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ABSTRACT: A retrospective analysis was performed with emphasis on the patterns of recurrence, latent period, and prognosis in patients with cervical squamous cell carcinoma of the uterus treated with definitive radiation therapy alone. Late recurrence, which was observed more than 5 years after the initial radiation therapy, was finally focused on and discussed.
Between 1976 and 1994, 256 patients with squamous cell carcinoma of the uterine cervix without hematogenous metastasis were treated with definitive radiation therapy alone. The patients were staged as follows according to the FIGO classification: 26 in Stage I, 56 in Stage II, 124 in Stage III, 28 in Stage IVa, and 22 in Stage IVb. All the patients were treated with external beam irradiation and low-dose-rate intracavitary brachytherapy.
A total of 74 patients had recurrence. The recurrence appeared in 67 cases (90.5%) within 5 years. Metastasis to para-aortic and/or supraclavicular nodes developed later than other types of recurrence. Among patients with lymphogenous metastasis, there were more 5-year survivors after recurrence than with other types of recurrence. Patients with early recurrence, within 2 years of the initial therapy, had a worse prognosis than those with recurrence more than 2 years after treatment. Seven patients (2.7%) in all developed late recurrence more than 5 years after the treatment. The first site of recurrence was an abdominal para-aortic or supraclavicular node in all patients, excluding one patient who developed intrapelvic lymph node metastasis. Six patients had pelvic node metastasis detected with lymphangiography at the initial treatment. Median survival after late recurrence was 16.0 months. Two of 7 patients survived more than 3 years after secondary radiation therapy, and the remainder died of recurrent disease.
Patients with para-aortic and/or supraclavicular node metastasis that developed late after the initial treatment are more likely to survive due to secondary radiation therapy. Careful follow-up is emphasized for long-term survivors.
International Journal of Radiation OncologyBiologyPhysics 09/2001; 50(5):1136-44. · 4.11 Impact Factor
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ABSTRACT: To evaluate definitive radiation therapy delivering doses in excess of 60 Gy for elderly patients aged 75 years or over with non-small cell lung cancer (NSCLC).
The treatment results for 97 patients aged 75 years or older (mean age 78 years; elderly group) with inoperable or unresectable NSCLC were retrospectively analyzed and compared with those for 206 patients younger than 75 year old (mean age 64 years; younger group). The elderly patients were classified into two groups; 67 patients aged 75-79 years (the elderly A) and 30 patients aged 80 years or older (the elderly B). Most of all patients were treated with a total dose of 60 Gy or more in 2 Gy daily standard fractionation.
The overall 2 and 5 year survival rates were 32 and 13% for the elderly A group, and 28 and 4% for the elderly B group, respectively, compared with 36 and 12% for the younger group. There was not a statistically significant difference in survival rates among three groups. In stage I-II NSCLC patients there was also no significant difference in survival curves among the three groups. In patients with stage III disease, however, the survival curve of the elderly B was inferior to those of the younger group and the elderly A group, although the difference was not statistically significant. After the treatment the deterioration rate of the performance status was only 5% in the younger group and 8% in the elderly group. Only three younger and two elderly patients died of late pulmonary insufficiency associated with high-dose irradiation to the proximal bronchus. No other treatment-related event was observed except for mild acceptable acute complications in the elderly groups.
Definitive radiation therapy is recommended to the elderly aged 75 years or older with inoperable or unresectable NSCLC, especially early stage disease, as an acceptable choice of treatment.
Lung Cancer 05/2001; 32(1):81-8. · 3.43 Impact Factor
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ABSTRACT: We report a case of small cell lung cancer whose initial presentation was a solitary brain metastasis. On chest radiography the primary tumor was unclear and only detected by bronchofiberscopy. A small single pulmonary metastasis was noted in the right lower lobe. Subtotal resection and external irradiation were applied to the brain tumor and external irradiation was applied to the lung. Concurrently one course of systemic chemotherapy was administered. The tumors in the brain and lung had disappeared by the end of the treatment. The patient has been alive and well for 5 years without recurrence.
