PURPOSE: To determine the feasibility and benefits of optimized magnetic resonance imaging (MRI)-guided brachytherapy (BT) for cancer of the cervix. METHODS AND MATERIALS: A total of 20 patients with International Federation of Gynecology and Obstetrics Stage IB-IV cervical cancer had an MRI-compatible intrauterine BT applicator inserted after external beam radiotherapy. MRI scans were acquired, and the gross tumor volume at diagnosis and at BT, the high-risk (HR) and intermediate-risk clinical target volume (CTV), and rectal, sigmoid, and bladder walls were delineated. Pulsed-dose-rate BT was planned and delivered in a conventional manner. Optimized MRI-based plans were developed and compared with the conventional plans. RESULTS: The HR CTV and intermediate-risk CTV were adequately treated (the percentage of volume treated to >or=100% of the intended dose was >95%) in 70% and 85% of the patients with the conventional plans, respectively, and in 75% and 95% of the patients with the optimized plans, respectively. The minimal dose to the contiguous 2 cm(3) of the rectal, sigmoid, and bladder wall volume was 16 +/- 6.2, 25 +/- 8.7, and 31 +/- 9.2 Gy, respectively. With MRI-guided BT optimization, it was possible to maintain coverage of the HR-CTV and reduce the dose to the normal tissues, especially in patients with small tumors at BT. In these patients, the HR percentage of volume treated to >or=100% of the intended dose approached 100% in all cases, and the minimal dose to the contiguous 2-cm(3) of the rectum, sigmoid, and bladder was 12-32% less than with conventional BT planning. CONCLUSION: MRI-based BT for cervical cancer has the potential to optimize primary tumor dosimetry and reduce the dose to critical normal tissues, particularly in patients with small tumors.
PURPOSE: To determine the feasibility and benefits of optimized magnetic resonance imaging (MRI)-guided brachytherapy (BT) for cancer of the cervix. METHODS AND MATERIALS: A total of 20 patients with International Federation of Gynecology and Obstetrics Stage IB-IV cervical cancer had an MRI-compatible intrauterine BT applicator inserted after external beam radiotherapy. MRI scans were acquired, and the gross tumor volume at diagnosis and at BT, the high-risk (HR) and intermediate-risk clinical target volume (CTV), and rectal, sigmoid, and bladder walls were delineated. Pulsed-dose-rate BT was planned and delivered in a conventional manner. Optimized MRI-based plans were developed and compared with the conventional plans. RESULTS: The HR CTV and intermediate-risk CTV were adequately treated (the percentage of volume treated to >or=100% of the intended dose was >95%) in 70% and 85% of the patients with the conventional plans, respectively, and in 75% and 95% of the patients with the optimized plans, respectively. The minimal dose to the contiguous 2 cm(3) of the rectal, sigmoid, and bladder wall volume was 16 +/- 6.2, 25 +/- 8.7, and 31 +/- 9.2 Gy, respectively. With MRI-guided BT optimization, it was possible to maintain coverage of the HR-CTV and reduce the dose to the normal tissues, especially in patients with small tumors at BT. In these patients, the HR percentage of volume treated to >or=100% of the intended dose approached 100% in all cases, and the minimal dose to the contiguous 2-cm(3) of the rectum, sigmoid, and bladder was 12-32% less than with conventional BT planning. CONCLUSION: MRI-based BT for cervical cancer has the potential to optimize primary tumor dosimetry and reduce the dose to critical normal tissues, particularly in patients with small tumors.
Authors: Karem R Domínguez Hernández; Alberto A Aguilar Lasserre; Rubén Posada Gómez; José A Palet Guzmán; Blanca E González Sánchez Journal: Comput Math Methods Med Date: 2013-04-18 Impact factor: 2.238
Authors: Johannes C A Dimopoulos; Peter Petrow; Kari Tanderup; Primoz Petric; Daniel Berger; Christian Kirisits; Erik M Pedersen; Erik van Limbergen; Christine Haie-Meder; Richard Pötter Journal: Radiother Oncol Date: 2012-01-30 Impact factor: 6.280
Authors: James W Anderson; Junyi Xia; Ryan T Flynn; Joseph M Modrick; Sudershan K Bhatia; Geraldine M Jacobson; Yusung Kim Journal: J Contemp Brachytherapy Date: 2013-06-28