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Yasuyuki Akine

Publications and source records attributed to Yasuyuki Akine.

At least 19 recordsLinked to original sources
PubMed2006

Determination of gate-on and -off timing in respiration-gated radiotherapy.

The purpose of this study was to develop an efficient method of determining gate-on and -off timing in respiration-gated radiotherapy. Gate-on and -off timing in a breathing cycle were defined as the respiratory signal level for the start of irradiation (Ls) in the expiration phase and that for the end of irradiation (Le) in the inspiration phase, respectively. Thirty subjects participated in this study. The diaphragm was used as the tracking target, and time-dependent changes in the position of the target were measured together with those in the respiratory signal level. For each subject, the following maps were created by varying the combination of Ls and Le: absolute target displacement (ATD) map, relative target displacement (RTD) map, and gate-on duty cycle (GDC) map. By classifying respiratory signal waveforms, three respiratory types were derived (A: the length of end-expiration level >40% of a breathing cycle, B: the length of end-expiration level 20% of a breathing cycle, and C: the length of end-expiration level <or=40% and that of end-inspiration level <or=20% of a breathing cycle). For each respiratory type, average RTD and GDC maps were created. We presented an algorithm to obtain the optimal Ls and Le using the RTD (or ATD) and GDC maps, and this algorithm was verified by demonstrating that, in determining Ls and Le for a subject, the average RTD and GDC maps corresponding to the subject's respiratory type could be used effectively.

Adult↗
PubMed2006

Proton beam therapy for hepatocellular carcinoma with limited treatment options.

BACKGROUND: The authors conducted a retrospective review to define the usefulness of proton beam therapy for patients who had hepatocellular carcinoma (HCC) with limited treatment options. METHODS: Twenty-one patients with HCC for whom other treatment modalities either were contraindicative or were unfeasible because of coexisting diseases and unfavorable conditions received proton beam therapy. Four patients had renal failure, 2 patients had severe heart disease, 9 patients had severe cirrhosis, 1 patient had aplastic anemia, 1 patient had a dissecting abdominal aortic aneurysm before treatment, and 4 patients had bleeding tendency or unresectable tumors. Moreover, 2 of the latter 4 patients were allergic to iodine, and 2 other patients were unable to be catheterized for transcatheter arterial chemoembolization. Hepatic tumors were solitary in 14 patients and multiple in 7 patients, and the tumors ranged in greatest dimension from 25 mm to 100 mm (median, 40 mm). No patient had regional lymph node or distant metastasis. Total doses of 63 grays (Gy) to 84 Gy (median, 73 Gy) in 13 to 27 fractions (median, 18 fractions) were used for tumor treatments. RESULTS: All but 1 of the irradiated tumors were controlled at a median follow-up of 3.3 years. The objective response rate was 81%, and the primary site-control rate was 93% at 5 years. Eleven patients had intrahepatic recurrences, and 2 patients had distant metastases in the lungs. Four of 11 patients with intrahepatic recurrences received a second course of proton beam therapy, and all recurrent tumors were controlled. The overall and cause-specific survival rates were 62% and 82% at 2 years, respectively, and 33% and 67% at 5 years, respectively. Grade > or =3 therapy-related toxicities were not observed. CONCLUSIONS: Proton beam therapy was safe and effective for a variety of patients with HCC. The current results suggested that this method was tolerable and effective, even for patients with HCC who had limited treatment options.

Aged↗
PubMed2006

Proton beam therapy for invasive bladder cancer: a prospective study of bladder-preserving therapy with combined radiotherapy and intra-arterial chemotherapy.

