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Yuta Shibamoto

Publications and source records attributed to Yuta Shibamoto.

At least 37 records · Page 2Linked to original sources
PubMed2004

Recovery from sublethal damage during intermittent exposures in cultured tumor cells: implications for dose modification in radiosurgery and IMRT.

PURPOSE: In stereotactic irradiation using a linear accelerator and intensity-modulated radiation therapy (IMRT), radiation is administered intermittently, and 30 min or longer is often required in one treatment session. The purpose of the present study was to determine how different the dose delivered with such intermissions is from that delivered continuously and to estimate dose-modifying factors. METHODS AND MATERIALS: Murine EMT6 and SCCVII cells in culture were used. First, two doses of 4 Gy were given with an interruption of 15 min to 6 h or 1-10 min, or without interruption. Next, five fractions of 1.6 Gy were given with interfraction intervals of 1 to 5 min each. Doses of 6.5-8 Gy were also given without interruption to estimate dose-modifying factors. Cell survival was determined by a colony assay. Furthermore, a total dose of 2 Gy was given in 5 or 10 even fractions at intervals of 1-5 min or 30 s-3 min each, respectively, and the results were compared with those obtained after 1.6-2 Gy delivered continuously by using a cytokinesis-block micronucleus assay. RESULTS: In the two-fraction experiments, a significant increase in cell survival resulting from recovery from sublethal damage (SLDR) was observed when the interruption time was 2 min or longer in EMT6 cells and 3 min or longer in SCCVII. With a 5-min interval, cell survival increased by 13% in EMT6 and by 18% in SCCVII. In the five-fraction experiments, SLDR was evident when the interfraction interval was 2 min or longer in both 8-Gy and 2-Gy dose experiments. In the 10-fraction experiment using a dose of 2 Gy, SLDR was evident when the interfraction interval was 1 min or longer. In the 5-fraction and 10-fraction experiments, the dose-modifying factors were between 1.08 and 1.16 when the total time for irradiation was between 20 and 30 min. CONCLUSIONS: The effects of stereotactic radiosurgery and IMRT that require considerably long beam interruption (e.g., 8 min or longer in total) may be less than those of the same dose administered continuously. In treatments that take 20 min or longer, dose modification appears necessary based on biologically estimated dose-modifying factors.

Animals↗
PubMed2004

Primary central nervous system lymphoma in Japan 1995-1999: changes from the preceding 10 years.

PURPOSE: Previously, we conducted a nationwide survey of primary central nervous system lymphoma (PCNSL) treated between 1985 and 1994 in Japan. In the present study, we conducted further investigations of PCNSL patients treated between 1995 and 1999 to clarify possible changes with time in the clinical features, treatment, and outcome of this disease. METHODS: Thirteen Japanese institutions were surveyed, and data on 101 patients with histologically-confirmed PCNSL were collected. These data were compared with those of 167 patients treated at the same institutions between 1985 and 1994. RESULTS: Regarding patient and tumor characteristics, the proportion of patients with good performance status (PS) was significantly higher in the group treated during 1995-1999 than in that treated during 1985-1994, but other characteristics were not significantly different. Regarding treatment, more patients in the more recent period (66%) received systemic chemotherapy than those in the preceding period (53%, P = 0.049). For all patients, including those who did not complete radiotherapy, the median survival time was 17 months and 30 months in patients treated between 1985 and 1994 and those treated between 1995 and 1999, respectively, and the 5-year survival rate was 15% versus 31% (P = 0.0003). In both patient groups, higher age and tumor multiplicity were associated with poor prognosis in multivariate analysis. In patients treated between 1995 and 1999, those who received systemic chemotherapy showed significantly better prognosis than those who did not (P = 0.0049), but the difference was not significant in multivariate analysis (P = 0.23). CONCLUSIONS: The high survival rates observed in the present survey are comparable with those of recent prospective studies employing intensive chemoradiotherapy. The improvement in prognosis appeared to result, at least in part, from the increase in the proportion of patients with better PS. Since the clinical feature and treatment outcome of patients with PCNSL can thus change with the era, historical control data should not be used in comparing different treatment modalities.

Adolescent↗
PubMed2004

In vitro and in vivo evaluation of novel antitumor prodrugs of 5-fluoro-2'-deoxyuridine activated by hypoxic irradiation.

