Conformal Radiation Therapy for Ependymoma at Age ≤3 Years: A 25-Year Experience.

PURPOSE: Adjuvant radiation therapy (RT) affects survival after surgery for young children (age <3 years) diagnosed with intracranial ependymoma. Conformal photon RT promised to spare normal tissue and was introduced more than 25 years ago to improve outcomes for these vulnerable patients. Long-term results for those first treated with conformal methods provide valuable information and serve as a comparison against newer methods. METHODS AND MATERIALS: Between 1997 and 2018, 101 patients <3.1-years-old were treated with conformal and intensity modulated photon therapy after definitive surgery for intracranial ependymoma. The median age at RT was 2.1 years and the time from diagnosis to the start of RT was 10 weeks. The extent of resection was gross-total in 82%, and 38% underwent more than 1 attempt at resection. The total prescribed dose was 54 to 59.4 Gy at 1.8 Gy per fraction. RESULTS: The 10-year event-free and overall survivals were 58.5% ± 5.0% and 72.6% ± 4.5%, respectively, with a median follow-up of 18.4 years (range, 4.2-23.3 years). Tumor progression occurred in 34 patients with a median time of 1.6 years. Death occurred in 34 patients from ependymoma (n = 24), secondary malignancy (n = 6), necrosis (n = 2), shunt failure (n = 1), and anaphylactic reaction (n = 1). Twenty-three patients developed a secondary tumor including 6 cases of fatal high-grade glioma. Of the surviving cohort and those ≥18 years old, 98% obtained a high school diploma, 64% had a current driver's license, 89% were students or employed full or part time, 32% were living independently, and 70% received higher education or training. CONCLUSIONS: Long-term results of children treated using photon conformal RT after surgery demonstrate that adjuvant RT resulted in long-term disease control and functional independence. These results point to the need for new treatment strategies to improve tumor control and provide investigators hope that newer RT methods will further reduce complications.

Limited surgery and conformal photon radiation therapy for pediatric craniopharyngioma: long-term results from the RT1 protocol.

BACKGROUND: Our aim was to estimate long-term disease control and complications after conformal radiation therapy (CRT) in children and adolescents with craniopharyngioma. MATERIALS AND METHODS: Pediatric patients with craniopharyngioma (n = 101) were enrolled on or treated according to a phase II single institutional protocol from 1998. Surgery was individualized, and CRT (54Gy) was administered using a 1.0 cm or 0.5 cm clinical target volume margin. Patients were followed for 10 years by serial MR imaging and MR angiography and a battery of tests to measure the effects of treatment. RESULTS: Twenty patients had tumor progression. Twelve patients who had tumor progression died due to tumor (n = 6) or complications related to tumor or treatment (n = 6). With a median follow-up of 14.94 years for survivors, the 10 year estimates (±SE) of progression-free survival (PFS), event-free survival (EFS), and overall survival (OS) were 78.84% ± 4.10%, 77.12% ± 4.19%, and 96.02% ± 1.95%, respectively. OS, EFS, and PFS were significantly associated with race, shunt status, and tumor volume. The 10 year cumulative incidence (±SE) of the secondary tumor (1.99% ± 1.40%), secondary malignant tumor (1.0% ± 1.0%), necrosis (1.98% ± 1.39%), vasculopathy (8.47% ± 2.90%), and permanent neurologic deficits (8.28% ± 3.37%) were estimated by competing risk analysis. Three patients required revascularization surgery. Salvage therapy was successful in 13 patients using surgery and radiosurgery. CONCLUSIONS: Limited surgery and CRT using photons results in excellent tumor control. Tumor control and the incidence and severity of complications are associated with host, tumor, and treatment factors.

Endocrine outcomes after limited surgery and conformal photon radiation therapy for pediatric craniopharyngioma: Long-term results from the RT1 protocol.

BACKGROUND: To estimate the incidence of endocrinopathy in children and adolescents with craniopharyngioma after treatment with photon-based conformal and intensity-modulated radiation therapy (CRT). METHODS: One hundred one pediatric patients were enrolled on a phase II single-institution protocol beginning in 1998 (n = 76) or followed a similar non-protocol treatment plan (n = 25). Surgery was individualized. CRT (54 Gy) was administered using a 1.0-cm or ≤0.5-cm clinical target volume margin. Patients underwent baseline and serial evaluation of the hypothalamic-pituitary axis. RESULTS: The 10-year cumulative incidence (CI) of growth hormone deficiency (GHD) was 68.42% (±11.27) for black patients and 94.23% (±3.57) for white patients (P = .0286). The CI of thyroid-stimulating hormone deficiency (TSHD) was 70.94% (±8.44) at 10 years for non-shunted patients and 91.67% (±10.40) at 6 years for shunted patients (P = .0260). The CI of TSHD was 100% (±14.29) at 4 years for those with diabetes insipidus (DI) and 71.36% (±8.86) at 10 years for those without DI (P = .0008). The 10-year CI of adrenocortical hormone deficiency was 70.00% (±16.15) for those with DI and 48.39% (±9.19) for those without DI (P = .0080). The 10-year CI of LH/FSH deficiency was 43.33% (±9.32) age <7 years, 61.29% (±9.11) aged 7-10 years, and 78.95% (±6.38) age ≥10 years (P < .0001). BMI was significantly greater prior to CRT in white patients with DI (P = .0004) and preexisting GHD (P = .0275). CONCLUSIONS: Hormone deficiencies are common in pediatric patients with craniopharyngioma and are associated with host, tumor, and treatment factors. Understanding the incidence and time to onset may facilitate intervention and patient selection for treatment.

Location as Destiny: Identifying Geospatial Disparities in Radiation Treatment Interruption by Neighborhood, Race, and Insurance.

PURPOSE: Radiation therapy interruption (RTI) worsens cancer outcomes. Our purpose was to benchmark and map RTI across a region in the United States with known cancer outcome disparities. METHODS AND MATERIALS: All radiation therapy (RT) treatments at our academic center were cataloged. Major RTI was defined as ≥5 unplanned RT appointment cancellations. Univariate and multivariable logistic and linear regression analyses identified associated factors. Major RTI was mapped by patient residence. A 2-sided P value <.0001 was considered statistically significant. RESULTS: Between 2015 and 2017, a total of 3754 patients received RT, of whom 3744 were eligible for analysis: 962 patients (25.8%) had ≥2 RT interruptions and 337 patients (9%) had major RTI. Disparities in major RTI were seen across Medicaid versus commercial/Medicare insurance (22.5% vs 7.2%; P < .0001), low versus high predicted income (13.0% vs 5.9%; P < .0001), Black versus White race (12.0% vs 6.6%; P < .0001), and urban versus suburban treatment location (12.0% vs 6.3%; P < .0001). On multivariable analysis, increased odds of major RTI were seen for Medicaid patients (odds ratio [OR], 3.35; 95% confidence interval [CI], 2.25-5.00; P < .0001) versus those with commercial/Medicare insurance and for head and neck (OR, 3.74; 95% CI, 2.56-5.46; P < .0001), gynecologic (OR, 3.28; 95% CI, 2.09-5.15; P < .0001), and lung cancers (OR, 3.12; 95% CI, 1.96-4.97; P < .0001) compared with breast cancer. Major RTI was mapped to urban, majority Black, low-income neighborhoods and to rural, majority White, low-income regions. CONCLUSIONS: Radiation treatment interruption disproportionately affects financially and socially vulnerable patient populations and maps to high-poverty neighborhoods. Geospatial mapping affords an opportunity to correlate RT access on a neighborhood level to inform potential intervention strategies.