PURPOSE: To present outcomes of bladder-preserving therapy with proton beam irradiation in patients with invasive bladder cancer. METHODS AND MATERIALS: Twenty-five patients with transitional cell carcinoma of the urinary bladder, cT2-3N0M0, underwent transurethral resection of bladder tumor(s), followed by pelvic X-ray irradiation combined with intra-arterial chemotherapy with methotrexate and cisplatin. Upon completion of these treatments, patients were evaluated by transurethral resection biopsy. Patients with no residual tumor received proton irradiation boost to the primary sites, whereas patients demonstrating residual tumors underwent radical cystectomy. RESULTS: Of 25 patients, 23 (92%) were free of residual tumor at the time of re-evaluation; consequently, proton beam therapy was applied. The remaining 2 patients presenting with residual tumors underwent radical cystectomy. Of the 23 patients treated with proton beam therapy, 9 experienced recurrence at the median follow-up time of 4.8 years: local recurrences and distant metastases in 6 and 2 patients, respectively, and both situations in 1. The 5-year overall, disease-free, and cause-specific survival rates were 60%, 50%, and 80%, respectively. The 5-year local control and bladder-preservation rates were 73% and 96%, respectively, in the patients treated with proton beam therapy. Therapy-related toxicities of Grade 3-4 were observed in 9 patients: hematologic toxicities in 6, pulmonary thrombosis in 1, and hemorrhagic cystitis in 2. CONCLUSIONS: The present bladder-preserving regimen for invasive bladder cancer was feasible and effective. Proton beam therapy might improve local control and facilitate bladder preservation.

Adult↗
PubMed2006

Repeated proton beam therapy for hepatocellular carcinoma.

PURPOSE: To retrospectively evaluate the safety and effectiveness of repeated proton beam therapy for newly developed or recurrent hepatocellular carcinoma (HCC). METHODS AND MATERIALS: From June 1989 through July 2000, 225 patients with HCC underwent their first course of proton beam therapy at the University of Tsukuba. Of them, 27 with 68 lesions who had undergone two or more courses were retrospectively reviewed in this study. Median interval between the first and second course was 24.5 months (range 3.3-79.8 months). Median total dose of 72 Gy in 16 fractions and 66 Gy in 16 fractions were given for the first course and the rest of the courses, respectively. RESULTS: The 5-year survival rate and median survival period from the beginning of the first course for the 27 patients were 55.6% and 62.2 months, respectively. Five-year local control rate for the 68 lesions was 87.8%. Of the patients, 1 with Child-Pugh class B and another with class C before the last course suffered from acute hepatic failure. CONCLUSIONS: Repeated proton beam therapy for HCC is safe when the patient has a target in the peripheral region of the liver and liver function is Child-Pugh class A.

Adult↗
PubMed2006

Proton beam therapy for hepatocellular carcinoma patients with severe cirrhosis.

BACKGROUND AND PURPOSE: Hepatocellular carcinoma (HCC) patients with severe cirrhosis are usually treated with supportive care because of their poor prognosis. However, the survival of severe cirrhotic patients has recently improved due to advanced treatments. The aim of this study was to define the role of proton beam therapy for HCC patients with severe cirrhosis. PATIENTS AND METHODS: 19 HCC patients with Child-Pugh class C cirrhosis received proton beam therapy. The hepatic tumors were solitary in 14 patients and multiple in five, and the tumor size was 25-80 mm (median 40 mm) in maximum diameter. No patient had regional lymph node or distant metastasis. Total doses of 50-84 Gy (median 72 Gy) in ten to 24 fractions (median 16) were delivered to the tumors. RESULTS: Of the 19 patients, six, eight and four died of cancer, liver failure and intercurrent diseases, respectively, during the follow-up period of 3-63 months (median 17 months) after treatment. A remaining patient was alive with no evidence of disease 33 months after treatment. All but one of irradiated tumors were controlled during the follow-up period. Ten patients had new intrahepatic tumors outside the irradiated volume. The overall and progression-free survival rates were 53% and 47% at 1 year, respectively, and 42% each at 2 years. Performance status and Child-Pugh score were significant prognostic factors for survival. Therapy-related toxicity of grade 3 or more was not observed. CONCLUSION: Proton beam therapy for HCC patients with severe cirrhosis was tolerable. It may improve survival for patients with relatively good general condition and liver function.

Aged↗
PubMed2006

Sequential evaluation of hepatic functional reserve by 99mTechnetium-galactosyl human serum albumin scintigraphy after proton beam therapy: a report of three cases and a review of the literatures.

