Novel technique for craniospinal radiotherapy with patient supine

A simple procedure to plan, verify and implement craniospinal irradiation（CSI） with patients supine is presented. Treatment is conducted with a single posterior spinal field abutting two lateral cranial fields. The opposed lateral fields are half-blocked and the inferior line is perpendicular. The posterior field uses some fixed field parameters so that the cephalad edge of the posterior field is coplanar with the caudal edges of the lateral fields and it is independent of the height of the couch. A steel-shot ball is used to measure the size of overlap or gap at the junction using portal images of an electron portal image device or portal films. The results of analyzing the portal images show that the errors of the junction are within ± 1 mm. The dose-volume histograms （DVHs）show that there are not unbearable hot or cold spots in the clinic target volumes （CTVs）. Supine craniospinal treatment is a reliable and convenient alternative to treatment in the prone position and avoids the technical difficulties of the latter. The use of fixed field geometry greatly facilitates treatment planning and effectively reduces the amount of time of setup, verification and treatment.

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

Objective： To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation （CSI） using helical tomotherapy （HT） system in our center. Methods： Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. M1 of the patients＇ CSI used the HT system. The total doses were 27-36 Gy/15-20 F （1.5-2 Gy per fraction）, and total local doses were 46-60 Gy/30-50 F （5 fractions per week）. M1 female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months （range, 5-67 months）. The SPSS19.0 software was used, and the overall survival （OS） was calculated using the Kaplan-Meier method. Results： Among 17 patients with assessable tumors, 9 cases （52.9%） were CR, 7 cases （41.2%） were PR, and 1 case （5.9%） was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively. Conclusions： For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk （ORA） and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.

The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques

Introduction: In medulloblastoma patients craniospinal irradiation is an important element the treatment. Our study aimed to evaluate the effect of absorbed dose to organs at risk using the hybrid intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) for craniospinal irradiation (CSI) in average risk medulloblastoma patients. Materials and Methods: In this study, thirteen medulloblastoma patients were included. The prescribed total dose to the planning target volume (PTV) was 23, 40 Gy in 13 fractions. Two radiotherapy techniques, three dimensional conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (IMRT) were used to treat these patients. The coverage of the Target was evaluated using the D mean, D95%, D2%, D98% and V95%. Other parameters were also compared such as Integral dose (ID), Homogeneity index (HI) and doses to the organs at risk (OARs). Results: There was no significant difference in the mean dose received by the PTV-Brain or the dose received by 95% and 98% of PTV volume using the two techniques. For PTV-Spine, the percentage volume receiving 95% of the total dose increased significantly in the hybrid IMRT technique compared to the conformal technique. So, hybrid IMRT plan achieved the best coverage for PTV spine. Lower dose for OAR was delivered by 3DCRT, except the heart and thyroid, hybrid IMRT achieved better sparing. All plans resulted in the same dose homogeneity index (DHI) for PTV-Brain. For PTV-Spine, hybrid IMRT technique achieved better dose homogeneity compared to 3DCRT technique (1.09 vs. 1.12;p > 0.05). Conclusions: hybrid IMRT technique can be realized on conformal technique because it achieved better dose coverage for the (PTV) and organ at risk (OAR). 3DCRT reduced mean dose to most OARS, except the heart and thyroid. Therefore, the hybrid IMRT technique may be a CSI treatment alternative to 3DCRT.

Recombinant human vascular endostatin injection to synchronize craniospinal radiotherapy for the treatment of recurrent medulloblastoma in children:A retrospective clinical study

Objective Medulloblastoma(MB)is the most common primary central nervous system malignancy in children.Nonetheless,there is no standard treatment for recurrent MB.The purpose of this study was to investigate the clinical value and toxicity of recombinant human endostatin injection(Endostar~?)combined with craniospinal radiotherapy for the treatment of recurrent MB in children.Methods This study retrospectively analyzed 13 patients with recurrent MB aged 5–18 years.Endostar?7.5 mg/m~2/d was synchronized during craniospinal radiotherapy for 7 children with a portable micro uniform speed infusion pump.Endostar~?was applied 3 days prior to the initiation of radiotherapy.The drug was in continuous use for 7 days.Similarly,the withdrawal of the drug took place over 7 days.This represented a cycle.During radiotherapy,the application was repeated until the end of radiotherapy(experimental group).In the other 6 cases,only craniospinal radiotherapy was used(control group).Results The complete remission rate was 71.4%in the experimental group and 16.7%in the control group.The median progression-free survival(PFS)was 14 months(95%CI:0.0–29.60)and 19 months(95%CI:0.0–39.53)in the experimental and control groups,respectively.The median overall survival(OS)was 19 months(95%CI:0.0–38.20)and 23 months(95%CI:2.47–43.53)in the experimental and control groups,respectively.The most common adverse events included grade 1 thrombocytopenia(7.7%),grade 3 neutropenia(38.5%),and grade 1 anemia(30.8%).Conclusion Endostar~?synchronizing craniospinal radiotherapy significantly improved the complete response rate of children with recurrent MB.It did not increase the side effects of radiation therapy.However,it did not improve the PFS or OS.

