RESUMEN
BACKGROUND: The purpose of this study is to evaluate practice patterns and outcomes between intensity-modulated radiation therapy (IMRT) and 3D-conformal radiation (3D-CRT) in early stage glottic cancer. METHODS: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify and compare patient and disease profiles, mortality, and toxicity in patients with T1-2 larynx cancer undergoing definitive radiation (RT). RESULTS: A total of 1520 patients underwent definitive radiation with 3D-CRT (n = 1309) or IMRT (n = 211). Non-white race, those with a Charlson Comorbidity Index ≥2, T2 disease, and those treated at community practices were more likely to undergo IMRT. Rates of IMRT increased from 2006 to 2015, while relative rates of 3D-CRT decreased. Two-year CSS was superior with 3D-CRT (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.22-0.65; p < 0.001). There was no difference in OS between 3D-CRT and IMRT (p = 0.119). CONCLUSIONS: Patients receiving 3D-CRT had improved CSS compared to IMRT with no difference in OS.
Asunto(s)
Neoplasias Laríngeas , Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Anciano , Glotis , Humanos , Neoplasias Laríngeas/radioterapia , Medicare , Dosificación Radioterapéutica , Estados Unidos/epidemiologíaRESUMEN
Medical dosimetry is an important component in training of radiation therapist, yet it is not easy for student to understand the principle of treatment planning and to be familiar with the relationship of the clinical target volume (CTV), planned target volume (PTV), and the nearby organs at risk (OARs) by just imagination. This study is conducted to evaluate whether using VERT in teaching medical dosimetry can help student to improve their learning experience. Students of cohort 2015 and 2016 were taught under TPS mode and TPS + VERT mode respectively. Direct comparison was conducted through self-evaluation survey, between two groups of students, in terms of their understanding of the concept of medical dosimetry and their level of confidence in completing different types of plans after the course. Both groups of students were able to understand the concept of medical dosimetry and able to complete 3D conformal plans after taking the course. Though, the students received TPS mode reported that they had lower level of confidence in completing the planning and required longer time for self-study and practice compared to the students who received the TPS + VERT mode. This study demonstrated that including VERT into medical dosimetry education can improve students' learning experience, by improving their self-confidence, as well as reducing time required for their self-study and practice.
Asunto(s)
Educación Médica , Oncología por Radiación , Humanos , Aprendizaje , Órganos en Riesgo , Oncología por Radiación/educación , Planificación de la Radioterapia Asistida por ComputadorRESUMEN
Breast boost irradiation is an integral component to the standard of care for early staged breast cancer. The use of reduced tangents is common for deep seating tumor bed; however, reduced tangents result in non-conformal plans delivering prescription dose to large volumes of breast tissue. To improve conformity, a novel technique of integrating a single conformal arc with reduced tangents has been developed. With this technique, a conformal arc was placed between a pair of reduced tangents to better conform the prescription dose to the target volume. This new technique improves the conformity but was also shown to potentially increase max dose to nearby critical structures, such as the heart, due to exit dose from the arc. This tangent and arc technique has been implemented at our clinic in cases where the exit dose is not critical to the heart.
Asunto(s)
Neoplasias de la Mama/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Conformacional/métodos , Femenino , Humanos , Estudios RetrospectivosRESUMEN
PURPOSE: To evaluate influences associated with radiation treatment planning obtained with the patient breathing freely. MATERIAL AND METHODS: We compared reduction or elimination of planning target volume (PTV) margins with 2-D conventional plan with inclusion of PTV margins associated with breathing with 3-D conformal therapy. The respiratory non gated 3-D conformal treatment plans were compared with respiratory gated conventional 2-D plans in 4 patients with hepatocellular carcinomas. Isodose distribution, dose statistics, and dose volume histogram (DVH) of PTVs were used to evaluate differences between respiratory gated conventional 2-D plans and respiratory non gated 3-D conformal treatment plans. In addition, the risk of radiation exposure of surrounding normal liver and organs are evaluated by means of DVH and normal tissue complication probabilities (NTCPs). RESULTS: The vertical movement of liver ranged 2-3 cm in all patients. We found no difference between respiratory gated 2-D plans and 3-D conformal treatment plans with the patients breathing freely. Treatment planning using DVH analysis of PTV and the normal liver was used for all patients. DVH and calculated NTCP showed no difference in respiratory gated 2-D plans and respiratory non gated 3-D conformal treatment plans. CONCLUSION: Respiratory gated radiation therapy was very important in hepatic tumors because radiation induced hepatitis was dependent on remaining normal liver volume. Further investigational studies for respiratory gated radiation treatment combined with 3-D conformal treatment are required.