The treatment strategy for malignant liver tumors should be appropriately determined because post-treatment quality of life greatly depends on the patients' residual hepatic function. In this report, we present three patients with malignant liver tumors treated by proton beam therapy in whom pre- and post-therapeutic hepatic functional reserves were evaluated sequentially for more than a year by 99mTechnetium-galactosyl human serum albumin (99mTc-GSA) scintigraphy. All three patients exhibited the distinctive time course of 99mTc-GSA uptake efficiency, which suggested a transient decline in the ratio of liver activity to heart and liver activity at 15 minutes (LHL15) 3-6 months after proton beam therapy. This change was not in parallel with that expected from a functioning normal liver tissue volume. In a year after proton beam therapy, LHL15 recovered nearly to the pre-treatment level in all three patients. Our observations may be related to the up-regulation of receptor-mediated 99mTc-GSA uptake during hepatic regeneration after proton beam therapy.

Aged↗
PubMed2005

Early determination of uterine cervical squamous cell carcinoma radioresponse identifies high- and low-response tumors.

PURPOSE: To investigate whether early-assessed radioresponse of tumors corresponds with late-assessed radioresponse, which is associated with local disease control in radiotherapy (RT) for cervical cancer. METHODS AND MATERIALS: This prospective study included 12 patients with cervical squamous cell carcinoma treated by RT with or without concurrent cisplatin. Tumor volume was estimated by scheduled magnetic resonance imaging before (preRT), 3 to 4 weeks after (early assessment), and 6 to 7 weeks after (late assessment) RT initiation. Radioresponse was assessed with tumor shrinkage curves based on these volumes. Radioresponse for each tumor was calculated as the slope (day(-1)) of the shrinkage curve by fitting to an exponential equation. RESULTS: Early-assessed radioresponse ranged from 0.001 to 0.106 day(-1) (median, 0.021 day(-1)) and late-assessed radioresponse from 0.009 to 0.091 day(-1) (median, 0.021 day(-1)), with no significant difference between them (p = 0.1191). The early-assessed radioresponse correlated with the late-assessed radioresponse (R(2) = 0.714, p = 0.0005). CONCLUSIONS: Correspondence between early- and late-assessed radioresponse in a series of tumors showing a wide range of radioresponse was not particularly close overall. However, early assessment of radioresponsiveness did seem to be useful for characterizing those tumors with high or low radioresponsiveness.

Adult↗
PubMed2005

Proton beam therapy for hepatocellular carcinoma with portal vein tumor thrombus.

BACKGROUND: Treatment modalities for patients with hepatocellular carcinoma (HCC) who have portal vein tumor thrombus (PVTT) are limited and controversial; furthermore, the prognosis for these patients is extremely poor. The authors conducted a retrospective review to determine the role of proton beam therapy in the treatment of patients who had HCC with PVTT. METHODS: Twelve patients with HCC who had tumor thrombus in the main trunk or major branches of the portal vein (clinical T3-T4N0M0) were treated with proton beam therapy. At the time they received proton beam irradiation, patients ranged in age from 42 years to 80 years (median, 62 years), and their tumors ranged in size from 40 mm to 110 mm (median, 60 mm) in greatest dimension. A total dose of 50-72 gray (Gy) (median, 55 Gy) in 10-22 fractions was delivered to the tumors, including PVTT. RESULTS: All tumors that were treated with proton beam therapy remained controlled at a median follow-up of 2.3 years (range, 0.3-7.3 years). Among 12 patients, 10 patients had new liver tumors outside the irradiated volume 0.1-2.4 years after proton beam therapy, and 3 patients also had distant metastases; consequently, 8 patients died of disease, and 2 patients were salvaged by further therapies. The remaining two patients were alive with no evidence of disease 4.3 years and 6.4 years after proton beam therapy. The progression-free survival rates were 67% at 2 years and 24% at 5 years. The median progression-free survival was 2.3 years. According to the Acute Radiation Morbidity Scoring Criteria (Radiation Therapy Oncology Group), therapy-related toxicity > or = Grade 3 was not observed. CONCLUSIONS: Proton beam therapy for patients with HCC who had PVTT was feasible and effective. It appeared to improve survival and local control significantly for these patients.