Japanese Journal of Clinical Oncology 04/2001; 31(3):116-8. · 1.78 Impact Factor
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ABSTRACT: Radiation therapy is the first choice of treatment for most of the early squamous cell carcinoma of the head and neck. Conventional radiotherapy however, contributes to the high local control rates only for carcinoma of the glottic larynx and the nasopharynx. Squamous cell carcinoma of the other sites cannot be sterilized easily only by external beam radiation therapy alone. Chemoradiotherapy, conformal three-dimensional radiotherapy and multi-daily fractionation are introduced clinically to improve local control and/or survival for radioresistant tumor. In this review, consensus report of radiation therapy for carcinoma of the larynx and pharynx, which was reached an agreement in JASTRO meeting in 1998, is introduced. The role of radiation therapy in the management of head and neck cancer in present and near future is also discussed.
Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 02/2001; 61(1):10-6.
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ABSTRACT: We examined the best way to combine recently developed radiofrequency intracavitary hyperthermia with simultaneous high dose-rate intracavitary brachytherapy in an original experimental model. Temperature distribution was measured with an experimental phantom which was immersed in a water bath with the temperature controlled at 37 degrees C. Radiation dose distribution was calculated with a treatment-planning computer. Cell survival was measured by colony assay with HeLa-TG cells in vitro. Radiation dose response at 1 - 7 Gy and time response with hyperthermia in the range of 40 - 46 degrees C were estimated. Radiation dose-response curves in simultaneous treatment with hyperthermia for 30 min at 37 to 46 degrees C were estimated and the surviving fractions in combined treatment were plotted against temperature. For intracavitary radiation alone, cell survival rates increased with increasing distance from the source. For intracavitary hyperthermia alone, the maximum temperature was observed at a depth of 13 mm from the surface of the applicator under suitable treatment conditions. Homogeneous cell killing from the surface of the applicator to a tumor depth of 13 mm was observed under a specific treatment condition. Our experimental model is useful for evaluating the best simultaneous combined treatment.
Japanese journal of cancer research: Gann 02/2001; 92(1):95-102.
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ABSTRACT: It has been suggested that the p53 tumor suppressor gene regulates the radiosensitivity in human malignancies after irradiation; however, in cervical carcinoma, the role of the p53 gene is still unclear because of inactivation of functional p53 by infection with human papillomavirus (HPV). The objective of this study was to clarify the effects of p53 status and HPV infection on the clinical outcome of patients with cervical carcinoma after undergoing radiation therapy.
Fifty-two patients with International Federation of Gynecology and Obstetrics Stage IIIB squamous cell carcinoma of the cervix who received radiation therapy alone were reviewed. The combination of external beam irradiation therapy and three sessions of intracavity brachytherapy irradiation was performed for all patients. Genomic DNA extracted from paraffin embedded tissues was examined for HPV types 16, 18 and 33 by the polymerase chain reaction (PCR) method and for p53 status by PCR-single-strand conformation polymorphism (PCR-SSCP) technique. The effects of HPV infection, p53 status, and other parameters on clinical outcome were investigated by univariate analysis.
HPV-DNA was detected in 40 patients (76.9%), and 14 patients (26.9%) had mutations of the p53 gene in the study. There was a significant correlation between the existence of HPV and p53 status (P < 0.001). Mutations of the p53 gene were detected in 6 of 12 patients (50%) who had local recurrent tumors, whereas p53 were wild type in 32 of 40 patients (80%) who achieved local control. The p53 mutation had a significant correlations with local tumor recurrence. Furthermore, p53 status caused statistical significant differences in the curves of the recurrence free survival rate and local control rate as determined by the log rank test (P = 0.02 and P = 0.03, respectively). Conversely, no obvious correlation with any clinical outcome for patients with cervical carcinoma was found concerning HPV infection.
It is possible that the p53 gene may be used as a predictive factor in radiation therapy for patients with Stage IIIB squamous cell carcinoma of the cervix.
Cancer 01/2001; 91(1):80-9. · 4.77 Impact Factor
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ABSTRACT: The radiosensitizing effects of caffeine on two rat yolk sac tumor cell lines with a different p53 status were investigated. A reduction of radiation-induced G(2) arrest was caused by caffeine at a concentration of 2 mM in both cell lines. The reduction of survival was observed in a combination of radiation and 2 mM caffeine only in a lower radiation dose range, but not in a higher dose range in NMT-1 with a wild type p53. Radiosensitization of caffeine was recognized even in a higher dose range for cells with a mutant-type p53. Apoptosis, which was not prominent after irradiation alone or caffeine treatment alone, was induced by irradiation in combination with caffeine in cells with a mutant-type p53 through a p53-independent pathway.
