International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2012
Metabolic response of lymph nodes immediately after RT is related with survival outcome of patients with pelvic node-positive cervical cancer using consecutive [18F]fluorodeoxyglucose-positron emission tomography/computed tomography.
To evaluate the metabolic response of uterine cervix and pelvic lymph nodes (LNs) using consecutive 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) immediately after RT and to correlate survival outcome with the metabolic response. ⋯ The results showed a significant correlation between survival outcome and the interim metabolic response of pelvic LNs. CMR of nodal lesion on inter-RT PET/CT had excellent overall survival, disease-free survival and distant metastasis-free survival rates. This suggested that PET/CT immediately after RT can be a useful tool for the evaluation of the interim response of the LNs and identify a subset of patients with a high risk of recurrence and poor survival in patients with cervical cancer with initial positive LNs.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2012
A three-isocenter jagged-junction IMRT approach for craniospinal irradiation without beam edge matching for field junctions.
Traditionally craniospinal irradiation treats the central nervous system using two or three adjacent field sets. We propose a technique using a three-isocenter intensity-modulated radiotherapy (IMRT) plan (jagged-junction IMRT) which overcomes problems associated with field junctions and beam edge matching and improves planning and treatment setup efficiencies with homogenous target dose distribution. ⋯ Jagged-junction IMRT planning provided good dose homogeneity and conformity to the target while maintaining a low dose to organs at risk. Results from jagged-junction IMRT plans were better than or equivalent to those from the conventional technique. Jagged-junction IMRT optimization smoothly distributed dose in the junction between field sets. Because there was no beam matching, this treatment technique is less likely to produce hot or cold spots at the junction, in contrast to conventional techniques. The planning process is also simplified as only one IMRT plan is required for the entire target volume.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2012
What is the optimal treatment of large brain metastases? An argument for a multidisciplinary approach.
Single-modality treatment of large brain metastases (>2 cm) with whole-brain irradiation, stereotactic radiosurgery (SRS) alone, or surgery alone is not effective, with local failure (LF) rates of 50% to 90%. Our goal was to improve local control (LC) by using multimodality therapy of surgery and adjuvant SRS targeting the resection cavity. ⋯ Surgery and adjuvant resection cavity SRS yields excellent LC of large brain metastases. Compared with other multimodality treatment options, this approach allows patients to avoid or delay whole-brain irradiation without compromising LC.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2012
Comparative StudyIntensity modulated proton and photon therapy for early prostate cancer with or without transperineal injection of a polyethylen glycol spacer: a treatment planning comparison study.
Rectal toxicity is a serious adverse effect in early-stage prostate cancer patients treated with curative radiation therapy (RT). Injecting a spacer between Denonvilliers' fascia increases the distance between the prostate and the anterior rectal wall and may thus decrease the rectal radiation-induced toxicity. We assessed the dosimetric impact of this spacer with advanced delivery RT techniques, including intensity modulated RT (IMRT), volumetric modulated arc therapy (VMAT), and intensity modulated proton beam RT (IMPT). ⋯ Regardless of the radiation technique, a substantial decrease of rectal dose was observed after spacer injection for curative RT to the prostate.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2012
Evaluation of rotational errors in treatment setup of stereotactic body radiation therapy of liver cancer.
To evaluate the dosimetric impact of rotational setup errors in stereotactic body radiotherapy (SBRT) treatment of liver tumors and to investigate whether translational shifts can compensate for rotation. ⋯ Actual rotational setup errors in SBRT for liver tumors are relatively small in magnitude and are unlikely to affect GTV coverage significantly. Translational corrections can be optimized to compensate for rotational setup errors. However, caution regarding possible dose increases to OAR needs to be exercised.