International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2004
Comparative StudyThree-dimensional conformal vs. intensity-modulated radiotherapy in head-and-neck cancer patients: comparative analysis of dosimetric and technical parameters.
The use of intensity-modulated radiotherapy (IMRT) is now widely advocated for the treatment of head-and-neck cancers, to increase the therapeutic ratio of radiotherapy used as sole modality of treatment or in combination with chemotherapy. This report aims to summarize the technical and dosimetric factors to be taken into consideration to assess the respective advantages of the various high conformality treatments in radiotherapy, especially in the framework of quality assurance procedures. ⋯ Elective target volumes ranged from 530 to 1151 cm(3) with a mean of 780 +/- 141 cm(3). Boost volumes ranged from 248 to 832 cm(3) with a mean of 537 +/- 165 cm(3). Thirty-two dose plans were generated with static technique and 10 with dynamic. In the static mode, 6.8 +/- 3.4 fields were applied on average with 12.5 +/- 1.3 segments per field. In the static mode, 264 +/- 56 MU per Gy were erogated, whereas in the dynamic mode, 387 +/- 126 MU per Gy were erogated, to be compared to 147 +/- 20 computed for reference 3DCRT plans. For all target volumes in general, conformity was improved compared to 3DCRT (e.g. V(95) increased from 85% to 93% with p < 0.001, or equivalent uniform dose normalized to prescribed dose increased from 0.86 to 0.96 with p = 0.002). Irradiation of parotid glands or spinal cord improved, as well: For parotids, D(2/3V) reduced from 59 Gy to 41 Gy (p < 0.001). For spinal cord, D(max) reduced from about 40 Gy to about 30 Gy (p < 0.001).
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2004
Antisense MDM2 sensitizes prostate cancer cells to androgen deprivation, radiation, and the combination.
Antisense MDM2 (AS) sensitizes a variety of tumor cell types, including prostate cancer, to radiation and chemotherapy. We have previously described that AS enhances the apoptotic response to androgen deprivation (AD) and that this translates into a reduction in overall cell survival, as measured by clonogenic assay. Because AD + radiation (RT) is a key strategy for the treatment of men with high-risk prostate cancer, AS was tested for the ability to sensitize cells to the combination of AD+RT. ⋯ AS sensitizes cells to AD, RT, and AD+RT and shows promise in the treatment of the full range of patients with prostate cancer. AS has the potential to sensitize the primary tumor to AD+RT and metastasis to AD.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2004
Clinical TrialResults of carbon ion radiotherapy in 152 patients.
This study summarizes the experience with raster scanned carbon ion radiation therapy (RT) at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany since 1997. ⋯ Carbon ion therapy is safe with respect to toxicity and offers high local control rates for skull base tumors such as chordomas, low-grade chondrosarcomas, and unfavorable adenoid cystic carcinomas.