8 results on '"Mai, Wei"'
Search Results
2. Initial experience using intensity-modulated radiotherapy for recurrent nasopharyngeal carcinoma
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Lu, Tai-Xiang, Mai, Wei-Yuan, Teh, Bin S., Zhao, Chong, Han, Fei, Huang, Yin, Deng, Xiao-Wu, Lu, Li-Xia, Huang, Shao-Min, Zeng, Zhi-Fan, Lin, Cheng-Guang, Lu, Hsin H., Chiu, J. Kam, Carpenter, L. Steven, Grant III, Walter H., Woo, Shiao Y., Cui, Nan-Ji, and Butler, E. Brian
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NASOPHARYNX cancer , *RADIOTHERAPY , *SINUSITIS , *LYMPH nodes - Abstract
: PurposeTo report our initial experience on the feasibility, toxicity, and tumor control using intensity-modulated radiotherapy (IMRT) for retreatment of recurrent nasopharyngeal carcinoma (NPC).: Methods and materialsA total of 49 patients with locoregional recurrent carcinoma in the nasopharynx were treated with IMRT between January 2001 and February 2002 at the Sun Yat-Sen University Cancer Center, Guangzhou, China. The average time to the nasopharyngeal recurrence was 30.2 months after initial conventional RT. The median isocenter dose to the nasopharynx was 70 Gy (range 60.9–78.0) for the initial conventional RT. All patients were restaged at the time of recurrence according to the 1992 Fuzhou, China staging system on NPC. The number of patients with Stage I, II, III and IV disease was 4, 9, 10, and 26, respectively. T1, T2, T3, and T4 disease was found in 4, 9, 11, and 25 patients, respectively. N0, N1, N2, and N3 disease was found in 46, 2, 0, and 1 patient, respectively. Invasion of the nasal cavity, maxillary sinus, ethmoid sinus, sphenoid sinus, and cavernous sinus and erosion of the base of the skull was found in 8, 1, 3, 8, 15, and 20 patients, respectively. The gross tumor volume (GTV) was contoured according to the International Commission on Radiation Units and Measurements (ICRU) Report 62 guidelines. The critical structures were contoured, and the doses to critical structures were constrained according to ICRU 50 guidelines. The GTV in the nasopharynx and positive lymph nodes in the neck received a prescription dose of 68–70 Gy and 60 Gy, respectively. All patients received full-course IMRT. Three patients who had positive lymph nodes were treated with five to six courses of chemotherapy (cisplatin + 5-fluorouracil) after IMRT.: ResultsThe treatment plans showed that the percentage of GTV receiving 95% of the prescribed dose (V95-GTV) was 98.5%, and the dose encompassing 95% of GTV (D95-GTV) was 68.1 Gy in the nasopharynx. The mean dose to the GTV was 71.4 Gy. The average doses of the surrounding critical structures were much lower than the tolerable thresholds. At a median follow-up of 9 months (range 3–13), the locoregional control rate was 100%. Three cases (6.1%) of locoregional residual disease were seen at the completion of IMRT, but had achieved a complete response at follow-up. Three patients developed metastases at a distant site: two in the bone and one in the liver and lung at 13 months follow-up. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. Tumor necrosis was seen toward the end of IMRT in 14 patients (28.6%).: ConclusionThe improvement in tumor target coverage and significant sparing of adjacent critical structures allow the feasibility of IMRT as a retreatment option for recurrent NPC after initial conventional RT. This is the first large series using IMRT to reirradiate local recurrent NPC after initial RT failed. The treatment-related toxicity profile was acceptable. The initial tumor response/local control was also very encouraging. In contrast to primary NPC, recurrent NPC reirradiated with high-dose IMRT led to the shedding of tumor necrotic tissue toward the end of RT. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome. [Copyright &y& Elsevier]
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- 2004
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3. Long-term Outcomes and Prognostic Factors of Re-irradiation for Locally Recurrent Nasopharyngeal Carcinoma using Intensity-modulated Radiotherapy
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Han, Fei, Zhao, Chong, Huang, Shao-Min, Lu, Li-Xia, Huang, Ying, Deng, Xiao-Wu, Mai, Wei-Yuan, Teh, Bin S., Butler, E. Brian, and Lu, Tai-Xiang
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MULTIVARIATE analysis , *HEALTH outcome assessment , *RADIATION doses , *RADIOTHERAPY , *SURVIVAL , *TUMOR classification , *DISEASE relapse , *TREATMENT effectiveness , *RETROSPECTIVE studies , *PATIENT selection , *PROGNOSIS ,NASOPHARYNX tumors - Abstract
