37 research outputs found

    Definitive radiotherapy for early stage glottic cancer by 6 MV photons

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    Purpose: To evaluate the clinical outcome of early glottic cancer (GC) treated by primary radiotherapy (RT) with 6 MV photons. Methods and materials: We retrospectively reviewed the medical records of 695 consecutive patients with T1N0 and T2N0 GC treated between 1983 and 2005 by RT in our institution. Clinical outcome in terms of local control (LC), overall survival (OS) and cause- specific survival (CSS) rate were evaluated. Results: The median follow-up time was 10.5 years.The 10-year actuarial LC rates were as follows: T1A, 91%; T1B, 87%; T2, 77%. The 10-year OS were as follows: T1, 74.2%; T2, 70.7%. The 10-year CSS were as follows: T1, 97.7%; T2, 97.1%. Poorly differentiated histology and tumor biologically effective dose < 65 Gy.© 2012 Tong et al.; licensee BioMed Central Ltd.Link_to_subscribed_fulltex

    Impact and relationship of anterior commissure and time-dose factor on the local control of T1N0 glottic cancer treated by 6 MV photons

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    <p>Abstract</p> <p>Background</p> <p>To evaluate prognostic factors that may influence local control (LC) of T1N0 glottic cancer treated by primary radiotherapy (RT) with 6 MV photons.</p> <p>Methods</p> <p>We retrospectively reviewed the medical records of 433 consecutive patients with T1N0 glottic cancer treated between 1983 and 2005 by RT in our institution. All patients were treated with 6 MV photons. One hundred and seventy seven (41%) patients received 52.5 Gy in 23 fractions with 2.5 Gy/fraction, and 256 (59%) patients received 66 Gy in 33 fractions with 2 Gy/fraction.</p> <p>Results</p> <p>The median follow-up time was 10.5 years. The 10-year LC rates were 91% and 87% for T1a and T1b respectively. Multivariate analysis showed LC rate was adversely affected by poorly differentiated histology (Hazard Ratio [HR]: 7.5, <it>p </it>= 0.035); involvement of anterior commissure (HR: 2.34, <it>p </it>= 0.011); fraction size of 2.0 Gy (HR: 2.17, <it>p </it>= 0.035) and tumor biologically effective dose (BED) < 65 Gy<sub>15 </sub>(HR: 3.38, <it>p </it>= 0.017).</p> <p>Conclusions</p> <p>The negative impact of anterior commissure involvement could be overcome by delivering a higher tumor BED through using fraction size of > 2.0 Gy. We recommend that fraction size > 2.0 Gy should be utilized, for radiation schedules with five daily fractions each week.</p

    Differentiated thyroid cancer in Hong Kong

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    published_or_final_versionMedicineMasterDoctor of Medicin

    Cervical nodal metastases from occult primary: Undifferentiated carcinoma versus squamous cell carcinoma

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    Purpose/ObjecControversy exists regarding the management of cervical lymph node metastases from occult primary. Oncologists face a major challenge in adopting an optimal approach. This study attempted to compare the clinical course of two different histologic findings of this disease entity. Materials and Methods. A retrospective analysis was performed for all patients referred to our institution between 1988 and 1998 with cervical lymph node metastases from an unknown primary. Case records of consecutive unselected patients with histologically confirmed carcinoma in cervical lymph nodes were reviewed. Those with histologic findings other than squamous cell carcinoma (SCC) or undifferentiated carcinoma (UDC) and lymphadenopathies at the supraclavicular fossa alone or below the clavicles at the time of diagnosis were excluded. There were 45 patients identified with a mean follow-up of 36 months (range, 4-110 months). Thirty-seven were men and eight were women. The mean age was 57 (range, 29-91). There were 32 patients with SCC and 13 patients with UDC. Treatment modality included surgery (S) alone in 1 patient (2%), radiotherapy (RT) alone in 24 patients (53%), and combined modality in 20 patients (45%). (Twelve patients (27%) had combined S and RT, 8 patients (18%) had combined chemotherapy and RT.) Twenty-eight patients (62%) were treated with radical intent. For those patients treated by radical RT, the RT field covered both sides of the neck and the potential mucosal primary (PMP) sites, including the entire pharyngeal axis. The median radiation doses to the lymph nodes and the PMP were 65 Gy (range, 60-70 Gy) and 60 Gy (range, 40-70 Gy), respectively. Results. At the time of analysis, ultimate control of disease above the clavicles according to N stage, treatment intent, and histologic type was as follows: N1s, 7 of 7 (100%); N2s, 15 of 26 (58%); N3s, 1 of 12 (8%); radical intent, 19 of 28 (68%); palliative intent, 3 of 17 (18%); UDC, 11 of 13 (85%); SCC, 11 of 32 (34%). Eleven patients remained alive and disease free, with a median follow-up of 79 months (range, 27-110 months). The 5-year disease-specific survival (DSS) for the radical treatment group and the palliative treatment group were 67% and 18%, respectively (p = .0011). Significant difference in 5-year DSS was observed among the different N groups: 100% for N1s, 55% for N2s, and 0% for N3s, respectively (p = .0001). There was also a significant difference in the 5-year DSS between UDC and SCC: 81% for UDC vs 34% for SCC (p = .01). No significant difference in the 5-year DSS was observed on the basis of treatment modality in the radically treated group: 63% for RT alone vs 75% for S + RT (p = .711). Conclusions. UDC histologic findings in our series are associated with better locoregional control and DSS than SCC. Our results in local control, emergence of primary tumor, and DSS are comparable with other published data. However, disease control of advanced nodal stage remains poor; more aggressive treatment approaches, like the use of concurrent chemoradiation or altered fractionation scheme, should be explored. © 2002 Wiley Periodicals, Inc.Link_to_subscribed_fulltex

    Single microcrystals of organoplatinum(II) complexes with high charge-carrier mobility

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    Hydrogen-bonding pyrazolyl and imidazolyl motifs are incorporated into organoplatinum(II) complexes and found to be harmonized with extended π–π and PtII⋯PtII interactions to align the planar cations into a quasi-1-D columnar structure or a quasi-2D framework. A field-effect electron mobility up to 20 cm2V−1s−1 has been recorded with a single-microcrystal transistor. In addition, crystalline samples of one of the organoplatinum(II) complexes show intriguing thermoluminescent and vapoluminescent properties
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