145 research outputs found
Commentary: Induction Chemotherapy for Head and Neck Cancer: Hypothesis‐Based Rather Than Evidence‐Based Medicine
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139966/1/onco0975.pd
A Bayesian Mixture Model Relating Dose to Critical Organs and Functional Complication in 3D Conformal Radiation Therapy
A goal of radiation therapy is to deliver maximum dose to the target tumor while minimizing complications due to irradiation of critical organs. Technological advances in 3D conformal radiation therapy has allowed great strides in realizing this goal, however complications may still arise. Critical organs may be adjacent to tumors or in the path of the radiation beam. Several mathematical models have been proposed that describe a relationship between dose and observed functional complication, however only a few published studies have successfully fit these models to data using modern statistical methods which make efficient use of the data. One complication following radiation therapy of head and neck cancers is the patient’s inability to produce saliva. Xerostomia (dry mouth) leads to high susceptibility to oral infection and dental caries and is, in general, unpleasant and an annoyance. We present a dose-damage-injury model that can accommodate any of the various mathematical models relating dose to damage. The model is a non-linear, longitudinal mixed effects model where the outcome (saliva flow rate) is modeled as a mixture of a Dirac measure at zero and a gamma distribution whose mean is a function of time and dose. Bayesian methods are used to estimate the relationship between dose delivered to the parotid glands and the observational outcome – saliva flow rate. A summary measure of the dose-damage relationship is modeled and assessed by a Bayesian x2 test for goodness-of-fit
The role of technetium-99m methoxyisobutyl isonitrile scintigraphy in predicting the therapeutic effect of chemotherapy against nasopharyngeal carcinoma
BACKGROUND: The authors prospectively evaluated the correlation between technetium-99m methoxyisobutyl isonitrile ( 99m Tc-MIBI) accumulation in tumors and response to induction chemotherapy in patients with nasopharyngeal carcinoma (NPC). METHODS: Eighty-six patients with locally advanced NPC underwent single-photon emission computed tomography 15 minutes after an intravenous injection of 740 megabecquerels (20 mCi) 99m Tc-MIBI before chemotherapy. The tumor uptake ratio (TUR) was calculated. Two weeks after the second cycle of combined chemotherapy with 5-fluorouracil (5-FU) and cisplatin (DDP), the tumor response rate was evaluated. The correlation between 99m Tc-MIBI accumulation in tumors and response to chemotherapy with 5-FU/DDP was examined. RESULTS: Positive accumulation of 99m Tc-MIBI in tumors was observed in 76 patients (88.4%). The tumor response was a complete response (CR) in 8 patients, a partial response (PR) in 68 patients, stable disease (SD) in 9 patients, and progressive disease (PD) in 1 patient. The response rate (CR and PR) to 5-FU/DDP chemotherapy in patients who had positive 99m Tc-MIBI accumulation (tumor uptake ratio [TUR] >1.1) was higher than that in patients who had negative 99m Tc-MIBI accumulation (TUR ≤1.1; 98.7% vs 10%; P < .001). CONCLUSIONS: Patients with negative 99m Tc-MIBI accumulation were resistant to 5-FU/DDP chemotherapy. 99m Tc-MIBI imaging in patients with NPC was capable of predicting tumor response to chemotherapy with 5-FU/DDP and can help in the selection of patients for induction chemotherapy. Cancer 2011. © 2010 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84384/1/25802_ftp.pd
Neck spasm after chemoradiotherapy for head and neck cancer: Natural history and dosimetric correlates
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102727/1/hed23284.pd
Radiotherapy Dose–Volume Effects on Salivary Gland Function
Publications relating parotid dose-volume characteristics to radiotherapy-induced salivary toxicity were reviewed. Late salivary dysfunction has been correlated to the mean parotid gland dose, with recovery occurring with time. Severe xerostomia (defined as long-term salivary function of <25% of baseline) is usually avoided if at least one parotid gland is spared to a mean dose of less than ≈20 Gy or if both glands are spared to less than ≈25 Gy (mean dose). For complex, partial-volume RT patterns (e.g., intensity-modulated radiotherapy), each parotid mean dose should be kept as low as possible, consistent with the desired clinical target volume coverage. A lower parotid mean dose usually results in better function. Submandibular gland sparing also significantly decreases the risk of xerostomia. The currently available predictive models are imprecise, and additional study is required to identify more accurate models of xerostomia risk
Safety considerations for IMRT: Executive summary
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98742/1/MPH005067.pd
Volumetric 18F‐FDG‐PET parameters as predictors of locoregional failure in low‐risk HPV‐related oropharyngeal cancer after definitive chemoradiation therapy
BackgroundWe sought to investigate the prognostic value of volumetric positron emission tomography (PET) parameters in patients with human papillomavirus (HPV)‐related oropharyngeal squamous cell carcinoma (OPSCC) and a ≤10 pack‐year smoking history treated with chemoradiation.MethodsA total of 142 patients were included. Maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor, involved regional lymph nodes, and total lesion were calculated. Cox proportional hazard modeling was used to evaluate associations of clinical and PET parameters with locoregional failure‐free survival (LRFFS), distant metastasis‐free survival (DMFS), and overall survival (OS).ResultsOn univariate analysis, volumetric PET parameters were significantly associated with all endpoints, and 8th edition American Joint Committee on Cancer/Union Internationale Contre le Cancer staging was significantly associated with DMFS and OS. On multivariate analysis, total lesion TLG was significantly associated with LRFFS, while staging was most significantly prognostic for DMFS and OS.ConclusionVolumetric PET parameters are uniquely prognostic of LRFFS in low‐risk HPV‐related OPSCC and may be useful for directing de‐intensification strategies.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147800/1/hed25505_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147800/2/hed25505.pd
Classification of TP53 mutations and HPV predict survival in advanced larynx cancer
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/1/lary25915-sup-0001-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/2/lary25915_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/3/lary25915.pd
Radiation-Induced Sarcomas of the Head and Neck : A Systematic Review
Introduction As a result of the increased use of radiotherapy (RT) and improved long-term overall survival of patients with cancers of the head and neck (HN), the frequency of radiation-induced sarcomas of the head and neck (RISHN) may be increasing. The main objective of this systematic review was to determine the existing evidence on the frequency, treatment, and outcome of RISHN. Methods Using PRISMA guidelines we conducted a systematic review of the literature published from 2000 to 2020. Results Our review includes data of 560 patients from 64 articles. The total frequency of RISHNs among the reviewed series was 0.15%. The most frequent location of the primary tumor treated by RT was the nasopharynx. The mean RT dose used was 62 Gy, mean latency interval between irradiation and occurrence of RISHN was 11.1 years, and the most common RISHN location was the sinonasal region. Osteosarcoma was the principal histology, followed by fibrosarcoma. Surgery was the most frequently applied treatment modality. Of all patients with RISHN, 40.7% died of this disease after a mean interval of 13.9 months. Conclusions Notwithstanding the increased use of RT, the number of reported RISHNs has not increased substantially during the past two decades. Surgery with wide margins forms the best therapeutic option for these cases, but the outcome remains poor.Peer reviewe
- …