Abstract: Aims: To analyse the outcomes and to evaluate the prognostic factors involved in the re-irradiation of locally recurrent nasopharyngeal carcinoma (NPC) using intensity-modulated radiotherapy (IMRT). Materials and methods: A retrospective analysis of 239 NPC patients with local recurrence who were re-irradiated with IMRT between 2001 and 2008 was conducted. The distribution of disease re-staging was 5.4% for stage I, 18.4% for stage II, 29.7% for stage III and 46.4% for stage IV. Cisplatin-based chemotherapy was administered to 117 patients (49.0%) in addition to the IMRT. Results: The mean D95 and the V95 of the gross tumour volume (GTV) were 66.78Gy and 98.61%, respectively. The mean dose to the GTV was 70.04Gy (61.73–77.54Gy). The 5 year overall survival, local recurrence-free survival, distant metastasis-free survival and disease-free survival were 44.9, 85.8, 80.6 and 45.4%, respectively. In a univariate analysis, patient age, recurrent T (rT), recurrent N (rN), recurrent stage, tumour volume, mean dose and mean fractional dose of the GTV were significant prognostic factors for overall survival. In a multivariate analysis, only patient age, rN stage, recurrent stage, mean fractional dose and tumour volume remained significant for overall survival. Conclusions: Re-irradiation using IMRT is available to improve local tumour control and to prolong patients’ survival. A smaller tumour volume, higher fractional dose, younger patient ages, lower rN0 stage and early recurrent stage are all independent prognostic factors for overall survival of recurrent NPC. It is of clinical importance to select the appropriate recurrent NPC cases for salvage re-irradiation by IMRT. [Copyright &y& Elsevier]
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- 2012
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4. Sustained long-term immune responses after in situ gene therapy combined with radiotherapy and hormonal therapy in prostate cancer patients
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Fujita, Tetsuo, Teh, Bin S., Timme, Terry L., Mai, Wei-Yuan, Satoh, Takefumi, Kusaka, Nobuyuki, Naruishi, Koji, Fattah, Elmoataz Abdel, Aguilar-Cordova, Estuardo, Butler, E. Brian, and Thompson, Timothy C.
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CANCER treatment , *GENE therapy , *PROSTATE cancer , *CANCER patients , *T cells , *LYMPHOCYTES , *IMMUNE response , *INJECTIONS , *RADIOTHERAPY , *HORMONE therapy - Abstract
Purpose: To explore long-term immune responses after combined radio-gene-hormonal therapy. Methods and Materials: Thirty-three patients with prostate specific antigen 10 or higher or Gleason score of 7 or higher or clinical stage T2b to T3 were treated with gene therapy that consisted of 3 separate intraprostatic injections of AdHSV-tk on Days 0, 56, and 70. Each injection was followed by 2 weeks of valacyclovir. Intensity-modulated radiation therapy was delivered 2 days after the second AdHSV-tk injection for 7 weeks. Hormonal therapy was initiated on Day 0 and continued for 4 months or 2.3 years. Blood samples were taken before, during, and after treatment. Lymphocytes were analyzed by fluorescent antibody cell sorting (FACS). Results: Median follow-up was 26 months (range, 4–48 months). The mean percentages of DR+CD8+ T cells were increased at all timepoints up to 8 months. The mean percentages of DR+CD4+ T cells were increased later and sustained longer until 12 months. Long-term (2.3 years) use of hormonal therapy did not affect the percentage of any lymphocyte population. Conclusions: Sustained long-term (up to 8 to 12 months) systemic T-cell responses were noted after combined radio-gene-hormonal therapy for prostate cancer. Prolonged use of hormonal therapy does not suppress this response. These results suggest the potential for sustained activation of cell-mediated immune responses against cancer. [Copyright &y& Elsevier]
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- 2006
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5. Enhanced systemic T-cell activation after in situ gene therapy with radiotherapy in prostate cancer patients
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Satoh, Takefumi, Teh, Bin S., Timme, Terry L., Mai, Wei-Yuan, Gdor, Yehoshua, Kusaka, Nobuyuki, Fujita, Tetsuo, Pramudji, Christina K., Vlachaki, Maria T., Ayala, Gustavo, Wheeler, Thomas, Amato, Robert, Miles, Brian J., Kadmon, Dov, Butler, E. Brian, and Thompson, Timothy C.