Cancer Letters 06/2000; 152(2):157-62. · 4.24 Impact Factor
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ABSTRACT: Radiation therapy(RT) has been frequently used for patients with inoperable or unresectable non-small cell lung cancer(NSCLC). In our series of NSCLC patients without progression of disease at the end of two years after RT, the majority of squamous cell carcinoma patients were alive well after 5 years from RT. On the other hand, half of adenocarcinoma patients had distant failures later. The recent data have indicated that the prognosis for selected favorable patients with unresectable disease will be improved by systemic chemotherapy combined with RT. Furthermore recent innovations in RT have shown promise in the treatment of NSCLC, especially squamous cell carcinoma. For future improvement of the treatment results of NSCLC, it is important that the role of RT be established.
Nippon rinsho. Japanese journal of clinical medicine 06/2000; 58(5):1093-7.
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ABSTRACT: The purpose of this study was to profile cervical squamous cell carcinoma in elderly patients undergoing radiation therapy and to study the treatment outcome and side effects of therapy.
A retrospective analysis was carried out from the records of 380 patients with squamous cell carcinoma of the uterine cervix who had been given radiation therapy between 1970 and 1994. The patients were divided into three age groups: under 70 years (youngest group; n = 215), 70 to 79 years (intermediate group; n = 124), and 80 years or older (oldest group; n = 41). Radiation therapy was performed by a combination of external beam therapy and three brachytherapy fractions using low-dose-rate sources.
The 5-year overall survival rates in the youngest, intermediate, and oldest groups were 58, 50, and 33%, respectively, while cause-specific survival rates were 68, 70, and 65%, respectively. For the patients with stage III, the 5-year overall survival rates in the youngest, intermediate, and oldest groups were 59, 48, and 36%, respectively, while cause-specific survival rates were 72, 70, and 70%, respectively. There was no statistical significance in the 5-year intrapelvic recurrence rates among the three groups. Grade 3 or 4 complications occurred in 6.5% of the youngest, 11.3% of the intermediate, and 7.3% of the oldest groups.
Radiation therapy with external beam combined with three fractions of low-dose-rate brachytherapy proved both highly effective and safe for senior patients with cervical squamous cell carcinoma.
Gynecologic Oncology 05/2000; 77(1):116-20. · 3.89 Impact Factor
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ABSTRACT: In order to investigate the role of potentially lethal damage repair (PLDR) in cellular radiosensitivity, PLDR and its inhibitory effect by caffeine was examined. In addition, cell cycle distribution was also examined.
Two rat yolk sac tumor cell lines, NMT-1 and NMT-1R, with different radiosensitivities in vitro were used. The capacity for PLDR was examined using confluent-phase cells, and evaluated by calculating the recovery ratio. Inhibitory effect of caffeine on PLDR was examined with doses of 1, 5 and 10 mM.
The capacity of PLDR in two cell lines reflected radiosensitivity. The recovery ratio after irradiation of 5 Gy was 2.8 in the radiosensitive NMT-1 and 5.2 in the radioresistant NMT-1R, and recovery reached its peak level at 6 h in both cell lines. The degree of inhibition of PLDR was weaker in NMT-1R than that in NMT-1 at the same dose level, and was correlated with reduction of G2-arrested cells by caffeine.
The results of this study suggest that the capacity of PLDR may be one of the determinant factors for radiosensitivity in the two cell lines used, and the inhibitory effect of caffeine on PLDR was in part attributable to the modification of the cell cycle progression.
Cancer Letters 01/2000; 147(1-2):199-206. · 4.24 Impact Factor
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ABSTRACT: The outcome of limited field irradiation for medically inoperable patients with peripheral stage I non-small cell lung cancer (NSCLC) was analyzed to discuss the elective irradiation of regional lymph nodes. From 1976 through 1994, 36 patients with peripheral stage I NSCLC were treated with definitive radiation therapy (RT) alone at Gunma University hospital. The total dose ranged from 60 to 81 Gy with a 2 Gy-daily standard fractionation, although only one patient received 48 Gy. Ten patients received elective irradiation of the regional lymph nodes with a total dose of 40 Gy or more. The overall response rate was 97% with 31% complete responses. The overall survival rates at 3 and 5 years were 42 and 23%, and disease-specific survival rates were 56 and 39% at 3 and 5 years, respectively. In 26 patients without the elective regional irradiation, disease-specific survival rates at 3 and 5 years were 53 and 40%, respectively, whereas they were 64 and 39% in 10 patients with the regional nodal irradiation. The cumulative 5-year local progression rate was 28%, and the overall progression rate was 60% at 5 years. Four patients had a local recurrence as the only site of initial tumor progression. Combined local and regional progression was seen in two patients, and one patient had a local recurrence in combination with distant metastasis. Twelve patients had distant failure without evidence of local or regional progression. Only one patient without regional nodal irradiation developed an isolated regional failure. No patient had serious complications related to RT. High-dose limited field RT is justified for medically inoperable patients with peripheral stage I NSCLC. The regional nodal irradiation can be omitted in these pulmonary compromised patients because of the low regional relapse rate. Dose-escalation by a conformal RT with a small target volume can be expected to provide a better local control rate and better survival.