Adult↗
PubMed2005

Proton beam therapy for hepatocellular carcinoma: a retrospective review of 162 patients.

PURPOSE: We present results of patients with hepatocellular carcinoma (HCC) treated with proton beam therapy. EXPERIMENTAL DESIGN: We reviewed 162 patients having 192 HCCs treated from November 1985 to July 1998 by proton beam therapy with or without transarterial embolization and percutaneous ethanol injection. The patients in the present series were considered unsuitable for surgery for various reasons, including hepatic dysfunction, multiple tumors, recurrence after surgical resection, and concomitant illnesses. The median total dose of proton irradiation was 72 Gy in 16 fractions over 29 days. RESULTS: The overall survival rate for all of the 162 patients was 23.5% at 5 years. The local control rate at 5 years was 86.9% for all 192 tumors among the 162 patients. The degree of impairment of hepatic functions attributable to coexisting liver cirrhosis and the number of tumors in the liver significantly affected patient survival. For 50 patients having least impaired hepatic functions and a solitary tumor, the survival rate at 5 years was 53.5%. The patients had very few acute reactions to treatments and a few late sequelae during and after the treatments. CONCLUSIONS: Proton beam therapy for patients with HCC is effective, safe, well tolerable, and repeatable. It is the useful treatment mode for either cure or palliation for patients with HCC irrespective of tumor size, tumor location in the liver, insufficient feeding of the tumor with arteries, presence of vascular invasion, impaired hepatic functions, and coexisting intercurrent diseases.

Adult↗
PubMed2005

Real-time monitoring of a digestive tract marker to reduce adverse effects of moving organs at risk (OAR) in radiotherapy for thoracic and abdominal tumors.

PURPOSE: To evaluate the feasibility of real-time monitoring of a fiducial marker in/near the digestive tract and to analyze the motion of organs at risk to determine a reasonable internal margin. METHODS AND MATERIALS: We developed two methods to insert a fiducial marker into/near the digestive tract adjacent to the target volume. One method involves an intraoperative insertion technique, and the other involves endoscopic insertion into the submucosal layer of the normal digestive tract. A fluoroscopic real-time tumor-tracking radiotherapy system was used to monitor the marker. RESULTS: Fourteen markers (2 in the mediastinum and 12 in the abdomen) were implanted intraoperatively in 14 patients with no apparent migration. Seventeen of 20 markers (13/14 in the esophagus, 1/2 in the stomach, and 3/4 in the duodenum) in 18 patients were implanted using endoscopy without dropping. No symptomatic adverse effects related to insertion were observed. The mean/standard deviation of the range of motion of the esophagus was 3.5/1.8, 8.3/3.8, and 4.0/2.6 mm for lateral, craniocaudal and anteroposterior directions, respectively, in patients with intrafractional tumor motion less than 1.0 cm. CONCLUSION: Both intraoperative and endoscopic insertions of a fiducial marker into/near the digestive tract for monitoring of organs at risk were feasible. The margin for internal motion can be individualized using this system.

Abdominal Neoplasms↗
PubMed2005

Clinical results of proton beam therapy for cancer of the esophagus.

PURPOSE: To present the results of proton beam therapy for patients with esophageal cancer. METHODS AND MATERIALS: This study reviewed 46 patients with esophageal cancer who were treated between 1985 and 1998 using proton beams with or without X-rays. All patients had locoregionally confined disease; all but one had squamous cell carcinoma. Of the 46 patients, 40 received combinations of X-rays (median, 48 Gy) and protons (median, 31.7 Gy) as a boost. The median total dose of combined X-ray and proton radiation for the 40 patients was 76.0 Gy (range, 69.1-87.4 Gy). The remaining 6 patients received only proton beam therapy (median, 82.0 Gy; range, 75-89.5 Gy). RESULTS: The 5-year actuarial survival rate for the 46 patients, patients with T1 (n = 23), and those with T2-T4 (n = 23) was 34%, 55%, and 13%, respectively. The 5-year disease-specific survival rate for the 46 patients, those with T1, and those with T2-T4 was 67%, 95%, and 33%, respectively. The 5-year local control rate for patients with T1 and T2-T4 lesions was 83% and 29%, respectively. The site of the first relapse was locoregional for 16 patients and distant organs for 2 patients. CONCLUSION: The results suggest that proton beam therapy is an effective treatment for patients with locally confined esophageal cancer. Additional studies are required to determine the optimal total dose, fractionation schedule, and best combinations of protons and conventional X-rays with or without chemotherapy.

