Search results for "Dose Fractionation"
showing 10 items of 29 documents
Phase III Study of Surgery Versus Definitive Concurrent Chemoradiotherapy Boost in Patients With Resectable Stage IIIA(N2) and Selected IIIB Non-Smal…
2015
Purpose Concurrent chemoradiotherapy with or without surgery are options for stage IIIA(N2) non–small-cell lung cancer. Our previous phase II study had shown the efficacy of induction chemotherapy followed by chemoradiotherapy and surgery in patients with IIIA(N2) disease and with selected IIIB disease. Here, we compared surgery with definitive chemoradiotherapy in resectable stage III disease after induction. Patients and Methods Patients with pathologically proven IIIA(N2) and selected patients with IIIB disease that had medical/functional operability received induction chemotherapy, which consisted of three cycles of cisplatin 50 mg/m2 on days 1 and 8 and paclitaxel 175 mg/m2 on day 1 ev…
Rectal cancer: mucinous carcinoma on magnetic resonance imaging indicates poor response to neoadjuvant chemoradiation.
2010
Purpose To assess response of locally advanced rectal carcinoma to chemoradiation with regard to mucinous status and local tumor invasion found at pretherapeutic magnetic resonance imaging (MRI). Methods and Materials A total of 88 patients were included in this prospective study of patients with advanced mrT3 and mrT4 carcinomas. Carcinomas were categorized by MRI as mucinous (mucin proportion >50% within the tumor volume), and as nonmucinous. Patients received neoadjuvant chemoradiation consisting of 50.4 Gy (1.8 Gy/fraction) and 5-fluorouracil on Days 1 to 5 and Days 29 to 33. Therapy response was assessed by comparing pretherapeutic MRI with histopathology of surgical specimens (minimum…
Stereotactic fractionated radiotherapy in patients with optic nerve sheath meningioma.
2002
Abstract Purpose: To evaluate the effectiveness of stereotactic fractionated radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1994 and 2000, a total of 39 patients with either primary ( n = 15) or secondary ( n = 24) ONSM were treated with SFRT and received a median total tumor dose of 54 Gy using 1.8 Gy/fraction. Results: The radiographic response to SFRT was documented in all patients as stable disease (no change) except for 1 patient with a partial response. After a median follow-up of 35.5 months, all patients with ONSM were alive without recurrence. The visual fields and visual acuity were improved in 6 of 15 and 1 of 16 exami…
Biodosimetry Based on γ-H2AX Quantification and Cytogenetics after Partial- and Total-Body Irradiation during Fractionated Radiotherapy
2015
The aim of this current study was to quantitatively describe radiation-induced DNA damage and its distribution in leukocytes of cancer patients after fractionated partial- or total-body radiotherapy. Specifically, the impact of exposed anatomic region and administered dose was investigated in breast and prostate cancer patients receiving partial-body radiotherapy. DNA double-strand breaks (DSBs) were quantified by γ-H2AX immunostaining. The frequency of unstable chromosomal aberrations in stimulated lymphocytes was also determined and compared with the frequency of DNA DSBs in the same samples. The frequency of radiation-induced DNA damage was converted into dose, using ex vivo generated ca…
Hypo-fractionated stereotactic radiation therapy for lung malignancies by means of helical tomotherapy: report of feasibility by a single-center expe…
2018
Background: Several experiences in the literature report SBRT as an effective treatment option for medically inoperable early stage non-small cell lung cancer (NSCLC) and oligometastatic disease. The optimal fractionation schedules and total dose remain controversial. In this study, we evaluated the safety in terms of toxicity and efficacy of using of 8â10 fractions schedules with Helical Tomotherapy (HT) for primary and metastatic lung lesions. Methods: Between March 2014 and May 2016, a total of 39 patients (median age 72 years, range 26â91) were treated with HT-SBRT for malignant lung lesions: 22 patients with early stage NSCLC, 17 with oligometastases. Patients received 8â10 fract…
Stereotactic fractionated irradiation of optic nerve sheath meningioma: a new treatment alternative
2002
Background: Primary optic nerve sheath meningioma (ONSM) is a rare but almost invariably blinding tumour when its natural history is observed in a “wait and see” strategy. Surgery has hitherto only been advocated in case of progressive disease involving intracranial structures, as it leads to iatrogenic blindness in the overwhelming majority of cases. Therefore, treatment options bearing lesser risk of functional deterioration are highly desirable, both in cases of intracranial involvement as well as during earlier phases of the disease which are currently generally left untreated. The authors report the outcome of the largest series of patients to date treated by stereotactic fractionated …
Erythropoietin restores the anemia-induced reduction in radiosensitivity of experimental human tumors in nude mice
2003
Abstract Purpose The effect of recombinant human erythropoietin (rhEPO) on the radiosensitivity of human tumor xenografts growing in anemic and nonanemic nude mice was studied. Methods and materials Anemia was induced by total body irradiation ([TBI], 2 × 4 Gy) of mice before tumor implantation into the subcutis of the hind leg. The development of anemia was prevented by rhEPO (750 U/kg s.c.) given 3 times weekly starting 2 weeks before TBI. Fourteen days after fractionated TBI (tumor volume of approx. 40 mm 3 ), single-dose irradiation of the tumor with varying doses was performed so that in full dose–response relationship for the probability of tumor cure was obtained. Results Radiation-i…
Fractionated External Beam Radiotherapy as a Suitable Preparative Regimen for Hepatocyte Transplantation After Partial Hepatectomy
2010
Purpose Hepatocyte transplantation is strongly considered to be a promising option to correct chronic liver failure through repopulation of the diseased organ. We already reported on extensive liver repopulation by hepatocytes transplanted into rats preconditioned with 25-Gy single dose selective external beam irradiation (IR). Herein, we tested lower radiation doses and fractionated protocols, which would be applicable in clinical use. Methods and Material Livers of dipeptidylpeptidase IV (DPPIV)-deficient rats were preconditioned with partial liver external beam single dose IR at 25 Gy, 8 Gy, or 5 Gy, or fractionated IR at 5 × 5 Gy or 5 × 2 Gy. Four days after completion of IR, a partial …
Primary optic nerve sheath meningioma
2007
BACKGROUND. Radiotherapy (RT) has occasionally been practiced in the treatment of optic nerve sheath meningioma (ONSM). Recently, stereotactic fractionated RT (SFRT) has been introduced as a tool with better precision for RT delivery. A comprehensive review was undertaken to provide more insight into this matter. METHODS. A literature search was performed to identify reports dealing with both clinical aspects (diagnosis) and treatment in ONSM, focusing on RT in primary (p)ONSM. In particular, major emphasis was placed on the role of SFRT in pONSM. RESULTS. SFRT was capable of achieving excellent local tumor control, with improved/stable functional capacity in ≥80%, accompanied with very low…
Intensity-modulated extended-field chemoradiation plus simultaneous integrated boost in the pre-operative treatment of locally advanced cervical canc…
2015
Objective: To investigate the feasibility and determine the recommended pre-operative intensity-modulated radiotherapy (IMRT) dose of extended-field chemoradiation along with simultaneous integrated boost (SIB) dose escalation. Methods: A radiation dose of 40Gy over 4 weeks, 2Gy/fraction, was delivered to the tumour and the lymphatic drainage (planning target volume, PTV3), which encompassed a volume larger than standard (common iliac lymphatic area up to its apex, in front of the L3 vertebra), concurrently with chemotherapy (cisplatin and 5-fluorouracil). Radiation dose was escalated to the pelvis (PTV2) and to the macroscopic disease (PTV1) with the SIB-IMRT strategy. Three dose levels we…