Lung Cancer 01/2000; 26(3):137-42. · 3.43 Impact Factor
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ABSTRACT: The purpose of this paper is to determine the relationship between the response to radiation and the appearance of apoptosis and micronuclei with Trp53 protein in murine tumors after irradiation. Two murine tumors, EL4, which was derived from a mouse lymphoma, and FM3A, which was derived from a mouse mammary carcinoma, were locally irradiated with 15 Gy and sections were stained with H&E and an anti-Trp53 antibody. The response to radiation was greater in EL4 tumors than in FM3A tumors. The frequency of apoptotic cells in EL4 tumors was 6.1 +/- 1.2% at time zero, reached a peak of 36.3 +/- 3. 8% at 6 h, and then decreased with time through 72 h to 2.5 +/- 1.5% after 15 Gy irradiation. In FM3A tumors, no apoptotic cells were detected at 0, 1, 3, 6 or 24 h after exposure. At 48 and 72 h, the frequency was only 3.0 +/- 0.6% and 1.3 +/- 0.3%. Apoptotic cells increased significantly at 3, 6 and 24 h after irradiation in EL4 tumors (P < 0.008) and at 48 and 72 h in FM3A tumors (P < 0.006). The frequency of Trp53-positive cells was 17.9 +/- 2.2 and 15.2 +/- 2.3% at time zero in EL4 and FM3A tumors, respectively, increased to 74.5 +/- 4.5% in EL4 cells (P = 0.001), and increased to 33.9 +/- 1. 1% in FM3A cells (P = 0.005) 1 h after irradiation. Trp53-positive micronuclei appeared in cells in both tumors from 24 to 72 h after irradiation. The frequency of Trp53-positive micronuclei was 3.8 +/- 0.5 and 13.5 +/- 1.3% at 24 h in EL4 and FM3A tumors, respectively, and gradually decreased by 72 h. After exposure to 15 Gy, Trp53-positive micronuclei increased significantly in FM3A tumors compared to EL4 tumors at both 24 and 48 h (P < 0.02). The frequency of these micronuclei increased with increasing dose in FM3A tumors, and the difference between these percentages after 3 Gy and after 5, 10 and 15 Gy was significant (P < 0.02). Many apoptotic cells were observed in the radiosensitive EL4 tumor after irradiation. Death by apoptosis may be related to an early response to radiation in these tumors. The appearance of micronuclei may be an important mechanism of cell death in FM3A tumors in which no apoptosis was induced.
Radiation Research 12/1999; 152(5):462-7. · 2.68 Impact Factor
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ABSTRACT: A case of giant cell tumor of the thoracic spine simulating mediastinal neoplasm was identified on plain films, CT scans, MR images, and with scintigraphy. CT showed a hypervascular soft-tissue mass with shell-like calcification in the right upper mediastinum. MR imaging showed a collapse of the T1 vertebral body and a mass extending to the mediastinum. The mass had a low signal on T1-weighted MR images and a predominantly high signal on T2-weighted images with heterogeneity. Technetium-99m methylene diphosphonate bone scintigraphy showed intense uptake in both the T1 and marginal parts of the mediastinal mass. There was no accumulation of gallium-67 citrate, but 18-fluorine fluorodeoxyglucose positron emission tomography showed marked uptake. The variation in these imaging findings played an important role in the differential diagnosis of this uncommon mediastinal mass.
American Journal of Neuroradiology 11/1999; 20(9):1723-6. · 2.93 Impact Factor
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ABSTRACT: The differences between two rat yolk sac tumor cell lines, which are of the same origin but differ in their response to irradiation, in thermal sensitivity and development of thermotolerance were investigated. A radiosensitive cell line NMT-1 is consistently less heat sensitive than the radioresistant cell line NMT-1R. The thermotolerances in NMT-1 and in NMT-1R preheated at 43 degrees C for 30 min, respectively, reached peaks at 6 h and at 12 h, but did not completely disappear at 48 h. Thermotolerance with a good correlation between both cell lines with HSP70 accumulation was observed in a different time course after a primary heating.