Treatment of pediatric average-risk medulloblastoma using craniospinal irradiation less than 2500 cGy and chemotherapy: single center experience in Korea

Background:Although craniospinal irradiation (CSI) of 2340 cGy plus tumor booster with chemotherapy have been established as a standard treatment of childhood average-risk (AvR) medulloblastoma (MBL) in Western counties,there are a few recent reports in outcomes ofAvR MBL using this strategy in Korean and other Asian children.We investigated the outcome of the Korean children with AvR MBL who were treated with CSI <2500 cGy and chemotherapy.Methods:Between January 2001 and December 2010,clinical characteristics and outcomes of 42 patients who were diagnosed with AvR MBL postoperatively and treated with radiation including CSI <2500 cGy and chemotherapy in Seoul National University Children's Hospital were analyzed.Results:Their median age was 9 years (range:3-18.8),and 29 were male.Histological subtypes were classic type in 28 patients,nodular/desmoplastic in 7,and large cell/anaplastic (LCA) in 7.All the patients received adjuvant radiotherapy (CSI with median 2340 cGy and booster) and multiagent chemotherapy as the first-fine treatment.With a median follow-up of 54 months,12 patients experienced relapse or progression of the tumor.The 3-and 5-year disease-free survival (DFS) rates were 78.0%±6.5% and 75.0%±6.9%,respectively,and overall survival (OS) rates were 85.3%±5.6% and 76.8%±6.9%,respectively.The LCA subtype was associated with poorer DFS (P=0.023) and OS (P=0.008),compared with non-LCA subtypes.Conclusion:The outcomes of children and adolescents with AvR MBL treated with radiation including CSI <2500 cGy and chemotherapy,are compatible to those in Western countries;however,the LCA subtype has a poor outcome with this strategy.

Treatment Outcome and Prognostic Factors for Pediatric Medulloblastoma Patients: The Egyptian National Cancer Institute Experience

Purpose: To evaluate treatment outcomes and prognostic factors of pediatric Medulloblastoma (MB) patients treated by adjuvant post-operative riskadapted radiotherapy (RT) and chemotherapy (CT). Patients and Methods: A retrospective analysis was conducted based on medical records of pediatric patients with pathologically confirmed MB treated between 2006 and 2013 at the National cancer Institute (NCI), Egypt. Various patients’ and disease characteristics, treatment details and outcome data were reviewed. Results: Fifty patients’ records were included in the analysis with a median age of 6 years at diagnosis (range 3 - 18). According to the Chang staging system;38%, 44%, 4%, and 14% were M0, M1, M2, and M3, respectively. All patients underwent primary surgery;gross total resection (with no residual) in 38%, near total resection (with residual ≤1.5 cm2) in 8%, subtotal resection (with residual > 1.5 cm2) in 34%, and 20% had only biopsy. All patients were treated by riskadapted craniospinal irradiation (CSI);high-risk patients were treated by CSI 36 Gy/20 fractions over 4 weeks followed by posterior fossa (PF) boost 18 Gy/10 fractions over 2 weeks (180 cGy per fraction), while standard-risk patients were treated by CSI 23.4 Gy/13 fractions over 2 and half weeks followed by PF boost 30.6 Gy/17 fractions over 3 and half weeks. Median overall treatment time (OTT) was 52 days. All patients received adjuvant CT;47 patients (94%) received concomitant chemo radiotherapy (CCRT), while 4 patients (8%) only received neoadjuvant CT (NB: only one patient received all neoadjuvant, concomitant and adjuvant CT). With a median follow up time of 32.5 months, ranging from 6 to 104 months, the whole group estimates of the overall survival (OS) at 1, 3, and 5 years were 83%, 70%, and 64%, respectively, while, the progression-free survival (PFS) rates at 1, 3, and 5 years were 79%, 62%, and 57% respectively. Four patients relapsed. Neural-axis was the commonest site of relapse (3 patients). Both risk groups were equally represented in relapsed patients (2 standard risk & 2 high risk patients) and relapse took place within 2 years. In univariate analysis, performance status,extent of surgery, and post-operative residual tumor size were significant prognostic factors for OS. On the other hand, factors which affected the PFS included gender, extent of surgery, and post-operative residual tumor. Conclusion: Neural-axis relapse was the commonest site of relapse for pediatric MB patients. Extent of surgical resection, post-operative residual tumor, and gender are powerful prognostic factors. Maximal safe resection is the standard surgical approach for MB patients to achieve cure.