International journal of radiation oncology, biology, physics
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Increased therapeutic ratio by 18FDG-PET CT planning in patients with clinical CT stage N2-N3M0 non-small-cell lung cancer: a modeling study.
With this modeling study, we wanted to estimate the potential gain from incorporating fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning in the radiotherapy treatment planning of CT Stage N2-N3M0 non-small-cell lung cancer (NSCLC) patients. ⋯ In this group of clinical CT Stage N2-N3 NSCLC patients, use of FDG-PET scanning information in radiotherapy planning reduced the radiation exposure of the esophagus and lung, and thus allowed significant radiation dose escalation while respecting all relevant normal tissue constraints. This, together with a reduced risk of geographic misses using PET-CT, led to an estimated increase in TCP from 13% to 18%. The results of this modeling study support clinical trials investigating incorporation of FDG-PET information in CT-based radiotherapy planning.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Adequate margins for random setup uncertainties in head-and-neck IMRT.
To investigate the effect of random setup uncertainties on the highly conformal dose distributions produced by intensity-modulated radiotherapy (IMRT) for clinical head-and-neck cancer patients and to determine adequate margins to account for those uncertainties. ⋯ The margins to account for random setup uncertainties, in our clinical IMRT solution, should be 1.5 mm and 3.0 mm in the case of sigma = 2 mm and sigma = 4 mm, respectively, for the CTV(primary). Larger margins (5.0 mm), however, should be applied to the CTV(elective), if the goal of treatment is a V(95) value of at least 99%.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
The pattern of lymphatic metastasis of breast cancer and its influence on the delineation of radiation fields.
The delineation of radiation fields should cover the clinical target volume (CTV) and minimally irradiate the surrounding normal tissues and organs. This study was designed to explore the pattern of lymphatic metastasis of breast cancer and indications for radiotherapy after radical or modified radical mastectomy and to discuss the rational delineation of radiation fields. ⋯ According to our data, we suggest that the radiation field for internal mammary lymph nodes should exclude the fourth and fifth intercostal spaces, which may help to reduce the radiation damage to heart. It is unnecessary to irradiate the supraclavicular lymph nodes for the patients with negative axillary level III nodes, even with positive level I and level II nodes.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Improved biochemical outcome with adjuvant radiotherapy after radical prostatectomy for prostate cancer with poor pathologic features.
The indications for adjuvant external beam radiotherapy (EBRT) after radical prostatectomy (RP) are poorly defined. We performed a retrospective comparison of our institution's experience treating prostate cancer with RP vs. RP followed by adjuvant EBRT. ⋯ Adjuvant RT demonstrated improved efficacy against prostate cancer. For patients with poor pathologic features (extracapsular extension, seminal vesicle invasion, positive margins), adjuvant RT improved the biochemical outcome independent of other prognostic factors.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Randomized Controlled Trial Multicenter Study Clinical TrialAccelerated versus conventional fractionated postoperative radiotherapy for advanced head and neck cancer: results of a multicenter Phase III study.
To determine whether, in the postoperative setting, accelerated fractionation (AF) radiotherapy (RT) yields a superior locoregional control rate compared with conventional fractionation (CF) RT in locally advanced squamous cell carcinomas of the oral cavity, oropharynx, larynx, or hypopharynx. ⋯ Accelerated fractionation does not seem to be worthwhile for squamous cell carcinoma of the head and neck after resection; however, AF might be an option for patients who delay starting RT.