Results of a multi-institutional benchmark test for cranial CT/MR image registration

PURPOSE: Variability in computed tomography/magnetic resonance imaging (CT/MR) cranial image registration was assessed using a benchmark case developed by the Quality Assurance Review Center to credential institutions for participation in Children\u27s Oncology Group Protocol ACNS0221 for treatment of pediatric low-grade glioma. METHODS AND MATERIALS: Two DICOM image sets, an MR and a CT of the same patient, were provided to each institution. A small target in the posterior occipital lobe was readily visible on two slices of the MR scan and not visible on the CT scan. Each institution registered the two scans using whatever software system and method it ordinarily uses for such a case. The target volume was then contoured on the two MR slices, and the coordinates of the center of the corresponding target in the CT coordinate system were reported. The average of all submissions was used to determine the true center of the target. RESULTS: Results are reported from 51 submissions representing 45 institutions and 11 software systems. The average error in the position of the center of the target was 1.8 mm (1 standard deviation = 2.2 mm). The least variation in position was in the lateral direction. Manual registration gave significantly better results than did automatic registration (p = 0.02). CONCLUSION: When MR and CT scans of the head are registered with currently available software, there is inherent uncertainty of approximately 2 mm (1 standard deviation), which should be considered when defining planning target volumes and PRVs for organs at risk on registered image sets

Long-term results of low-dose-rate interstitial-intracavitary brachytherapy in the treatment of carcinoma of the cervix.

PurposeBrachytherapy plays a major role in the treatment of patients with carcinoma of the cervix. However, routine intracavitary brachytherapy may not be feasible or adequate to treat locally advanced disease. The purpose of this retrospective study (spanning a 20-year period) was to determine the outcome of interstitial low-dose-rate brachytherapy in the treatment of bulky or locally advanced cervical cancer. The long-term survival and safety of this technique were evaluated, along with its impact on local and locoregional control, disease-free survival, and complications.Methods and materialsA total of 185 previously untreated patients with cervical cancer were treated between 1977 and 1997. According to the International Federation of Gynecology and Obstetrics classification, 21 patients had Stage IB (barrel), 77 Stage II, 77 Stage III, and 10 Stage IV disease. All patients were treated by a combination of external megavoltage irradiation to the pelvis to a dose of 5040 cGy followed by interstitial-intracavitary implants to a dose of 40-50 Gy to the implanted volume in two applications.ResultsClinical local control was achieved in 152 (82%) of the 185 patients. A 5-year disease-free survival rate of 65%, 67%, 49%, and 17% was achieved for patients with Stage IB, II, III, and IV disease, respectively. Eighteen (10%) of the 185 patients developed Radiation Therapy Oncology Group Grade 3 or 4 late complications.ConclusionPatients with locally advanced cervical cancer, or with distorted anatomy, may be treated adequately with interstitial brachytherapy to achieve excellent locoregional control and a reasonable chance of cure with acceptable morbidity

Long-term results of low-dose-rate interstitial-intracavitary brachytherapy in the treatment of carcinoma of the cervix.

PurposeBrachytherapy plays a major role in the treatment of patients with carcinoma of the cervix. However, routine intracavitary brachytherapy may not be feasible or adequate to treat locally advanced disease. The purpose of this retrospective study (spanning a 20-year period) was to determine the outcome of interstitial low-dose-rate brachytherapy in the treatment of bulky or locally advanced cervical cancer. The long-term survival and safety of this technique were evaluated, along with its impact on local and locoregional control, disease-free survival, and complications.Methods and materialsA total of 185 previously untreated patients with cervical cancer were treated between 1977 and 1997. According to the International Federation of Gynecology and Obstetrics classification, 21 patients had Stage IB (barrel), 77 Stage II, 77 Stage III, and 10 Stage IV disease. All patients were treated by a combination of external megavoltage irradiation to the pelvis to a dose of 5040 cGy followed by interstitial-intracavitary implants to a dose of 40-50 Gy to the implanted volume in two applications.ResultsClinical local control was achieved in 152 (82%) of the 185 patients. A 5-year disease-free survival rate of 65%, 67%, 49%, and 17% was achieved for patients with Stage IB, II, III, and IV disease, respectively. Eighteen (10%) of the 185 patients developed Radiation Therapy Oncology Group Grade 3 or 4 late complications.ConclusionPatients with locally advanced cervical cancer, or with distorted anatomy, may be treated adequately with interstitial brachytherapy to achieve excellent locoregional control and a reasonable chance of cure with acceptable morbidity