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CANCER treatment , *CANCER genetics , *THERAPEUTICS , *GENE therapy - Abstract
Purpose: In situ cytotoxic gene therapy can potentially trigger a systemic immune response, which could impact occult metastatic disease. We are currently conducting three clinical trials using in situ adenoviral vector mediated herpes simplex virus–thymidine kinase (HSV-tk) gene delivery followed by the HSV-tk prodrug ganciclovir (GCV) or valacyclovir (VCV). This study evaluates the systemic T-cell response after gene therapy in each trial.Methods and materials: The study protocol included three separate clinical trials in the Baylor Prostate Cancer SPORE Program: Trial A gene therapy in prostate cancer patients failing radiotherapy (36 patients), Trial B neoadjuvant gene therapy in pre–radical prostatectomy patients (22 patients), and Trial C gene therapy in combination with radiotherapy for prostate cancer (27 patients). Heparinized blood was collected at the time of vector injection and at selected intervals afterward. A complete blood count was performed, and peripheral blood lymphocytes were analyzed by fluorescent antibody cell sorting after labeling with dual color–labeled antibody pairs.Results: The pretreatment mean percentage of activated CD8+ T cells (DR+CD8+ T cells) was 12.23%, 16.72%, and 14.09% (Trials A, B, and C, respectively). Two weeks posttreatment, this increased to 22.87%, 26.15%, and 39.04% (Trials A, B, and C, respectively), and these increases were statistically significant (p = 0.0188, p = 0.0010, p < 0.0001, respectively). The increase of DR+CD8+ T cells was significantly larger in Trial C than in Trial A (p = 0.0044) or Trial B (p = 0.0288). Total CD8+ T cells significantly increased at 2 weeks posttreatment in Trial B and C (p = 0.0013, p = 0.0004, respectively). Interestingly, only in Trial C were significant increases in activated CD4+ T cells seen at 2 weeks (p = 0.0035).Conclusions: This is the first report of systemic T-cell responses after HSV-tk+GCV/VCV gene therapy under three clinical trial conditions. There was an increase in activated CD8+ T cells in the peripheral blood after vector injection, suggesting the potential for activation of components of cell-mediated immune response in all trial conditions. The addition of radiotherapy to in situ gene therapy seems to further increase the total CD8+ T cells and activated CD4+ T cells. [Copyright &y& Elsevier]
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- 2004
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6. IMRT for prostate cancer: Defining target volume based on correlated pathologic volume of disease
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Teh, Bin S., Bastasch, Michael D., Wheeler, Thomas M., Mai, Wei-Yuan, Frolov, Anna, Uhl, Barry M., Lu, Hsin H., Carpenter, L.Steven, Chiu, J.Kam, McGary, John, Woo, Shiao Y., Grant III, Walter H., Butler, E.Brian, and Grant, Walter H 3rd
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PROSTATE cancer , *RADIOTHERAPY , *COMPUTERS in medicine , *ADENOCARCINOMA , *PROSTATECTOMY , *CANCER invasiveness , *RETROSPECTIVE studies , *TUMOR classification , *COMBINED modality therapy , *COMPUTED tomography , *PROSTATE tumors - Abstract
: PurposeThe intensity-modulated radiation therapy (IMRT) treatment planning system generates tightly constricted isodose lines. It is very important to define the margins that are acceptable in the treatment of prostate cancer to maximize the dose escalation and normal tissue avoidance advantages offered by IMRT. It is necessary to take into account subclinical disease and the potential for extracapsular spread. Organ and patient motion as well as setup errors are variables that must be minimized and defined to avoid underdosing the tumor or overdosing the normal tissues. We have addressed these issues previously. The purpose of the study was twofold: to quantify the radial distance of extracapsular extension in the prostatectomy specimens, and to quantify differences between the pathologic prostate volume (PPV), CT-based gross tumor volume (GTV), and planning target volume (PTV).: Methods and materialsTwo related studies were undertaken. A total of 712 patients underwent prostatectomy between August 1983 and September 1995. Pathologic assessment of the radial distance of extracapsular extension was performed. Shrinkage associated with fixation was accounted for with a linear shrinkage factor. Ten patients had preoperative staging studies including a CT scan of the pelvis. The GTV was outlined and volume determined from these CT scans. The PTV, defined as GTV with a 5-mm margin in all dimensions, was then calculated. The Peacock inverse planning system (NOMOS Corp., Sewickley, PA) was used. The PPV, GTV, and PTV were compared for differences and evaluated for correlation.: ResultsExtracapsular extension (ECE) (i.e., prostatic capsular invasion level 3 [both focal and established]) was found in 299 of 712 patients (42.0%). Measurable disease extending radially outside the prostatic capsule (i.e., ECE level 3 established) was noted in 185 of 712 (26.0%). The median radial extension was 2.0 mm (range 0.50–12.00 mm) outside the prostatic capsule. As a group, 20 of 712 (2.8%) had extracapsular extension of more than 5 mm. In the volumetric comparison and correlation study of the GTV and PTV to the PPV, the average GTV was 2 times larger than the PPV. The average PTV was 4.1 times larger than the PPV.: ConclusionsThis is the largest series in the literature quantitatively assessing prostatic capsular invasion (i.e., the radial extracapsular extension). It is the first report of a comparison of PPV to CT-planned GTV and PTV. Using patient and prostate immobilization, 5 mm of margin to the GTV in this study provided sufficient coverage of the tumor volume based on data gathered from 712 patients. In the absence of prostate immobilization, additional margins of differing amounts depending on the technique employed would have to be placed to account for target, patient, and setup uncertainties. The large mean difference between CT-based estimates of the tumor volume and target volume (GTV+PTV) and PPV added further evidence for adequacy of tumor coverage. Target immobilization, setup error, and coverage of subclinical disease must be addressed carefully before successful implementation of IMRT to maximize its ability to escalate dose and to spare normal tissue simultaneously and safely. [Copyright &y& Elsevier]