PURPOSE: We previously developed a novel antitumor prodrug that has a 2-oxopropyl substituent at the N(1) position of 5-fluorouracil (5-FU) and releases 5-FU via one-electron reduction on hypoxic irradiation. Although the compound was effective in vivo, its activity against murine tumors was not high enough to warrant clinical studies. Therefore, we developed a similar family of radiation-activated prodrugs of 5-fluoro-2'-deoxyuridine (FdUrd), which is generally more potent than 5-FU, and investigated their radiation chemical reactivity and in vitro and in vivo effects. METHODS AND MATERIALS: Compounds bearing various 2-oxoalkyl substituents at the N(3) position of FdUrd were synthesized and investigated. After aerobic or hypoxic irradiation to the prodrugs dissolved in water or culture medium, release of FdUrd was measured using high-performance liquid chromatography. To investigate in vitro cytotoxicity, SCCVII and EMT6 cells in culture were irradiated in the presence of the prodrug under aerobic or hypoxic conditions, and then kept with the compound for 24 h. Cell survival was then measured using a colony assay. To investigate in vivo effects, the drug was injected intraperitoneally at a dose of 100 or 300 mg/kg into Balb/c mice bearing EMT6 tumors 30 min before irradiation. The tumor growth delay-time was then assessed. RESULTS: In vitro, the prodrugs released FdUrd at G-values (molar numbers of molecules produced by 1 J of radiation energy) of 1.6-2.0 x 10(-7) mol/J after hypoxic irradiation. The G-values for FdUrd release with hypoxic irradiation were about 100-fold greater than those with aerobic irradiation. Among the prodrugs tested, OFU106 bearing a 2-oxocyclopentyl substituent released the highest amount of FdUrd in the culture medium, and it was subjected to further in vitro and in vivo assays. Although OFU106 administered alone showed no cytotoxicity up to a concentration of 0.2 mM, it produced an enhanced cytotoxic effect when administered before hypoxic irradiation and kept with the cells for 24 h. The enhancement ratios calculated at the surviving fraction of 1% were 1.35-1.4 at 0.04 mM and 1.45-1.5 at 0.2 mM. In vivo, however, administration of OFU106 (100 or 300 mg/kg) before 20 Gy of irradiation did not produce marked growth delays compared with 20 Gy of radiation alone. CONCLUSION: On hypoxic irradiation in vitro, the prodrugs of FdUrd were activated as efficiently as were the prodrugs of 5-FU, but marked in vivo effects could not be detected. This strategy of prodrug design should be used in further development of radiation-activated prodrugs of more potent anticancer agents.

Animals↗
PubMed2004

A problem in diagnosing N3 disease using FDG-PET in patients with lung cancer--high false positive rate with visual assessment.

OBJECTIVE: To evaluate the accuracy of diagnosing N3 disease using positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) in patients with pulmonary disease. SUBJECTS AND METHODS: Twenty patients diagnosed as FDG-PET N3 were enrolled. On FDG-PET, lymph nodes were considered to be positive when increased uptake as compared with that of the surrounding mediastinum was visually observed, or the mean standardized uptake ratio (SUR) was more than 2, 2.5, or 3. On CT, lymph nodes exceeding 1 cm in the shortest diameter were regarded as positive. RESULTS: The PET result was true positive (TP) in 2 patients and false positive (FP) in 18 with an overall accuracy (OA) of 10% using visual criteria. Using an SUR of more than 2.5, the result was TP in 2, FP in 3, and true negative (TN) in 15, the false negative (FN) in 0, with an OA of 85%. CT diagnosis was TP in 2, FP in 9, and TN in 9 with an OA of 55%. The accuracy using the SUR criteria of more than 2.5 was superior to that of CT. CONCLUSION: Of 20 patients with the diagnosis of PET N3, we found frequent over-diagnosis in nodal staging using the visual criteria.

Aged↗
PubMed2004

False-positive and true-negative hilar and mediastinal lymph nodes on FDG-PET--radiological-pathological correlation.