Conformal Radiation Therapy for Pediatric Patients with Low-Grade Glioma: Results from the Children\u27s Oncology Group Phase 2 Study ACNS0221

Purpose: To determine the rate of marginal relapse, progression-free survival (PFS), and overall survival (OS) in patients with pediatric low-grade glioma (PLGG) treated with conformal radiation therapy (CRT) with a clinical target volume (CTV) margin of 5 mm in the Children\u27s Oncology Group trial ACNS0221. Methods and Materials: Patients aged 3 to 21 years with unresectable progressive, recurrent, or residual PLGG were eligible for this study. Patients younger than 10 years were required to have received at least 1 chemotherapy course. Patients with neurofibromatosis type I were not eligible. All patients underwent magnetic resonance imaging-based planning and received 54 Gy CRT in 30 fractions with a 5-mm CTV margin. Results: Of 85 eligible patients (median age, 13.6 years) treated between March 2006 and December 2010, 14 were younger than 10 years and 36 received prior chemotherapy. Sixty-six had pilocytic astrocytoma, 15 had other histologic subtypes, and 4 had unbiopsied chiasmatic lesions. Events included 23 relapses (19 central, 4 distant, and no marginal) and 7 deaths. At a median follow-up of 5.15 years, 5-year PFS was 71% ± 6% and OS was 93% ± 4%. Male sex (P =.068) and large tumor size (P =.050) trended toward significance for association with decreased PFS. Age, histology, tumor location, time between diagnosis and study entry, and MIB-1 status were not associated with PFS. OS was negatively associated with male sex (P =.064), non-pilocytic astrocytoma histology (P =.010), and large tumor size (P =.0089). Conclusions: For patients with PLGG, CRT with a CTV margin of 5 mm yields an acceptable PFS and does not lead to a high rate of marginal relapse

Children\u27s Oncology Group Phase III Trial of Reduced-Dose and Reduced-Volume Radiotherapy With Chemotherapy for Newly Diagnosed Average-Risk Medulloblastoma

PURPOSE: Children with average-risk medulloblastoma (MB) experience survival rates of ≥ 80% at the expense of adverse consequences of treatment. Efforts to mitigate these effects include deintensification of craniospinal irradiation (CSI) dose and volume. METHODS: ACNS0331 (ClinicalTrials.gov identifier: NCT00085735) randomly assigned patients age 3-21 years with average-risk MB to receive posterior fossa radiation therapy (PFRT) or involved field radiation therapy (IFRT) following CSI. Young children (3-7 years) were also randomly assigned to receive standard-dose CSI (SDCSI; 23.4 Gy) or low-dose CSI (LDCSI; 18 Gy). Post hoc molecular classification and mutational analysis contextualized outcomes according to known biologic subgroups (Wingless, Sonic Hedgehog, group 3, and group 4) and genetic biomarkers. Neurocognitive changes and ototoxicity were monitored over time. RESULTS: Five hundred forty-nine patients were enrolled on study, of which 464 were eligible and evaluable to compare PFRT versus IFRT and 226 for SDCSI versus LDCSI. The five-year event-free survival (EFS) was 82.5% (95% CI, 77.2 to 87.8) and 80.5% (95% CI, 75.2 to 85.8) for the IFRT and PFRT regimens, respectively, and 71.4% (95% CI, 62.8 to 80) and 82.9% (95% CI, 75.6 to 90.2) for the LDCSI and SDCSI regimens, respectively. IFRT was not inferior to PFRT (hazard ratio, 0.97; 94% upper CI, 1.32). LDCSI was inferior to SDCSI (hazard ratio, 1.67%; 80% upper CI, 2.10). Improved EFS was observed in patients with Sonic Hedgehog MB who were randomly assigned to the IFRT arm (P = .018). Patients with group 4 MB receiving LDCSI exhibited inferior EFS (P = .047). Children receiving SDCSI exhibited greater late declines in IQ (estimate = 5.87; P = .021). CONCLUSION: Reducing the radiation boost volume in average-risk MB is safe and does not compromise survival. Reducing CSI dose in young children with average-risk MB results in inferior outcomes, possibly in a subgroup-dependent manner, but is associated with better neurocognitive outcome. Molecularly informed patient selection warrants further exploration for children with MB to be considered for late-effect sparing approaches