.000) was observed in tumors. K(trans), relative K(trans), and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K(trans) showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value (PPV) of 95.8%, and negative predictive value (NPV) of 100%.

CONCLUSIONS

Relative K(trans) appeared promising in predicting tumor response to radiation therapy (RT). It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.

Intracranial multiple germ cell tumors: a case report and review of literature

Intracranial multiple germ cell tumors (GCTs) are rare. In this article, we reported a case of intracranial multiple GCTs in an 18-year-old boy with symptoms of psychosis for 8 months also. Tumors in the pineal, sellar region, corpus callosum, bilateral lateral ventricles and fourth ventricle were confirmed by enhanced magnetic resonance imaging (MRI) and stereotactic biopsy. Immunohistochemical analysis results demonstrated that the tumor cells were positive for CD117 and placental alkaline phosphatase (PLAP). The patient was treated by radiotherapy and the prescribed radiation doses were 18 Gy. After near 24 months of follow-up, no local recurrence and distant metastasis has been found.