• Title, Summary, Keyword: helical tomotherapy

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Comparison of survival rates between patients treated with conventional radiotherapy and helical tomotherapy for head and neck cancer

  • Kong, Moonkyoo;Hong, Seong Eon;Choi, Jinhyun;Kim, Youngkyong
    • Radiation Oncology Journal
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    • v.31 no.1
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    • pp.1-11
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    • 2013
  • Purpose: Compared to conventional radiotherapy (RT), intensity-modulated radiotherapy (IMRT) significantly reduces the rate of treatment-induced late toxicities in head and neck cancer. However, a clear survival benefit of IMRT over conventional RT has not yet been shown. This study is among the first comparative study to compare the survival rates between conventional RT and helical tomotherapy in head and neck cancer. Materials and Methods: From January 2008 to November 2011, 37 patients received conventional RT and 30 patients received helical tomotherapy for management of head and neck cancer. We retrospectively compared the survival rates between patients treated with conventional RT and helical tomotherapy, and analyzed the prognostic factors for survival. Results: The 1- and 2-year locoregional recurrence-free survival rates were 61.2% and 58.1% for the conventional RT group, 89.3% and 80.3% for the helical tomotherapy group, respectively. The locoregional recurrence-free survival rates of the helical tomotherapy group were significantly higher than conventional RT group (p = 0.029). There were no significant differences in the overall and distant metastasis-free survival between the two groups. RT technique, tumor stage, and RT duration were significant prognostic factors for locoregional recurrence-free survival. Conclusion: This study showed the locoregional recurrence-free survival benefits of helical tomotherapy in the treatment of head and neck cancers.

Clinical Outcome of Helical Tomotherapy for Inoperable Non-Small Cell Lung Cancer: The Kyung Hee University Medical Center Experience

  • Kong, Moonkyoo;Hong, Seong Eon
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1545-1549
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    • 2014
  • Background: Published studies on clinical outcome of helical tomotherapy for lung cancer are limited. The purpose of this study was to evaluate clinical outcomes and treatment-related toxicity in inoperable non-small cell lung cancer (NSCLC) patients treated with helical tomotherapy in Korea. Materials and Methods: Twenty-seven patients with NSCLC were included in this retrospective study. Radiotherapy was performed using helical tomotherapy with a daily dose of 2.1-3 Gy delivered at 5 fractions per week resulting in a total dose of 62.5-69.3 Gy. We assessed radiation-related lung and esophageal toxicity, and analyzed overall survival, locoregional recurrence-free survival, distant metastasis-free survival, and prognostic factors for overall survival. Results: The median follow-up period was 28.9 months (range, 10.1-69.4). The median overall survival time was 28.9 months, and 1-, 2-, and 3-year overall survival rates were 96.2%, 92.0%, and 60.0%. The median locoregional recurrence-free survival time was 24.3 months, and 1-, 2-, and 3-year locoregional recurrence-free survival rates were 85.2%, 64.5%, and 50.3%. The median distant metastasis-free survival time was 26.7 months, and 1-, 2-, and 3-year distant metastasis-free survival rates were 92.3%, 83.9%, and 65.3%, respectively. Gross tumor volume was the most significant prognostic factor for overall survival. No grade 4 or more toxicity was observed. Conclusions: Helical tomotherapy in patients with inoperable NSCLC resulted in high survival rates with an acceptable level of toxicity, suggesting it is an effective treatment option in patients with medically inoperable NSCLC.

Magnetic resonance image-based tomotherapy planning for prostate cancer

  • Jung, Sang Hoon;Kim, Jinsung;Chung, Yoonsun;Keserci, Bilgin;Pyo, Hongryull;Park, Hee Chul;Park, Won
    • Radiation Oncology Journal
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    • v.38 no.1
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    • pp.52-59
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    • 2020
  • Purpose: To evaluate and compare the feasibilities of magnetic resonance (MR) image-based planning using synthetic computed tomography (sCT) versus CT (pCT)-based planning in helical tomotherapy for prostate cancer. Materials and Methods: A retrospective evaluation was performed in 16 patients with prostate cancer who had been treated with helical tomotherapy. MR images were acquired using a dedicated therapy sequence; sCT images were generated using magnetic resonance for calculating attenuation (MRCAT). The three-dimensional dose distribution according to sCT was recalculated using a previously optimized plan and was compared with the doses calculated using pCT. Results: The mean planning target volume doses calculated by sCT and pCT differed by 0.65% ± 1.11% (p = 0.03). Three-dimensional gamma analysis at a 2%/2 mm dose difference/distance to agreement yielded a pass rate of 0.976 (range, 0.658 to 0.986). Conclusion: The dose distribution results obtained using tomotherapy from MR-only simulations were in good agreement with the dose distribution results from simulation CT, with mean dose differences of less than 1% for target volume and normal organs in patients with prostate cancer.

