The observed variance between predicted and measured radiation dose in breast and prostate patients utilizing an in vivo dosimeter.

PURPOSE: Report the results of using a permanently implantable dosimeter in radiation therapy: determine specific adverse events, degree of migration, and acquire dose measurements during treatment to determine difference between expected and measured dose. METHODS AND MATERIALS: The Dose Verification System is a wireless, permanently implantable metal-oxide semiconductor field-effect transistor dosimeter using a bidirectional antenna for power and data transfer. The study cohort includes 36 breast (33 patients received two devices) and 29 prostate (21 patients received two devices) cancer patients. A total of 1,783 and 1,749 daily dose measurements were obtained on breast and prostate patients, respectively. The measurements were compared with the planned expected dose. Biweekly computed tomography scans were obtained to evaluate migration and the National Cancer Institute's Common Toxicity Criteria, version 3, was used to evaluate adverse events. RESULTS: Only Grade I/II adverse events of pain and bleeding were noted. There were only four instances of dosimeter migration of >5 mm from known factors. A deviation of > or =7% in cumulative dose was noted in 7 of 36 (19%) for breast cancer patients. In prostate cancer patients, a > or =7% deviation was noted in 6 of 29 (21%) and 8 of 19 (42%) during initial and boost irradiation, respectively. The two patterns of dose deviation were random and systematic. Some causes for these differences could involve organ movement, patient movement, or treatment plan considerations. CONCLUSIONS: The Dose Verification System was not associated with significant adverse events or migration. The dosimeter can measure dose in situ on a daily basis. The accuracy and utility of the dose verification system complements current image-guided radiation therapy and intensity-modulated radiation therapy techniques.

POG 8625: a randomized trial comparing chemotherapy with chemoradiotherapy for children and adolescents with Stages I, IIA, IIIA1 Hodgkin Disease: a report from the Children's Oncology Group.

To determine if 6 courses of chemotherapy alone could achieve the same or better outcome than 4 courses of chemotherapy followed by radiation therapy (chemoradiotherapy) in pediatric and adolescent patients with Hodgkin disease. Children < or =21 years old with biopsy-proven, pathologically staged I, IIA, or IIIA1 Hodgkin disease were randomly assigned 6 courses of alternating nitrogen mustard, oncovin, prednisone, and procarbazine/doxorubicin, bleomycin, vinblastine, and dacarbazine (treatment 1) or 4 courses of alternating nitrogen mustard, oncovin, prednisone, and procarbazine/doxorubicin, bleomycin, vinblastine, and dacarbazine +2550 cGy involved-field radiotherapy (treatment 2). The complete response rate was 89%, with a complete response and partial response rate of 99.4%. There was no statistically significant difference in event-free survival (EFS) or overall survival between arms. The EFS for those who achieved an early complete response was significantly higher than for those who did not. For pediatric patients with asymptomatic low-stage and intermediate-stage Hodgkin disease, chemotherapy and chemoradiotherapy both resulted in 3-year EFS of approximately 90% and statistically indistinguishable 8-year EFS and overall survival, without significant long-term toxicity. Early response to therapy was associated with higher EFS, a concept that has led to the Children's Oncology Group paradigm of response-based risk-adapted therapy for pediatric Hodgkin disease.