OBJECTIVE: To compare histological findings of FDG-PET false-positive and true-negative hilar and mediastinal lymph nodes. METHODS: Sixty-seven lymphnode areas in 11 patients who were diagnosed to have N3 lymph nodes by FDG-PET and underwent surgery were histologically examined, and the histopathological findings in false-positive and true-negative lymph nodes were compared. Lymph nodes with higher accumulation of FDG than the surrounding mediastinum level were judged as positive. On histological sections, proportions of macrophages and lymphocytes, amount of coal dust deposit, presence of silicotic nodules, long- and short-axes of the largest node, and volume of macrophages and lymphocytes were evaluated. Correlations between the above-mentioned factors and FDG accumulation were evaluated. RESULTS: FDG uptake was not correlated with the proportion of macrophages and lymphocytes, coal dust amounts, or the presence of silicotic nodules. The long- and short-axes of the largest node in the false-positive areas were significantly longer than those in the true-negative areas (p = 0.01, and 0.001, respectively). Volumes of lymph nodes (mean +/- SD: 150 +/- 190 mm3) and macrophages (78 +/- 71 mm3) in false-positive areas were markedly larger than those in true-negative areas (68 +/- 87 mm3, p = 0.0009 and 34 +/- 54 mm3, p = 0.0001, respectively). The volume of lymphocytes was also larger in false-positive areas but less markedly. CONCLUSION: Our study suggested that false-positive results of FDG-PET in hilar and mediastinal lymph nodes were closely related to the size of lymph node and the volume of macrophages.

Aged↗
PubMed2004

MRI and CT findings of neurohypophyseal germinoma.

OBJECTIVE: Magnetic resonance (MR) imaging and computed tomography (CT) findings of neurohypophyseal germinoma have not previously been described in detail. The purpose of the present study was to establish the spectrum of MR imaging and CT findings in neurohypophyseal germinomas. MATERIALS AND METHODS: MR and CT images of 13 consecutive patients (seven males, six females; mean age: 15 years; range: 6-31 years) with neurohypophyseal germinoma were retrospectively analyzed. The diagnosis had been made either histologically (n=8) or clinically according to established criteria (n=5). All patients had been examined using MR imaging and CT before treatment. RESULTS: On MR imaging, infundibular thickening (up to 16 mm) was observed in all 13 cases. Hyperintensity of the posterior pituitary on T1-weighted image was absent in all 13 cases (100%) and 12 of the 13 displayed central diabetes insipidus. Ten germinomas (77%) were isointense to cerebral cortex on T1-weighted image, but variable intensities were exhibited on T2-weighted image. MR images revealed intratumoral cysts in six cases (46%), most of which demonstrated intra-third ventricular extension. Eleven of the 13 cases (85%) revealed hyperdense solid components on unenhanced CT. Calcification was absent in all cases (100%). CONCLUSION: Infundibular thickening, absence of the posterior pituitary high signal on T1-weighted image, lack of calcification and hyperdensity on unenhanced CT are common imaging features of neurohypophyseal germinoma.

Adolescent↗
PubMed2004

Biologic premises of combined radiation therapy and chemotherapy in lung cancer.

When radiation is combined with concurrent chemotherapy, independent cell kill and enhancement of tumor response may be expected. On the other hand, spatial cooperation may be the main rationale for sequential combination of the two modalities. Among many new agents being investigated, radiation-activated antitumor prodrugs have a therapeutic potential as a new method to effectively combine radiation and concurrent chemotherapy.

Combined Modality Therapy↗
PubMed2004

The Japanese experiences with hypoxia-targeting pharmacoradiotherapy: from hypoxic cell sensitisers to radiation-activated prodrugs.

Tumour hypoxia is a negative factor in cancer radiotherapy. In order to overcome the problem, various pharmacotherapies have been investigated as an adjunct to radiotherapy. The use of hypoxic cell sensitisers is a classical strategy, and many new compounds have been developed and investigated. Development of more efficient compounds than those currently available seems difficult and clinical studies to prove the efficacy of the existing compounds are encouraged, especially in combination with radiosurgery, intraoperative radiotherapy, and interstitial irradiation, in which a single high dose of radiation is used. Following the advent of hypoxic cell sensitisers, hypoxic cytotoxins have become available. Among them, tirapazamine has already gained success when combined with cisplatin in non-small cell lung cancer. The beneficial effect of tirapazamine when combined with radiation needs to be determined. As a third-generation compound in this field, antitumour prodrugs that are activated by irradiation under hypoxic conditions via one-electron reduction have been proposed. Prodrugs of 5-fluorouracil and 5-fluoro-2'-deoxyuridine have shown in vivo as well as in vitro activity. Although clinical evaluation of the compounds is not warranted due to a relatively low in vivo effect, this strategy appears promising if the prodrug design can be applied to more potent agents that shall be developed in future.

Asian People↗
PubMed2003

Is whole-brain irradiation necessary for primary central nervous system lymphoma? Patterns of recurrence after partial-brain irradiation.

