A Pilot Study of Low-Dose Craniospinal Irradiation in Patients With Newly Diagnosed Average-Risk Medulloblastoma

Feasibility and Safety of Implementing Volumetric Arc Therapy (VMAT) for Pediatric Craniospinal Irradiation in a Low-Middle-Income Region: The Nigerian Experience

Purpose

Volumetric modulated arc therapy (VMAT) is a relatively new treatment technique in sub-Saharan Africa. Although craniospinal irradiation (CSI) in the pediatric population has been practiced in Nigeria for many years, the use of VMAT to deliver this treatment is previously undocumented. We reviewed the first set of patients to undergo CSI at a cancer center in Nigeria, detailing the treatment technique, the progress experienced, dose statistics achieved, treatment toxicities, and cancer outcomes to date.

Methods and Materials

This was a prospective case series of 5 children with histologically diagnosed cancers requiring CSI whose parents consented to the study. They were recruited at evaluation and followed through the process of their therapy. Toxicity was monitored at weekly review appointments using the Common Terminology Criteria for Adverse Events version 5.0. Follow-up of the children will continue in the long-term effects clinic.

Results

Five patients with a median age of 6 were recruited. Diagnoses were intracranial germ cell tumor (n = 2), medulloblastoma (n = 1), pineoblastoma (n = 1), and ependymoma (n = 1). For all patients, a dose of 36.0 Gy in 1.8 Gy daily fractions was prescribed to the entire neuraxis. A subsequent boost of 18 Gy (n = 4) to 19.8 Gy (n = 1) in 10 daily fractions to the primary tumor bed (n = 2) and posterior fossa (n = 2) was delivered. Four patients had chemotherapy before, during, or after radiation therapy. No patient experienced grade 3 or greater toxicity.

Conclusions

Our results indicate great progress has been made in the delivery of CSI in Nigeria, demonstrating tolerable acute side effects using VMAT. This series suggests the feasibility of implementing VMAT technology in low- or middle-income countries. Additional follow-up will be needed to determine whether survival rates and chronic toxicity rates are similar to those reported in the literature.

Comparison of Acute Hematological Adverse Reactions Induced by Craniospinal Irradiation With Intensity-Modulated Radiotherapy and Conventional Radiotherapy

Background

With the update of equipment, the hospital base of this study began to adopt craniospinal irradiation (CSI) intensity-modulated radiotherapy (IMRT) in May 2018 to replace the traditional CSI conventional radiotherapy (CRT) technology. The purpose of this study was designed to compare the differences in acute hematological adverse reactions induced by CSI-IMRT and CSI-CRT.

Methods

The clinical data and hematological data of 102 patients with central nervous system malignant tumors who underwent CSI treatment at the 900th Hospital of Joint Logistics Support Force of PLA from January 2008 to August 2022 were analyzed retrospectively. The patients included 63 men and 39 women, aged 3 to 56 years old. On the basis of the radiotherapy technique used, the patients were divided into the CSI-IMRT group (38 cases) and CSI-CRT group (64 cases). Acute hematological adverse reactions during radiotherapy were compared between the two groups according to the Common Terminology Criteria for Adverse Events version 4.0. The Mann-Whitney U test was used to compare the measurement data, and the χ² test was used to compare the count data.

Results

No significant difference was found between the CSI-IMRT group and the CSI-CRT group in terms of sex, histopathological type, tumor location, spinal cord invasion, surgery, and the Eastern Cooperative Oncology Group score (χ² = 0.004 to 6.213; all P > .05). No significant difference was found in onset time of myelosuppression (11 days (interquartile range [IQR]: 7 to 14; minimum [min] to maximum [max]: 0 to 26) vs 8 days (IQR: 7 to 15; min to max: 3 to 29)) and nadir time of myelosuppression (21 days (IQR: 18 to 25; min to max: 12 to 35) vs 22 days (IQR: 15 to 25; min to max: 12 to 36)) between the CSI-IMRT group and the CSI-CRT group (Z = -0.856, -0.248; all P > .05). There were no significant differences in the incidence of decreased white blood cell counts (WBC), platelet counts, and hemoglobin concentration between the CSI-IMRT group and the CSI-CRT group, 86.8% (33/38) vs 78.1% (50/64), 57.9% (22/38) vs 42.2% (27/64), 57.9% (22/38) vs 53.1% (34/64); χ² = 1.195, 2.357, 0.219; all P > .05. There were no significant differences in the incidence of decreased WBC, platelet counts, and hemoglobin concentration (severe myelosuppression) in grades III and IV, 23.7% (9/38) vs 21.9% (14/64), 7.9% (3/38) vs 3.1% (2/64), 5.3% (2/38) vs 9.4% (6/64); χ² = 0.045, 1.164, 0.558; all P > .05.

Conclusions

There was no significant difference in the incidence of myelosuppression and severe myelosuppression (grade III or above) induced by CSI-IMRT and CSI-CRT. CSI-IMRT is worthy of further clinical application.

Long-term outcomes and late toxicity of adult medulloblastoma treated with combined modality therapy: A contemporary single-institution experience

BACKGROUND

Medulloblastoma (MB) is a rare central nervous system malignancy of adults, with limited contemporary studies to define treatment guidelines and expected late toxicity.

METHODS

A single-center, retrospective study was conducted of patients age ≥18 years from 1997-2019 with MB and who were treated with postoperative radiotherapy. Late toxicity was defined as a minimum of 18 months from diagnosis. Overall survival (OS) and progression-free survival (PFS) were characterized using Kaplan-Meier and Cox regression analyses.

RESULTS

Fifty-nine patients met criteria, with median age of 25 years (range 18-62 y) and median follow-up of 6.5 years (range 0.7-23.1 y). At diagnosis, 68% were standard-risk, 88% Chang M0, and 22% with anaplastic histology. Gross total resection was achieved in 75%; median craniospinal irradiation dose was 30.6 Gy (relative biological effectiveness [RBE]), median total dose was 54.0 Gy (RBE), 80% received proton radiotherapy; 81% received chemotherapy. 5 year PFS and OS were 86.5% and 95.8%, respectively; 10 year PFS and OS were 83.9% and 90.7%, respectively. Anaplastic histology was associated with worse PFS (P = .04). Among eight recurrences, 25% presented after 5 years. Most common grade ≥2 late toxicities were anxiety/depressive symptoms (30%), motor dysfunction (25%), and ototoxicity (22%). Higher posterior fossa radiation dose was associated with increased risk of late toxicity, including worse cognitive dysfunction (P = .05).

CONCLUSIONS

Adults with MB have favorable survival outcomes, but late failures and toxicity are not uncommon. Better understanding of prognostic factors, possibly from molecular subtyping, may help to define more personalized treatments for patients with high risk of recurrence and long-term treatment sequelae.