Conformal electron beam radiotherapy using custom-made step bolus for postmastectomy chest wall irradiation: An institutional experience

Background: Postmastectomy radiation (PMRT) to the chest wall using electron beam treatment with uniform bolus was practiced at our institution. The planning target volume (PTV) included the chest wall and the internal mammary nodes (IMN) along with supraclavicular nodal regions. The varying thickness of the postmastectomy chest wall and the varying position of the IMN resulted in dose inhomogeneity in the PTV. In addition, there was the risk of increased lung and cardiac doses. In this prospective study, we report the making of a custom-made bolus using dental wax called “step bolus.” Materials and Methods: From March 2010 to January 2011, 167 patients received PMRT. As conformal photon plans were not acceptable in 48 patients, they were treated with single energy electrons and custom-made bolus. Results: Addition of the step bolus improved dose distribution to the PTV reduced the mean lung dose %, the mean heart dose % and lung dose (D10, D20, D30, D50, and D70). Forty-seven patients had Grade 2, and one patient had Grade 3 skin toxicity. Acute symptomatic radiation pneumonitis was observed in one patient. At 5 years, 29 patients were alive with a median follow-up of 32 months and no local recurrences were observed. One patient died of myocardial infarction unrelated to treatment, one patient did not come for follow-up, 22 patients had systemic metastases, and 24 patients were disease free. Conclusion: A custom-made step bolus using dental wax can be used for tissue compensation in electron beam therapy with resulting good local disease control and acceptable toxicity.

Study of Acute Myelocytic Leukemia Patient Treatment That Used Total Skin Electron Beam / 의학물리

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is 60 degrees around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.

Study of Acute Myelocytic Leukemia Patient Treatment That Used Total Skin Electron Beam / 의학물리

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is 60 degrees around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.

High Energy Electron Beam Therapy for Epithelial Skin Cancers of the Head and Neck / 대한피부과학회지

BACKGROUND: High energy electron beam therapy is an excellent modality for treating epithelial skin cancers with high local tumor control, good cosmesis and low complication. OBJECTIVE: Our purpose was to determine the local control rate, complication rate and cosmesis of electron beam therapy with histopathologically confirmed epithelial skin cancers. METHODS: A total of 23 consecutively treated, biopsy proven epithelial skin cancers of the head and neck treated with electron beam therapy were retrospectively analyzed to determine the rate of local control, radiotherapy reaction and cosmesis. RESULTS: Seventy percent of patients received electron beam therapy after biopsy only and 26% received electron beam therapy following surgical excision with pathologically positive margins or insufficient excision. The overall local tumor control rate was 87%. Patients with basal cell carcinoma had a 89% overall control rate; patients with squamous cell carcinoma had 80%. Excellent or good cosmesis was achieved in 96%. Side effects were mild and self-limiting. CONCLUSION: Electron beam therapy remains an excellent treatment modality for epithelial skin cancer and offers excellent cosmesis.

Three cases of epithelial skin cancer treated with high energy electron beam / 대한피부과학회지

Higt energy electron beam therapy is a method which is used for the treatment of superficial tumors (less than 5 cm deep) with a characteristically sharp drop-off in dose beyond the tumor. This method offers distinct advantages in dose uniformity and in minimizing the dose to deeper tissues. We report herein three cases of epithelial skin cancer treated with high energy electron beam. The first patient was a 79-year-old male who had primary basal cell carcinoma(BCC) on the right lateral canthus. The second patient was a 67-year-old male who had recurreiit BCC on the right cheek. Both of them received electron beam therapy on the lesion and there were no clinical relapse signs over 1 year. The third patient was a 46-year-old male who had squamous cells, carcinoma on the lower lip. He also received electron beam therapy on the lesion, but it recurred.

Dosimetry for Total Skin Electron Beam Therapy in Skin Cancer / 대한치료방사선과학회지

Increasing frequency of skin cancer, mycosis fungoides, Kaposi's sarcoma etc, it need to treatment dose planning for total skin electron beam (TSEB) therapy. Appropriate treatment planning for TSEB therapy is needed to give homogeneous dose distribution throughout the entire skin surface. The energy of 6 MeV electron from the 18 MeV medical linear accelerator was adapted for superficial total skin electron beam therapy. The energy of the electron beam was reduced to 4.2 MeV by a 0.5cm x90cm x180cm acryl screen placed in a feet front of the patient. Six dual field beam was adapted for total skin irradiation to encompass the entire body surface from head to toe simultaneously. The patients were treated behind the acryl screen plate acted as a beam scatterer and contained a parallel-plate shallow ion chamber for dosimetry and beam monitoring. During treatment, the patient was placed in six different positions due to be homogeneous dose distribution for whole skin around the body. One treatment session delivered 400 cGy to the entire skin surface and patients were treated twice a week for eight consecutive weeks, which is equivalent to TDF value 57. Instrumentation and techniques developed in determining the depth dose, dose distribution and bremsstrahlung dose are discussed.