BACKGROUND: Neurotoxicity after whole-brain irradiation remains a major problem in the treatment of primary central nervous system lymphoma (PCNSL). To clarify whether whole-brain radiation is necessary for PCNSL, the authors retrospectively analyzed the outcome of patients treated with partial-brain irradiation. METHODS: A nationwide survey was performed regarding the treatment of PCNSL. Among 62 institutions surveyed, 7 were identified in which whole-brain irradiation was not necessarily employed. Questionnaires were sent to these institutions and 43 patients who had been treated using partial-brain fields since 1985 were collected. Thirty-two patients had solitary lesions and 11 had multiple lesions. Patterns of recurrence could be identified in 38 patients. RESULTS: The cumulative in-field and out-field recurrence rates at 5 years were 57% and 49%, respectively. Of 14 out-field recurrences, 2 occurred at the safety margin of the previous radiation field. The out-field recurrence rate was 45% in patients with a single lesion and 67% in those with multiple tumors (P = 0.79). The out-field recurrence rate was 22% for patients treated with safety margins of > or = 4 cm and 83% for those treated with safety margins of < 4 cm (P = 0.0079). The median survival time and the 5-year survival rate were 28.5 months and 20%, respectively, in the former group of patients and 15 months and 11%, respectively, in the latter group (P = 0.057). CONCLUSIONS: Focal radiotherapy with safety margins of < 4 cm appears to be associated with a very high rate of out-field recurrence, but the use of a radiation field with generous safety margins (> or = 4 cm) appears to be worth further investigation.

Adolescent↗
PubMed2003

Stage I and II aggressive B-cell lymphomas of the head and neck: radiotherapy alone as a treatment option and the usefulness of the new prognostic index B-ALPS.

PURPOSE: To evaluate the outcome according to treatment modality and prognostic factors in clinical Stage I and II intermediate- or high-grade B-cell lymphomas of the head and neck. METHODS AND MATERIALS: We analyzed 155 patients treated between 1983 and 1997, excluding those with the Working Formulation low-grade lymphomas. Of these patients, 88 had Stage I and 67 had Stage II disease. Forty-one patients were treated with radiotherapy (RT) alone, and 114 patients were treated with a combination of RT and chemotherapy. Most of the chemotherapy regimens included anthracycline derivatives. More patients with Stage I disease and more patients with poor performance status were treated with RT alone. The treatment results were evaluated according to the new prognostic index B-ALPS, consisting of tumor bulk, age, lactate dehydrogenase level, performance status, and stage. RESULTS: The 5-year overall and failure-free survival rate was 71.5% and 68.3%, respectively, for all 155 patients. The 5-year survival rate was 67% for those treated with RT alone and 73% for those treated with radiochemotherapy (p = 0.13). Among the various potential prognostic factors, age >60 years, World Health Organization performance status 2-4, and tumor size >or=6 cm were associated with poorer survival. The 5-year survival rate was 82% for those with no or one B-ALPS factor, 66% for those with two factors, and 49% for those with three or more factors (p <0.0001). The B-ALPS index appeared to predict the prognosis of these patients better than did the International Prognostic Index. No single prognostic factor was useful to identify patient groups more suitable to treatment with RT alone, but in patients with two B-ALPS risk factors, those treated with radiochemotherapy had a better survival rate and tended to have a better failure-free survival rate than those treated with RT alone. CONCLUSION: A proportion of patients with clinical Stage I or II head-and-neck B-cell lymphoma may be successfully treated with RT alone. B-ALPS is a useful prognostic index in this disease.

Adult↗
PubMed2003

Impact of treatment interruptions due to toxicity on outcome of patients with early stage (I/II) non-small-cell lung cancer (NSCLC) treated with hyperfractionated radiation therapy alone.

