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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a strict method for measuring tumor size, we evaluated tumor response to radiosurgery in 88 patients with 89 acoustic tumors treated over 3 years with a 201-source cobalt-60 gamma unit. Overall, tumor size was unchanged in 73% of patients and increased in 4%. In 22% of patients, tumor diameter decreased an average of 4.9 mm 3-33 months after treatment. Tumor shrinkage occurred in 36% of 50 patients who were followed for at least 1 year after treatment. Loss of tumor contrast enhancement was seen in 79% of patients 1-18 months after treatment. Delayed communicating hydrocephalus developed in four patients. In eight patients, increased signal on T2-weighted MR images developed in the adjacent cerebellar peduncle (n = 5) or the peduncle and dorsolateral pons (n = 3) 5-15 months after treatment. T1-weighted MR imaging and CT were insensitive to these adjacent brain changes. Stereotaxic radiosurgery is an important alternative treatment for selected patients with acoustic tumors. There is no mortality or major perioperative morbidity, hospitalization time and costs are smaller than for microsurgery, patient employment or functional level is maintained, and hearing preservation and facial neuropathy rates are comparable to those in published microsurgical series. Although the rate of occurrence of trigeminal neuropathy is greater than those reported in published microsurgical series, the majority of cases are mild, transient, and nondebilitating. MR imaging before and after radiosurgery is the most sensitive imaging tool to evaluate tumor response, the presence of adjacent parenchymal signal changes, and ventricular size. With a mean follow-up time of 14.6 months, the rate of complications detected by neuroimaging is low and the tumor control rate is 96%.
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PMID:Neuroimaging of acoustic nerve sheath tumors after stereotaxic radiosurgery. 176 44

Fifty-seven uveal malignant melanomas (T2: 36.8%; T3: 49.1%) were treated between 1983 and 1989 with Cobalt 60 or/and Ruthenium 106 Rhodium 106 plaques. The mean follow-up was 32 months (from 6 to 69 months). A diminution of tumor size was observed in 88% of the cases, either rapid and marked (57%), or slower and more moderate (31%). A multivariate study showed the radiation dose administered to the tumor edge to be the most significant parameter associated with the tumor control. Seven patients developed metastases, and the probability of survival at 60 months was 83.3%. This probability was identical to that of 59 comparable patients treated, some years before, by enucleation. The most frequent complications were radiation retinopathy (28.1%) and retinal detachment (15.8%). The treated eye was retained in 86% of cases. In 57% of treated eyes, vision remained better or equal to 0.1. The predictive parameters of vision impairment after treatment seemed to be tumor size, tumor site near the macula and the optic nerve, and the radiation dose to the tumor base. The use of Ruthenium 106 Rhodium 106 appeared to be advantageous in controlling the disease as well as in reducing the incidence of complications.
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PMID:[Oncologic and functional results of 57 malignant melanoma of the uvea treated by curietherapy]. 177 10

Twelve dogs with appendicular osteosarcoma were treated with 24-40 Gy of cobalt 60 radiation and two doses of intraarterial cisplatin. Improvement in limb function occurred in four dogs, and three dogs, which had only mild initial lameness, had no worsening of their lameness post-treatment. In nine dogs in which local control was evaluable, eight had local failure, with the median (95% CI) duration of local control being 5.9 (4.6, 6.7) months. Two dogs had metastatic disease before therapy, and an additional nine dogs had metastatic disease at a median time of 6.4 months. Pathologic fracture was present in four dogs; two fractures occurred before treatment and two were documented at the time of tumor recurrence. Median (95% CI) survival time for all 12 dogs was 4.9 (3.4, 6.8) months. Excluding the two dogs with preexisting metastatic disease, median survival time was 6.7 months. Three dogs survived longer than 1 year. This mode of therapy was well tolerated and may be considered an alternative to amputation or limb-sparing surgical procedures in selected dogs with appendicular osteosarcoma.
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PMID:Treatment of canine appendicular osteosarcoma using cobalt 60 radiation and intraarterial cisplatin. 177 23

Intracranial venous sinus thrombosis is an uncommon cause of pseudotumor cerebri. The diagnosis is often not confirmed on the rationale that treatment will not be altered. We report a case presenting a pseudotumor cerebri where the underlying pathology disclosed dural sinus thrombosis resulting from compression by an eosinophilic granuloma of the occipital bone. Routine CT of the head and Technetium-99m brain scan initially demonstrated neither tumor nor thrombosis. Plain skull x-rays subsequently revealed a lytic lesion of the occiput. When reinvestigated with CT using bone density windows the tumor was revealed. Excision of the tumor and a short course of cobalt therapy was curative. Special techniques in nuclear scanning, CT and MRI designed to improve the sensitivity for diagnosing venous sinus thrombosis are described. This case illustrates the importance of establishing a definitive diagnosis and shows the importance of pre-test consultation between clinicians and radiologists to ensure that specific investigative techniques are properly utilized.
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PMID:Eosinophilic granuloma of the occipital bone presenting as intracranial venous hypertension. 178 21

