International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2004
Stereotactic conformal radiotherapy in patients with growth hormone-secreting pituitary adenoma.
To evaluate the reduction of hormonal overproduction and side effects as well as survival rates after fractionated stereotactic conformal radiotherapy (FSRT) and radiosurgery in patients with growth hormone (GH)-secreting pituitary adenoma. ⋯ Stereotactic conformal radiotherapy is effective and safe in the treatment of GH-secreting pituitary adenoma to reduce hormonal overproduction and to improve local control. It is an alternative option to surgery especially for patients at high risk of surgical complications due to comorbidity.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2004
Factors predictive of having four or more positive axillary lymph nodes in patients with positive sentinel lymph nodes: implications for selection of radiation fields.
The optimal design of radiation fields for patients with positive sentinel lymph nodes (SLNs) who do not undergo axillary dissection is unknown. We have previously shown that modified breast tangent fields can include most axillary Level I-II lymph nodes. We have also reported that irradiation of the axillary apex/supraclavicular fossa is indicated for patients with four or more positive axillary lymph nodes. To determine the optimal arrangement for patients with positive SLNs, we studied what factors predicted for having four or more positive lymph nodes. ⋯ It is reasonable to treat with modified tangents fields that include most axillary Level I-II nodes for patients with one positive SLN who do not undergo axillary dissection if drainage is seen on lymphoscintigraphy and no LVSI is present. This approach is also reasonable for patients treated with neoadjuvant chemotherapy who have Stage II disease, no LVSI, and only one positive SLN. The remaining patients have a greater risk of having four or more positive lymph nodes, and, therefore, the high axilla/supraclavicular fossa should also be included in the radiation fields.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2004
Daily ultrasound-based image-guided targeting for radiotherapy of upper abdominal malignancies.
Development and implementation of a strategy to use a stereotactic ultrasound (US)-based image-guided targeting device (BAT) to align intensity-modulated radiotherapy (IMRT) target volumes accurately in the upper abdomen. Because the outlines of such targets may be poorly visualized by US, we present a method that uses adjacent vascular guidance structures as surrogates for the target position. We assessed the potential for improvement of daily repositioning and the feasibility of daily application. ⋯ Daily US-guided BAT targeting for patients with upper abdominal tumors was feasible in the vast majority of attempted setups. This method of US-based image-guided tumor targeting has been successfully implemented in clinical routine. The observed improved daily repositioning accuracy might allow for individualized reduction of safety margins and optional dose escalation. Compared with the established application of the BAT device for prostate radiotherapy, in which the target can be directly visualized, the TV in the present study was predominantly positioned relative to guidance vascular structures in close anatomic relation. We perceived an enormous potential in improved and individualized patient positioning for fractionated radiotherapy and also for stereotactic extracranial radiotherapy and radiosurgery, especially for tumors of the liver and pancreas.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2004
Influence of radiation therapy parameters on outcome in children treated with radiation therapy for localized parameningeal rhabdomyosarcoma in Intergroup Rhabdomyosarcoma Study Group trials II through IV.
To evaluate the impact of radiation treatment parameters on cancer control outcomes for children with parameningeal rhabdomyosarcoma (PM-RMS) treated on Intergroup Rhabdomyosarcoma Study Group protocols II through IV (including IRS-IV pilot). ⋯ The availability of cross-sectional diagnostic images (CT or MRI) has improved detection of ICE. Starting radiation therapy within 2 weeks of diagnosis for patients with signs of meningeal impingement was associated with lower rates of local failure. When no signs of meningeal impingement were present, delay of radiation therapy for more than 10 weeks did not impact local failure rates. Whole brain radiation therapy is unnecessary in PM-RMS. A dose of at least 47.5 Gy seems to be associated with lower rates of local failure, especially when tumor diameter is > or =5 cm.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2004
3D CT-based high-dose-rate breast brachytherapy implants: treatment planning and quality assurance.
Although accelerated partial breast irradiation (APBI) as the sole radiation modality after lumpectomy has shown promising results for select breast cancer patients, published experiences thus far have provided limited information on treatment planning methodology and quality assurance measures. A novel three-dimensional computed tomography (CT)-based treatment planning method for accurate delineation and geometric coverage of the target volume is presented. A correlation between treatment volume and irradiation time has also been studied for quality assurance purposes. ⋯ CT-based treatment planning allowed excellent visualization of the lumpectomy cavity and normal structures, thereby improving target volume delineation and optimal coverage, relative to conventional orthogonal film dosimetry. Using the Manchester volume implant table calculated irradiation time can be used as quality assurance for the HDR computed time. Thus dosimetric quality assurance and adequate target volume coverage can be concurrently confirmed, allowing prospective evaluation and optimization of implants.