We investigated the effect of treatment interruptions due to high-grade (> or =3) toxicity on outcome of patients with early stage (I/II) non-small-cell lung cancer treated with hyperfractionated radiation therapy (Hfx RT). Of 116 patients treated with total tumour doses of 69.6 Gy, 1.2 Gy b.i.d. fractionation, 44 patients refused surgery while 72 patients were medically inoperable due to existing co-morbid states. Patients who were medically inoperable had worse KPS (P=0.0059) and more pronounced weight loss (P=0.0005). Among them, 12 patients experienced high-grade toxicity and 11 of them with either acute (n=6) or "consequential" late (n=5) high-grade toxicity requested interruption in the Hfx RT course (range, 12-25 days; median, 17 days). Superior survival (OS) was observed in patients who refused surgery when compared to those who were medically inoperable (P=0.0041), as well as superior local recurrence-free survival (LRFS) (P=0.011), but not different distant metastasis-free survival (P=0.14). Cause-specific survival (CSS) also favoured patients who refused surgery (P=0.004). Multivariate analysis showed independent influence of the reason for not undergoing surgery on OS (P=0.035), but not on LRFS (P=0.084) or CSS (P=0.068). Patients who refused surgery did not experience high-grade toxicity (0/44), whereas 11 of 72 patients with medical inoperability and co-morbid states experienced high-grade toxicity and had treatment interruptions to manage toxicity (P=0.0064). Patients without treatment interruptions had significantly better OS (P=0.00000), LRFS (P=0.00000) and CSS (P=0.00000) than those with treatment interruptions. When corrected for treatment interruptions, the reason for not undergoing surgery independently influenced OS (P=0.040), but not LRFS (P=0.092) or CSS (P=0.068). In contrast to this, treatment interruption was independent prognosticator of all three endpoints used (P=0.00031, P=0.0075 and P=0.00033, respectively). When 11 patients with treatment interruptions were excluded, the reason for not undergoing surgery still affected OS (P=0.037) and CSS (P=0.039) but not LRFS (P=0.11). Multivariate analyses using OS, CSS and LRFS showed that the reason for not undergoing surgery affected OS (P=0.0436), but neither CSS (P=0.083) nor LRFS (P=0.080).

Adult↗
PubMed2003

Cardiac hemangioma of the left atrial appendage: CT and MR findings.

Cardiac hemangiomas are rare, benign primary cardiac neoplasms. We describe the CT and MR imaging findings of a cardiac hemangioma arising from the myocardium of the left atrial appendage and protruding into the pericardial cavity. The tumor displayed homogenous density on CT, heterogeneous signal intensity on MR, and inhomogeneous enhancement after intravenous contrast administration. The hemangioma in this case was difficult to differentiate from other myocardial or a pericardial tumor.

Aged↗
PubMed2003

[Evidence-based radiation therapy for primary brain tumors].

Radiation therapy for five primary brain tumors is discussed based on the results of prospective trials. Many randomized studies have revealed the usefulness of radiation and radiochemotherapy for treating malignant gliomas, and the ineffectiveness of many new treatments modalities. However, novel treatments should be tested further against this tumor. In low-grade gliomas, the usefulness of radiotherapy was shown but a dose-effect relationship was not observed in recent randomized studies. In medulloblastoma, the difficulty in reducing the dose to the cerebrospinal axis has been shown even in low-stage patients. On the other hand, reliable randomized studies are still lacking for germinoma and primary central nervous system lymphoma, and the usefulness of combination chemotherapy remains uncertain. In the future, more prospective studies are needed for primary brain tumors other than glioma. Establishment of IMRT and controlled studies to prove its efficacy are important in the field of neuro-oncology.

Antineoplastic Agents, Alkylating↗
PubMed2002

Clinical outcomes of 3D conformal hypofractionated single high-dose radiotherapy for one or two lung tumors using a stereotactic body frame.

PURPOSE: This study was performed to evaluate the clinical outcomes of three-dimensional (3D) conformal hypofractionated single high-dose radiotherapy for one or two lung tumors using a stereotactic body frame. MATERIALS AND METHODS: Forty patients who were treated between July 1998 and November 2000 and were followed for >10 months were included in this study. Of the 40 patients, 31 had primary lung cancer and 9 had metastatic lung cancer. The primary lung cancer was staged as T1N0M0, T2N0M0, and T3N0M0 in 19, 8, and 4 patients, respectively. The primary sites of metastatic lung cancer were the colon in 4, tongue in 2, and osteosarcoma, lung cancer, and hepatocellular carcinoma in 1 each. 3D treatment planning was performed to maintain the target dose homogeneity within 15% and to decrease the irradiated lung volume from >20 Gy to <25%. All patients were irradiated using a stereotactic body frame and received 4 times 10-12 Gy single high-dose radiation at the isocenter during a period of 5-13 days (median 12). RESULTS: The initial 3 patients received 40, and the remaining 37 patients received 48 Gy after dose escalation. Of the 33 tumors followed >6 months, 6 tumors (18%) disappeared completely after treatment. Twenty-five tumors (76%) decreased in size by 30% or more after treatment. Therefore, 31 tumors (94%) showed a local response. During the follow-up of 4-37 months (median 19), no pulmonary complications greater than National Cancer Institute-Common Toxicity Criteria Grade 2 were noted. Of the 16 patients with histologically confirmed T1N0M0 primary lung cancer who received 48 Gy, all tumors were locally controlled during the follow-up of 6-36 months (median = 19). In 9 tumors with lung metastases that were irradiated with 48 Gy in total, 2 tumors did not show a local response. Finally, 3 tumors (33%) with lung metastases relapsed locally at 6-12 months (median 7) after treatment during the follow-up of 3-29 months (median 18). CONCLUSION: 3D conformal hypofractionated single high-dose radiotherapy of 48 Gy in 4 fractions using a stereotactic body frame was useful for the treatment of lung tumors.