Fifty patients with meningiomas were treated during the initial 30 months experience using the 201 source cobalt-60 gamma knife at the University of Pittsburgh. The most frequent site of origin was the skull base. Stereotactic radiosurgery was the primary treatment modality in 16 (32%) patients with symptomatic tumors demonstrated by neuroimaging. Thirty-six patients (72%) had undergone at least one craniotomy, and 4 patients (8%) previously had fractionated external beam radiation therapy. The proximity of cranial nerves, vascular, pituitary and brainstem structures to the often convoluted tumor mass was crucial to dose selection. Follow-up imaging studies and clinical analysis of patients were performed at 6-month intervals. The actuarial 2-year tumor control rate was 96%. Only 2 patients have shown delayed tumor growth outside the radiosurgical treatment volume. To date, stereotactic radiosurgery proved to be a relatively safe and effective therapy for selected patients with symptomatic meningiomas, either as an adjuvant treatment to prior resection, or as a primary treatment alternative for patients whose advanced age, medical condition or high-risk tumor location mitigated against surgical resection.
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PMID:Gamma knife radiosurgery of meningiomas. 180 51

The results of treatments applied to 142 patients with breast carcinoma stage III, in the Oncology Service from 1965 to 1974 are as follows: successive cycles of treatments were applied: irradiation with X-rays of 280 Kv-20 mA for ulcerated tumors or Cobalt 60 for non-ulcerated tumors, using a dose of 5,500 rad in eight weeks. Subsequently, in cases of residual neoplasia, mastectomy was used or an extra dose of 1,500 to 3,000 rad. Later, at the first sign of the spread of carcinoma, hormonal therapy was given and then chemotherapy. Survival rate after five years was as follows: 41.54% of patients survived and 58.45% died from the cancer.
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PMID:[Breast cancer in clinical stage III. Multidisciplinary treatment]. 181 40

To evaluate the lifetime hazards of ionizing radiation exposure, 1680 beagles received whole-body, 60-Cobalt gamma exposures or sham-exposures during development. Eight groups of 120 dogs each received mean doses of 16 or 83 cGy at 8 (preimplantation), 28 (embryonic), or 55 (late fetal) days postcoitus (dpc), or 2 (neonatal) days postpartum (dpp). One group of 120 dogs received 83 cGy at 70 dpp (juvenile), and one group of 240 dogs received 83 cGy at 365 dpp (young adult). Sham-irradiations were delivered to 360 controls. Sexes were equally represented. Young dogs, up to 4 years of age, had an increase in benign and malignant neoplasms after irradiation in the perinatal period at 55 dpc or 2 dpp. Among these, 4 fatal cancers were observed. No malignancies occurred in comparably-aged controls. The increase in both fatal neoplasms and all neoplasms in the perinatally-exposed groups were statistically significant. Over the full lifetime, dogs irradiated in the perinatal period also had the strongest evidence for an increased risk for fatal malignancies of all types. Though not as strong, there was a trend for increased risk for fatal cancer in dogs irradiated at all other ages. The risk of fatal malignancy after irradiation was greater in females than in males. Dogs exposed at 55 dpc had a significant increase in lymphoid neoplasia and dogs exposed at 8 and 55 dpc had increased risk for hemangiosarcoma. There was no evidence for an increased risk for mammary carcinoma in irradiated females. Dogs exposed as juveniles at 70 dpp had a significant increase in all benign and malignant thyroid neoplasms, including fatal thyroid carcinoma.
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PMID:Radiation carcinogenesis in dogs irradiated during prenatal and postnatal development. 182 70

Although 5-fluoro-2'-deoxyuridine (FdUrd) has been combined with hyperfractionated radiation therapy in clinical trials, the optimal method of delivering radiation therapy is not yet known. To determine the importance of the time interval between fractions on the survival of tumor cells exposed to FdUrd, we studied the effect of FdUrd on sublethal damage repair in HT29 human colon cancer cells in culture. Cells were exposed to clinically achievable concentrations of FdUrd (10-100 nM) for 14 hr followed by either single dose (8-12 Gy) or split dose (4-6 Gy x 2) external cobalt irradiation. The interval between radiation fractions was varied from 0.5 to 6 hr. FdUrd impaired sublethal damage repair in a dose dependent fashion. FdUrd had no effect on the induction of DNA double strand breaks (DSB's), but significantly reduced the rate of the repair of DNA DSB's. Exposure to 100 nM FdUrd decreased intracellular TTP pools but elevated dATP pools. These findings suggest that FdUrd may decrease sublethal damage repair by perturbing nucleotide triphosphate pools, which leads to a decrease in the ability of the cell to repair DNA DSB's. Furthermore, they suggest that hyperfractionated irradiation will be superior to once daily treatment when combined with regional delivery of FdUrd.
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PMID:The effect of fluorodeoxyuridine on sublethal damage repair in human colon cancer cells. 183 63

The authors investigated the impact of local intraocular tumor relapse on survival in a matched-group comparison study of patients with primary choroidal or ciliary body melanoma managed with cobalt 60 plaque radiotherapy. Sixty-two patients with local relapse were matched with an equal number of relapse-free patients in terms of known clinical prognostic factors for both melanoma-specific mortality (largest linear tumor dimension, location of anterior tumor margin, age) and local tumor relapse (location of posterior tumor margin). The follow-up of every relapse-free patient equaled or exceeded the interval to relapse for each matched patient with local relapse. The estimated 5-year survival (Kaplan-Meier) in the relapse-free patients was 87% (standard error = 4%), while that in the local relapse group was 58% (standard error = 6%). This difference is statistically significant (P less than 0.0001, log rank test). These results support the hypothesis that local tumor relapse after cobalt 60 plaque radiotherapy is an important post-treatment clinical indicator of the tumor's greater malignant potential and the patient's increased risk of melanoma-specific mortality.
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PMID:Impact of local tumor relapse on patient survival after cobalt 60 plaque radiotherapy. 186 54

Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 x 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, we are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications.
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PMID:Cobalt60 plaques in recurrent retinoblastoma. 186 58


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