Cancer Letters 09/1999; 142(2):195-200. · 4.24 Impact Factor
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ABSTRACT: To investigate cell killing by means of low dose-rate irradiation (LDRI) combined with concurrent mild hyperthermia and to determine the effect of low-dose caffeine on this combination treatment.
Human lung adenocarcinoma cells, LK87, were treated with LDRI (50 cGy/h) in combination with mild hyperthermia at 41 degrees C and low-dose caffeine (1 mM). Cell survival was estimated by clonogenic assay. Flow-cytometry was performed with PI staining using FACScan. Heat-shock protein (HSP72/73) was measured by the Western blotting method. All treatments were simultaneously performed for up to 48 h (24 Gy).
LDRI cytotoxicities were enhanced by hyperthermia at 41 degrees C. D0 calculated from the dose-response curve for LDRI combined with 41 degrees C was 3.46 Gy whereas it was 6.55 Gy for LDRI alone. The survival curve for LDRI +41 degrees C demonstrated no chronic thermotolerance up to 48 h. For LDRI + simultaneous low-dose caffeine, cell killing was also enhanced, where D0 was 3.38 Gy at 37 degrees C. Radiosensitization caused by caffeine was enhanced by combination with simultaneous mild hyperthermia at 41 degrees C, where D0=1.78 Gy. Cell cycle analysis demonstrated remarkable G2 and mild G1 arrest for LDRI alone, but only G1 arrest was observed for LDRI combined with 41 degrees C and for LDRI combined with caffeine. Strong and early G1 arrest was observed in the treatment with LDRI + caffeine at 41 degrees C. The amount of HSP72/73 in the combination of LDRI with caffeine at 41 degrees C was less than that at 41 degrees C alone.
LDRI cytotoxicity was enhanced by non-lethal hyperthermia. Low dose caffeine produced further cell killing in the combination of LDRI with mild hyperthermia.
International Journal of Radiation Biology 07/1999; 75(6):739-45. · 2.28 Impact Factor
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ABSTRACT: To investigate the clinical efficacy of radiation therapy for cancer in patients aged 90 years or older.
Cancer cases in 32 patients (11 men, 21 women) aged 90 years or older who underwent radiation therapy in 1970-1997 were retrospectively analyzed. The mean patient age was 92.2 years, with a range of 90-98 years. Head and neck cancer (n = 14 [44%]) and skin cancer (n = 6 [19%]) were the most common.
Eleven (79%) of the 14 patients with head and neck cancer were treated with curative intent. Radiation response without any severe complication was observed in nine (90%) of the 10 patients with head and neck cancer treated with curative intent who finished treatment. The median survival time was 8 months (range, 3-55 months) in the 10 patients with head and neck cancer who completed treatment with curative intent. Complete response was achieved in all of the patients with skin cancer without any major sequelae. Complete response was also observed in all three of the patients with non-Hodgkin lymphoma, but two patients treated with adjuvant chemotherapy died of drug-induced pneumonitis. Palliation was achieved in all nine of the patients treated with palliative intent.
Age of 90 years or older is not a limiting factor for radiation therapy.
Radiology 07/1999; 211(3):829-33. · 5.73 Impact Factor
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ABSTRACT: We reported that two established rat yolk sac tumor cell lines differ in their radiosensitivity by 1.7 fold, and the variation is most likely manifested by the differences seen in their apoptotic response. We investigated the relationship between radiosensitivity and p53 in these cell lines.
We assessed the status of p53 in cell lines by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequence analysis, and also analyzed protein expression of p53, p21, and bax as a function of time after irradiation to determine the signal transduction for p53 by immunoblotting.
A band shift was observed only in exon 7 for the radioresistant NMT-1R cells and no band shift was detected for the radiosensitive NMT-1 cells. A band shift was confirmed also at the mRNA level. Exon 7 of p53 DNA showed a three base substitution of DNA at codon 267 to 268. Expression of p53, p21, and bax proteins in NMT-1R cells did not change after 10 Gy irradiation; however, in NMT-1 cells, the expression of these proteins was increased from 1-12 h after irradiation.