Adolescent↗
PubMed2002

No thoracic radiation myelitis after spinal cord dose > or = 50.4 Gy using 1.2. Gy b.i.d. fractionation in patients with Stage III non-small cell lung cancer treated with hyperfractionated radiation therapy with and without concurrent chemotherapy.

We investigated a risk of developing radiation myelitis during four prospective studies using hyperfractionated radiation therapy (HFX RT) with and without concurrent chemotherapy (CHT) during which a portion of thoracic spinal cord received a dose > or = 50.4 Gy given via 1.2 Gy b.i.d. fractionation. Of 536 patients with Stage III non-small cell lung cancer (NSCLC) which were treated on three prospective randomised Phase III studies and one Phase II study, 336 patients received irradiation dose > or = 50.4 Gy to a portion of their spinal cord and survived >1 year after the beginning of therapy. None of these 336 patients developed thoracic radiation myelitis. Therefore, the influence of potentially contributing factors on the occurrence of radiation myelitis, such as cord length, interfraction interval, or administration of concurrent CHT was not possible to investigate. These results give new insight about the influence of total dose/dose per fraction/interfraction interval with or without concurrent CHT on the thoracic spinal cord toxicity.

Adult↗
PubMed2002

Second single 4 Gy reirradiation for painful bone metastasis.

To investigate the efficacy of the second 4 Gy given as a single fraction radiotherapy (RT) for patients with painful bone metastasis who had already twice received single fraction RT (4, 6, or 8 Gy plus 4 Gy), a total of 25 patients were assessed before and after re-irradiation. The patients included 19 responders and 6 nonresponders to two prior single fraction RT, the latter one being 4 Gy. The overall response rate was 80%, with both complete response (CR) and partial response (PR) being 40%. No difference was found between the previous responders and previous nonresponders regarding both CR (P = 0.70) and overall response rate (P = 0.35). Response duration was longer in the previous responders (P = 0.0041), but the time to pain relief was similar between the two treatment groups. No acute or late high-grade toxicity was observed during this study and no pathological fractures or spinal cord compressions were seen. In this small and highly selected series of patients, the third single fraction RT of 4 Gy was effective and not toxic in the treatment of painful bone metastasis.

Adult↗
PubMed2002

Postoperative radiotherapy for intracranial ependymoma: analysis of prognostic factors and patterns of failure.

The long-term results of external beam radiotherapy following surgical resection in patients with intracranial ependymomas were evaluated to identify the prognostic factors and the pattern of recurrence. Between June 1961 and January 1999, 48 patients with intracranial ependymoma were treated with external beam irradiation with >40 Gy following surgery. Total doses of 40.5-63.4Gy were delivered to the tumor site in 22-46 fractions over 33-101 days. Six patients with spinal deposit or positive cerebrospinal fluid cytology received whole spinal axis irradiation, and 4 patients received prophylactic spinal irradiation. The median follow-up of surviving patients was 110 months. The 10-year overall and relapse-free survival rates were 47% and 42%, respectively. In multivariate analysis, female gender, lower tumor grade and total resection were found to be associated with better relapse-free survival. Twenty of 26 recurrences developed at the primary tumor site (inside the irradiation field), two at the unirradiated cerebellum and spinal cord, and four at the spinal cord without intracranial failure. Only one of 34 patients with supratentorial tumors developed isolated spinal metastasis, whereas 3 of 14 patients with infratentorial tumors did so. Regarding the late neurotoxicity of radiotherapy, one of the 15 long-term (>4 years) survivors whose psychosocial status could be evaluated showed marked cognitive impairment. It was suggested that the use of new treatment strategies to improve local control would be warranted, and that prophylactic whole spinal axis irradiation appeared to be of more benefit in patients with infratentorial tumors than in those with supratentorial tumors.

Adolescent↗