Comparison of Linear Accelerator and Helical Tomotherapy Plans for Glioblastoma Multiforme Patients

  • Koca, Timur;Basaran, Hamit;Sezen, Duygu;Karaca, Sibel;Ors, Yasemin;Arslan, Deniz;Aydin, Aysen
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7811-7816
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    • 2014
  • Background: Despite advances in radiotherapy, overall survival of glioblastoma multiforme (GBM) patients is still poor. Moreover dosimetrical analyses with these newer treatment methods are insufficient. The current study is aimed to compare intensity modulated radiation therapy (IMRT) linear accelerator (linac) and helical tomotherapy (HT) treatment plans for patients with prognostic aggressive brain tumors. Material and Methods: A total of 20 GBM patient plans were prospectively evaluated in both linac and HT planning systems. Plans are compared with respect to homogenity index, conformity index and organs at risk (OAR) sparing effects of the treatments. Results: Both treatment plans provided good results that can be applied to GBM patients but it was concluded that if the critical organs with relatively lower dose constraints are closer to the target region, HT for radiotherapeutical application could be preferred. Conclusion: Tomotherapy plans were superior to linear accelerator plans from the aspect of OAR sparing with slightly broader low dose ranges over the healthy tissues. In case a clinic has both of these IMRT systems, employment of HT is recommended based on the observed results and future re-irradiation strategies must be considered.

Evaluation of Ovary Dose for woman of Childbearing age Woman with Breast cancer in tomotherapy (가임기 여성의 유방암 토모치료 시 난소선량 평가비교)

  • Lee, Soo Hyeung;Park, Soo Yeun;Choi, Ji Min;Park, Ju Young;Kim, Jong Suk
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.337-343
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    • 2014
  • Purpose : The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. Materials and Methods : The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Results : Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of $64.94{\pm}0.84mGy$ and $37.64{\pm}1.20mGy$ in left ovary part and average of $64.38{\pm}1.85mGy$ and $32.96{\pm}1.11mGy$ in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Conclusion : Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

Extra Dose Measurement of Differential Slice Thickness of MVCT Image with Helical Tomotherapy (토모테라피 치료 시 MVCT Image의 Slice Thickness 차이에 따른 선량 비교)

  • Lee, Byungkoo;Kang, Suman
    • Journal of the Korean Society of Radiology
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    • v.7 no.2
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    • pp.145-149
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    • 2013
  • Helical Tomotherapy is an innovative means of delivering intensity modulated radiation therapy (IMRT) using a device that merges features of a linear accelerator and helical computed tomography (CT) scanner. Hereat, during helical tomotherapy process, megavoltage computed tomography (MVCT) image are usually used for guiding the precise set-up of patient before/after treatment delivery. But which would certainly increase the total dose for patients, this study was to investigate the imaging dose of MVCT using the cylindrical "Cheese" phantom on a tomotherapy machine. A set of cylindrical "Cheese" phantom was adopted for scanning with respectively pitch value (1, 2, 3 mm) with same number slice (10 slice), same length (approximately 9 cm) and phantom set-ups on the couch of tomotherapy system. The average MVCT imaging dose were measured using A1SL ion chamber inserted in the phantom with preset geometry. The MVCT scanning average dose for the cylindrical "Cheese" phantom was 2.24 cGy, 1.02 cGy, 0.81 cGy during respectively pitch value (pitch 1, 2, 3 mm) with same number slice (10 slice), and same length's average dose was 2.47 cGy, 1.28 cGy, 0.88 cGy respectively (pitch 1, 2, 3 mm). Two major parameters, the assigned pitch numbers and scanning length, where the most important impacts to the dose variation. The MVCT dose was inversely proportional to the CT pitch value. The results may provide a reliable guidance for proper planning design of the scanning region, which is valuable to help minimize the extra dose to patient. Questionnaires were distributed to Radiology departments at hospitals with 300 sickbeds throughout the Pohang region of North Gyeongsang Province concerning awareness and performance levels of infection control. The investigation included measurements of the pollution levels of imaging equipment and assistive apparatuses in order to prepare a plan for the activation of prevention and management of hospital infections. The survey was designed to question respondents in regards to personal data, infection management prevention education, and infection management guidelines.

The using of megavoltage computed tomography in image-guided brachytherapy for cervical cancer: a case report

  • Tharavichitkul, Ekkasit;Janla-or, Suwapim;Wanwilairat, Somsak;Chakrabandhu, Somvilai;Klunklin, Pitchayaponne;Onchan, Wimrak;Supawongwattana, Bongkot;Galalae, Razvan M.;Chitapanarux, Imjai
    • Radiation Oncology Journal
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    • v.33 no.2
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    • pp.155-159
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    • 2015
  • We present a case of cervical cancer treated by concurrent chemoradiation. In radiation therapy part, the combination of the whole pelvic helical tomotherapy plus image-guided brachytherapy with megavoltage computed tomography of helical tomotherapy was performed. We propose this therapeutic approach could be considered in a curative setting in some problematic situation as our institution.