A loss of p53 function by radiation-induced mutation of p53 decreased the radiosensitivity in these cell lines.
International Journal of Radiation OncologyBiologyPhysics 07/1999; 44(3):677-82. · 4.11 Impact Factor
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ABSTRACT: To determine the efficacy of stereotactic radiotherapy (SRT) in the treatment of recurrent nasopharyngeal carcinoma.
A retrospective review of the outcome of SRT for patients with recurrent nasopharyngeal carcinomas following definitive conventional radiation therapy.
Five patients were treated with daily static multiportal irradiation. Two Gy was administered with eight isocentric portals in a single plane 5 days a week, and the plane was changed for every 20 to 30 Gy. Of these patients, three had poorly differentiated squamous cell carcinoma. Tumor sizes ranged from 1 to 15 cm3, with a median size 3.2 cm3. Median follow-up time from SRT was 34 months (range, 4-61 mo).
Four of five recurrent tumors responded well and achieved complete regression. Three patients have survived without evidence of local recurrence with a median follow-up time of 34 months. Marginal recurrence was observed at the posterosuperior wall in a patient with adenoid cystic carcinoma at 30 months after SRT. One patient who received SRT after the two complete courses of radiation therapy died 6 months after SRT as a result of rupture of a branch of the left carotid artery, but autopsy revealed no local residual tumor.
Stereotactic radiotherapy with isocentric multiportals in one plane, which is changed at every 20 to 30 Gy, can provide local control with acceptable toxicity in patients with recurrent nasopharyngeal carcinoma, but increased clinical experience and longer follow-up will be necessary to evaluate the overall role of this technique in nasopharyngeal carcinoma.
The Laryngoscope 06/1999; 109(5):805-9. · 1.75 Impact Factor
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ABSTRACT: A case of malignant neuroendocrine tumor presenting a huge mediastinal mass controlled with radiation therapy is reported. A thoracotomy was performed on a 57-year-old male and a mass was found to invade the trachea, main bronchus, and left atrium. The tumor was unresectable. Subsequently, cisplatin was administered, but the tumor grew in size and radiation therapy was recommended. The tumor responded well to thoracic irradiation (56 Gy) and disappeared. Three months later, lymph nodes metastases were noted in the retrocrural and upper abdominal paraaortic regions, but these were controlled again with palliative irradiation. Without further treatment, he survived free of disease for over 5 years. Specimens obtained during the thoracotomy showed that the tumor consisted mainly of small round cells with a rosette formation. Immunohistochemically the tumor was positive to NSE and slightly positive to keratin, but negative to LCA, L26, UCLH-1, EMA, Leu7, and chromogranin, suggesting a malignant tumor derived from neuroendocrine tissue.
Lung Cancer 11/1998; 22(1):55-8. · 3.43 Impact Factor
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ABSTRACT: Phosphorus-31 magnetic resonance spectra (31P-MRS) were obtained from highly apoptotic murine lymphoma xenografts before and up to 24 hr following graded doses of radiation ranging from 2 to 30 Gy. Radiation-induced apoptosis was also estimated up to 24 hr by scoring apoptotic cells in tumor tissue.
Highly apoptotic murine lymphoma cells, EL4, were subcutaneously transplanted into C57/BL mice. At 7 days after transplantation, radiation was given to the tumor with a single dose at 3, 10, and 30 Gy. The beta-ATP/Pi, PME/Pi, and beta-ATP/PME values were calculated from the peak area of each spectrum. Radiation-induced apoptosis was scored with counting apoptotic cells on hematoxylin and eosin stained specimens (% apoptosis).
The values of % apoptosis 4, 8, and 24 hr after radiation were 21.8, 19.6, and 4.6% at 3 Gy, 35.1, 25.6, and 14.8% at 10 Gy, 38.4, 38.0, and 30.6% at 30 Gy, respectively (cf. 4.4% in control). There was no correlation between early change in beta-ATP/Pi and % apoptosis at 4 hr after radiation when most of the apoptosis occurred. An early decrease in PME/Pi was observed at 4 hr after radiation dose at 30 Gy. For each dose, the values of beta-ATP/Pi 24 hr after radiation were inversely related to radiation dose.
The increase in beta-ATP/Pi observed by 31P-MRS was linked to the degree of histological recovery from radiation-induced apoptosis.
International Journal of Radiation OncologyBiologyPhysics 08/1998; 41(5):1157-62. · 4.11 Impact Factor