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- 2003
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7. Dosimetric predictors of xerostomia for head-and-neck cancer patients treated with the smart (simultaneous modulated accelerated radiation therapy) boost technique
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Amosson, Chad M., Teh, Bin S., Van, T.John, Uy, Nathan, Huang, Eugene, Mai, Wei-Yuan, Frolov, Anna, Woo, Shiao Y., Chiu, J.Kam, Carpenter, L.Steven, Lu, Hsin H., Grant III, Walter H., Butler, E.Brian, and Grant, Walter H 3rd
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HEAD & neck cancer , *RADIOTHERAPY - Abstract
: PurposeTo evaluate the predictors of xerostomia in the treatment of head-and-neck cancers treated with intensity-modulated radiation therapy (IMRT), using the simultaneous modulated accelerated radiation therapy (SMART) boost technique. Dosimetric parameters of the parotid glands are correlated to subjective salivary gland function.: Methods and materialsBetween January 1996 and June 2000, 30 patients with at least 6 months follow-up were evaluated for subjective xerostomia after being treated definitively for head-and-neck cancer with the SMART boost technique. Threshold limits for the ipsilateral and contralateral parotid glands were 35 Gy and 25 Gy, respectively. Dosimetric parameters to the parotid glands were evaluated. The median follow-up time was 38.5 months (mean 39.9 months). The results of the dosimetric parameters and questionnaire were statistically correlated.: ResultsXerostomia was assessed with a 10-question subjective salivary gland function questionnaire. The salivary gland function questionnaire (questions 1, 2, 3, 4, 6, and 9) correlated significantly with the dosimetric parameters (mean and maximum doses and volume and percent above tolerance) of the parotid glands. These questions related to overall comfort, eating, and abnormal taste. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands.: ConclusionsQuestions regarding overall comfort, eating, and abnormal taste correlated significantly with the dosimetric parameters of the parotid glands. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands. Dosimetric sparing of the parotid glands improved subjective xerostomia. IMRT in the treatment of head-and-neck cancer can be exploited to preserve the parotid glands and decrease xerostomia. This is feasible even with an accelerated treatment regimen like the SMART boost. More patients need to be evaluated using IMRT to identify relevant dosimetric parameters. [Copyright &y& Elsevier]
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- 2003
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8. ATL>Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity.
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Huang, Eugene, Teh, Bin S., Strother, Douglas R., Davis, Quillin G., Chiu, J. Kam, Lu, Hsin H., Carpenter, L. Steven, Mai, Wei-Yuan, Chintagumpala, Murali M., South, Michael, Grant III, Walter H., Butler, E. Brian, and Woo, Shiao Y.
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DEAFNESS , *MEDULLOBLASTOMA , *CISPLATIN - Abstract
Purpose : The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child’s cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the cochlea and eighth cranial nerve (auditory apparatus).Patients and Methods : Twenty-six pediatric patients treated for medulloblastoma were retrospectively divided into two groups that received either conventional radiotherapy (Conventional-RT Group) or IMRT (IMRT Group). One hundred thirteen pure-tone audiograms were evaluated retrospectively, and hearing function was graded on a scale of 0 to 4 according to the Pediatric Oncology Group’s toxicity criteria. Statistical analysis comparing the rates of ototoxicity was performed using Fisher’s exact test with two-tailed analysis.Results : When compared to conventional radiotherapy, IMRT delivered 68% of the radiation dose to the auditory apparatus (mean dose: 36.7 vs. 54.2 Gy). Audiometric evaluation showed that mean decibel hearing thresholds of the IMRT Group were lower at every frequency compared to those of the Conventional-RT Group, despite having higher cumulative doses of cisplatin. The overall incidence of ototoxicity was lower in the IMRT Group. Thirteen percent of the IMRT Group had Grade 3 or 4 hearing loss, compared to 64% of the Conventional-RT Group (p < 0.014).Conclusion : The conformal technique of IMRT delivered much lower doses of radiation to the auditory apparatus, while still delivering full doses to the desired target volume. Our findings suggest that, despite higher doses of cisplatin, and despite radiotherapy before cisplatin therapy, treatment with IMRT can achieve a lower rate of hearing loss. [Copyright &y& Elsevier]- Published
- 2002
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