Publications (11) View all
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Article: Hypofractionated Stereotactic Radiotherapy with the Hypoxic Sensitizer AK-2123 (Sanazole) for Reirradiation of Brain Metastases: A Preliminary Feasibility Report.
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ABSTRACT: Reirradiation is a challenging field in the treatment of recurrent brain metastases. Because of the elevated risk of radiation toxicity due to previous irradiation, only a limited dose is prescribed. To enhance radiosensitivity, in the present analysis six patients received hypofractionated stereotactic radiotherapy (hSRT) with daily oral administration of the hypoxic sensitizer AK-2123 (sanazole) for progressive brain metastases after previous radiotherapy. The patients received daily oral administration of 1.0 g/day sanazole up to 2 h before radiotherapy. Three partial and three stable responses were observed, with no sanazole-related toxicity, except for a case of mild nausea. Brain failure with subsequent death occurred in one patient. The other patients maintained good performance status until disease progression in other lesions. hSRT with a hypoxic radiation sensitizer appears to have the potential to enhance the efficacy of radiotherapy.Anticancer research 04/2013; 33(4):1773-6. · 1.73 Impact Factor -
Article: Feasibility Trial for Daily Oral Administration of the Hypoxic Sensitizer AK-2123 (Sanazole) in Radiotherapy.
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ABSTRACT: To examine the feasibility of daily oral administration of the hypoxic tumor radiation sensitizer, sanazole (AK-2123). We analyzed the toxicity associated with 44 treatments of 42 patients, who received daily oral administration of 1 g/day sanazole (level A, 1-9g, 12 treatments; Level B, 10 g, 33 treatments) 2 h before radiotherapy. Eligibility criteria were as follows: Patients who were unable to receive standard treatment because of older age and/or fragile status and/or refractory disease. Five patients with advanced tumors treated with pre- or postoperative adjuvant radiotherapy were also included. Toxicity was assessed during 44 treatment sessions. Eight patients (18%) showed sanazole-related paresthesia in the extremities, similar to the rate (15%) reported in a preceding multi-institutional international phase III study, which used intravenous administration. No sanazole-related toxicity rated grade 3 or higher was observed. Forty out of the 44 treatment sessions (91%) were completed. This study validates the feasibility of daily oral administration of sanazole. Further studies to establish suitable applications are warranted.Anticancer research 02/2013; 33(2):643-6. · 1.73 Impact Factor -
Article: Evaluation of dosimetry and excess seeds in permanent brachytherapy using a modified hybrid method: a single-institution experience.
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ABSTRACT: Permanent prostate brachytherapy is frequently performed worldwide, and many studies have demonstrated its favorable outcomes. Implant seeds used in this procedure contain a precise amount of radionuclide and are completely sealed. Because these seeds are not manufactured in Japan, they are expensive (6300 yen per seed) and therefore need careful management as a radioisotope. The proper implantation technique requires considerable procedure time, good dosimetric outcomes and simple radioactive isotope management. To evaluate the modified hybrid interactive technique based on these considerations, we assessed 313 patients who underwent hybrid interactive brachytherapy without additional external beam radiotherapy. We evaluated the duration of the procedure, dosimetric factors and the total number of excess seeds. The dosimetric results from computed tomography on Day 30 of follow-up were: 172 Gy (range 130-194 Gy) for pD90, 97.8% (83.5-100%) for pV100, 54.6% (27.5-82.4%) for pV150, 164 Gy (120-220 Gy) for uD90, 194 Gy (126-245 Gy) for uD30, 210 Gy (156-290 Gy) for uD5, 0.02 ml (0-1.2 ml) for rV100 and 0 ml (0-0.2 ml) for rV150. The number of excess seeds was determined by subtracting the number of implanted seeds from the expected number of seeds calculated from previously proposed nomograms. As per our method, nine excess seeds were used for two patients, whereas using the nomograms, the number of excess seeds was approximately eight per patient. Our modified hybrid interactive technique reduced the number of excess seeds while maintaining treatment quality.Journal of Radiation Research 01/2013; · 1.68 Impact Factor -
Article: Assessment of radiation dermatitis using objective analysis for patients with breast cancer treated with breast-conserving therapy: influence of body weight.
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ABSTRACT: To evaluate the effect of patient factors on radiation dermatitis for patients with breast cancer who underwent postoperative radiotherapy after breast-conserving surgery. The study population comprised 87 patients who underwent breast-conserving surgery followed by 50 Gy/25 fractions (median) of radiotherapy with or without boost radiation (10 Gy/5 fractions). We examined their treated and contralateral breast skin color by use of an objective analyzer, and expressed findings as L, a, b ratios by dividing by pre-RT values. Next, we examined correlation between patient factors (age, height, body weight, and body mass index, BMI) and change of L and a values by use of correlation coefficients. Radiation therapy caused changes in a and L ratios (p < 0.0001) but not in b ratio. The a ratio (reddish) increased 1.4-fold and peaked after radiotherapy. The L ratio (darkening) decreased by 10 % and reached a minimum value between completion of radiotherapy and 1 month after treatment. Although, age and height did not affect Δ value, body weight and BMI correlated significantly with Δa value (p = 0.0012 and 0.0017) not with ΔL value. Body weight and BMI predict degree of radiation dermatitis, and more reddish dermatitis was observed for heavier patients than for their lighter counterparts.Japanese journal of radiology 04/2012; 30(6):486-91. · 0.65 Impact Factor -
Article: Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract.
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ABSTRACT: To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise. We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan. The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm3 (range, 7.17-14.3 cm3) and 1.99 for pituitary adenoma, and 6.86 cm3 (range 6.05-14.6 cm3) and 2.41 for meningioma. PTV volume was 10.1±1.74 cm3 for group 1 with a margin of 1-2 mm around the CTV (n=3) and 9.28±1.8 cm3 (p=0.51) for group 2 with no margin (n=7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1±3.26 cm3) than group 2 (6.91±0.7 cm3, p=0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring. Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract.Radiation Oncology 01/2011; 6:10. · 2.32 Impact Factor