Aged↗
PubMed2005

Monitoring of hepatocellular carcinoma, following proton radiotherapy, with contrast-enhanced color Doppler ultrasonography.

BACKGROUND: We have reported that proton radiotherapy for hepatocellular carcinoma (HCC) is a safe and effective therapeutic option. However, it is difficult to evaluate its effect in certain cases. Recently, it has been reported that the usage of contrast-enhanced color Doppler ultrasonography (CECDU) can improve diagnostic accuracy, both in terms of the presence of hepatic tumor and in the evaluation of treatment. The aim of this study was to determine the usefulness of CECDU in assessing the therapeutic response of HCC treated with proton radiotherapy. METHODS: Twenty-two patients treated with the proton radiotherapy were studied. We inspected HCC lesions by CECDU, before and after the irradiation, over time. The magnitude of blood flow in the HCC was quantified on still images by CECDU. The ratio of the number of color pixels against that of the total number of pixels in the tumor area was defined as the tumor blood flow ratio (TBFR). RESULTS: Immediately after the proton treatment, a transient increase of blood flow in the tumor was recognized in more than half of the patients, while the TBFR was unchanged or decreased in the remaining patients. At longer periods after irradiation, the TBFR in all HCCs gradually decreased, and this reduction of TBFR was statistically significant from 9 months after irradiation. These findings are consistent with those obtained previously by computed tomography (CT) as well as magnetic resonance imaging (MRI). CONCLUSIONS: We propose CECDU as a useful diagnostic option for the evaluation of HCC treated with proton radiotherapy.

Aged↗
PubMed2005

Concurrent proton beam radiotherapy and systemic chemotherapy for the metastatic liver tumor of gastric carcinoma: a case report.

We report a case of a woman with a metastatic liver tumor from gastric carcinoma, who has been successfully treated with concurrent proton beam therapy and systemic chemotherapy. A 76-year-old woman underwent distal gastrectomy with regional lymph node dissection for advanced gastric carcinoma on January 17, 2002. She received five courses of sequential chemotherapy with methotrexate-5-fluorouracil after the surgical resection. A metastatic liver tumor was detected in the caudate lobe of the liver by computed tomography at 6 months after the surgical resection. We employed concurrent proton beam therapy and systemic chemotherapy which consisted of 5-fluorouracil (250 mg/body per day, as a 24-h intravenous injection for 4 weeks) and low dose cisplatin (10 mg/body on days 1-5 every week for 4 weeks). Proton beam therapy targeting the metastatic liver tumor was performed in a daily fraction of 3 Gy, 5 days per week, with a total dose of 66 Gy over 30 days. The tumor disappeared 3 months after the treatment and no recurrence has been observed for 2 years after termination of the treatment. Throughout the entire course of treatment, the patient received injections of granulocyte stimulating factor subcutaneously for grade 3 leukopenia. She never complained of abdominal symptoms, such as epigastralgia, nausea or diarrhea. Liver failure related to proton irradiation has not been observed. This concurrent proton beam radiotherapy with systemic chemotherapy could be an effective treatment modality for metastatic liver tumor from gastric carcinoma.

Adenocarcinoma↗
PubMed2005

Preliminary estimation of treatment effect on uterine cervical squamous cell carcinoma in terms of tumor regression rate: comparison between chemoradiotherapy and radiotherapy alone.

PURPOSE: We preliminarily estimated the treatment effect on cervical cancer in terms of the tumor regression rate (TRR) achieved with chemoradiotherapy and radiotherapy alone. MATERIALS AND METHODS: The study included cervical squamous cell carcinomas treated by radiotherapy alone (n=45) or chemoradiotherapy (concurrent once-a-week cisplatin 30 mg/m2, n=13). Tumors were measured three-dimensionally on pre- and mid-treatment magnetic resonance images. TRR was defined as the slope of the exponential regression curve of tumor volume (day(-1)) on the assumption that tumors regressed exponentially with time. RESULTS: TRR ranged widely (0.004-0.090 day-(-1)) and did not significantly differ between treatment with chemoradiotherapy (median, 0.032 day(-1)) and with radiotherapy alone (median, 0.024 day(-1)) (p = 0.361). TRR > 0.05 day(-1) was seen in four chemoradiotherapy tumors (30.8%) and in six radiotherapy-alone tumors (15.0%) (p = 0.207), whereas TRR < 0.01 day(-1) was seen in no chemoradiotherapy tumors (0.0%) and in five radiotherapy-alone tumors (11.1%) (p = 0.180). TRR for tumors > 5.0 cm in diameter was greater with chemoradiotherapy (n=5) than with radiotherapy alone (n=12) (p = 0.065). CONCLUSION: Although the difference did not reach a statistically significant level, our TRR data suggest that concurrent chemotherapy heightens the radioresponse of large-size cervical cancer.

Adult↗
PubMed2004

Clinical results of proton beam therapy for skull base chordoma.

PURPOSE: To evaluate clinical results of proton beam therapy for patients with skull base chordoma. METHODS AND MATERIALS: Thirteen patients with skull base chordoma who were treated with proton beams with or without X-rays at the University of Tsukuba between 1989 and 2000 were retrospectively reviewed. A median total tumor dose of 72.0 Gy (range, 63.0-95.0 Gy) was delivered. The patients were followed for a median period of 69.3 months (range, 14.6-123.4 months). RESULTS: The 5-year local control rate was 46.0%. Cause-specific, overall, and disease-free survival rates at 5 years were 72.2%, 66.7%, and 42.2%, respectively. The local control rate was higher, without statistical significance, for those with preoperative tumors <30 mL. Partial or subtotal tumor removal did not yield better local control rates than for patients who underwent biopsy only as the latest surgery. CONCLUSION: Proton beam therapy is effective for patients with skull base chordoma, especially for those with small tumors. For a patient with a tumor of <30 mL with no prior treatment, biopsy without tumor removal seems to be appropriate before proton beam therapy.

Adolescent↗
PubMed2004

Correlation between the respiratory waveform measured using a respiratory sensor and 3D tumor motion in gated radiotherapy.

PURPOSE: The purpose of this study is to investigate the correlation between the respiratory waveform measured using a respiratory sensor and three-dimensional (3D) tumor motion. METHODS AND MATERIALS: A laser displacement sensor (LDS: KEYENCE LB-300) that measures distance using infrared light was used as the respiratory sensor. This was placed such that the focus was in an area around the patient's navel. When the distance from the LDS to the body surface changes as the patient breathes, the displacement is detected as a respiratory waveform. To obtain the 3D tumor motion, a biplane digital radiography unit was used. For the tumor in the lung, liver, and esophagus of 26 patients, the waveform was compared with the 3D tumor motion. The relationship between the respiratory waveform and the 3D tumor motion was analyzed by means of the Fourier transform and a cross-correlation function. RESULTS: The respiratory waveform cycle agreed with that of the cranial-caudal and dorsal-ventral tumor motion. A phase shift observed between the respiratory waveform and the 3D tumor motion was principally in the range 0.0 to 0.3 s, regardless of the organ being measured, which means that the respiratory waveform does not always express the 3D tumor motion with fidelity. For this reason, the standard deviation of the tumor position in the expiration phase, as indicated by the respiratory waveform, was derived, which should be helpful in suggesting the internal margin required in the case of respiratory gated radiotherapy. CONCLUSION: Although obtained from only a few breathing cycles for each patient, the correlation between the respiratory waveform and the 3D tumor motion was evident in this study. If this relationship is analyzed carefully and an internal margin is applied, the accuracy and convenience of respiratory gated radiotherapy could be improved by use of the respiratory sensor.Thus, it is expected that this procedure will come into wider use.

Esophageal Neoplasms↗