The use of the multislice CT for the determination of respiratory lung tumor movement in stereotactic single-dose irradiation.

Background: In three-dimensional (3-D) precision high-dose radiation therapy of lung tumors, the exact definition of the planning target volume (PTV) is indispensable. Therefore, the feasibility of a 3-D determination of respiratory lung tumor movements by the use of a multislice CT scanner was investigated.

Patients And Methods: The respiratory motion of 21 lung tumors in 20 consecutively treated patients was examined.

Assessment of focal liver reaction by multiphasic CT after stereotactic single-dose radiotherapy of liver tumors.

Purpose: To characterize and quantitatively assess focal radiation reactions in the liver after stereotactic single-dose radiotherapy for liver malignancies.

Methods And Materials: A total of 131 multiphasic CT scans were performed in 36 patients before and after stereotactic radiotherapy for liver tumors. The examination protocol included a nonenhanced scan and contrast-enhanced scans at different times after contrast injection.

Linac-based radiosurgery of cerebral melanoma metastases. Analysis of 122 metastases treated in 64 patients.

Purpose: Stereotactic radiosurgery is an alternative option to neurosurgical excision in the management of patients with brain metastases. We retrospectively analyzed patients with brain metastases of malignant melanoma who were treated at our institution for outcome and prognostic factors.

Patients And Methods: 64 patients with 122 cerebral metastases were treated with stereotactic radiosurgery between 1986 and 2000.

Stereotactic single-dose radiotherapy of stage I non-small-cell lung cancer (NSCLC).

Purpose: The treatment of early-stage lung cancers is a primary domain of thoracic surgery, leading to persuasive results. In patients with medical contraindications, radiotherapy is an alternative, although with considerably worse outcome. Radiotherapy is associated with the risk of severe acute side effects and a permanent decrease of lung function.

Fractionated stereotactic radiotherapy for craniopharyngiomas.

Purpose: To investigate outcome and toxicity after fractionated stereotactic radiation therapy (FSRT) in patients with craniopharyngiomas.

Methods And Materials: Twenty-six patients with craniopharyngiomas were treated with FSRT between May 1989 and February 2001. Median age was 33.

Detection of tumour progression in the follow-up of irradiated low-grade astrocytomas: comparison of 3-[123I]iodo-alpha-methyl- L-tyrosine and 99mTc-MIBI SPET.

Conventional MRI often fails to distinguish between progressive tumour and radiation injury, because both appear as mass lesions with unspecific Gd-DTPA enhancement. Furthermore, the sensitivity of FDG PET for the evaluation of malignant lesions in the brain is limited owing to high cortical uptake. The aim of this study was to assess the potential of alternative SPET tracers in the same group of patients.

Intensity-modulated radiotherapy of sacral chordoma--a case report and a comparison with stereotactic conformal radiotherapy.

In a case of partially resected sacral chordoma, the planning target volume (PTV) received 60 Gy and the gross target volume (GTV) 72 Gy using inversely planned, intensity-modulated, radiation therapy (IMRT). IMRT was compared with 3D-conformal radiotherapy (CRT). With IMRT, it was found that dose distribution is more homogeneous within the PTV outside the GTV and allows simultaneous dose escalation within the GTV.

Differentiation of radiation necrosis from tumor progression using proton magnetic resonance spectroscopy.

We report on a young woman who was treated by stereotactic radiotherapy for recurrence of an initially resected low-grade astrocytoma. MRI follow-up examination 7 months after radiotherapy showed a gadolinium-DTPA-enhancing mass lesion indicative of high-grade tumor progression. This assumption was also supported by positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose (FDG-PET).

Proton MR spectroscopic evaluation of suspicious brain lesions after stereotactic radiotherapy.

Background And Purpose: The radiologic assessment of suspicious brain lesions after stereotactic radiotherapy of brain tumors is difficult. The purpose of our study was to define parameters from single-voxel proton MR spectroscopy that provide a probability measure for differentiating neoplastic from radiation-induced, nonneoplastic lesions.

Methods: Seventy-two lesions in 56 patients were examined using a combined MR imaging and MR spectroscopy protocol (point-resolved spectroscopy, TE = 135 ms).

Postoperative radiotherapy of astrocytomas.

Astrocytomas account for the majority of primary brain tumors. Low-grade tumors are slowly growing tumors with relatively long overall survival. However, a high percentage of these tumors transform to more malignant, high-grade tumors.

[Stereotactic irradiation of liver metastases].

Purpose: A number of minimal-invasive methods have been developed for the treatment of non-resectable liver metastases. A focused high dose can be delivered to a liver tumor with sparing of surrounding normal liver tissue using non-invasive stereotactic techniques.

Methods: Sixty-six metastases were treated stereotactically in 43 patients during a phase 2 trial.

Stereotactic single-dose radiation therapy of liver tumors: results of a phase I/II trial.

Purpose: To investigate the feasibility and the clinical response of a stereotactic single-dose radiation treatment for liver tumors.

Patients And Methods: Between April 1997 and September 1999, a stereotactic single-dose radiation treatment of 60 liver tumors (four primary tumors, 56 metastases) in 37 patients was performed. Patients were positioned in an individually shaped vacuum pillow.

[First experiences with a noninvasive patient set-up system for radiotherapy of the prostate].

Purpose: Highly conformal radiotherapy techniques require precise patient positioning. We report our first experience with a new cast system for fixation of the pelvis during stereotactically guided intensity modulated radiotherapy (IMRT) of the prostate with respect to positioning accuracy of the prostate.

Material And Methods: The immobilization device consists of a custom-made wrap-around body cast that extends from the abdomen to the thighs and a separate head mask, both made from Scotchcast, and attaches to a frame for extracranial stereotaxy.

Extracranial stereotactic radiation therapy: set-up accuracy of patients treated for liver metastases.

Purpose: Patients with liver metastases might benefit from high-dose conformal radiation therapy. A high accuracy of repositioning and a reduction of target movement are necessary for such an approach. The set-up accuracy of patients with liver metastases treated with stereotactic single dose radiation was evaluated.

Noninvasive patient fixation for extracranial stereotactic radiotherapy.

Purpose: To evaluate the setup accuracy that can be achieved with a novel noninvasive patient fixation technique based on a body cast attached to a recently developed stereotactic body frame during fractionated extracranial stereotactic radiotherapy.

Methods And Materials: Thirty-one CT studies (> or = 20 slices, thickness: 3 mm) from 5 patients who were immobilized in a body cast attached to a stereotactic body frame for treatment of paramedullary tumors in the thoracic or lumbar spine were evaluated with respect to setup accuracy. The immobilization device consisted of a custom-made wrap-around body cast that extended from the neck to the thighs and a separate head mask, both made from Scotchcast.

A specific CpG methylation pattern of the MGMT promoter region associated with reduced MGMT expression in primary colorectal cancers.

The enzyme O6-methylguanine-DNA methyltransferase (MGMT) protects cells from the cytotoxic and mutagenic effects of alkylating agents. Approximately 20% of tumor cell lines lack MGMT activity and are highly sensitive to alkylating agents. In established cancer cell lines, MGMT expression appears to be correlated with methylation of residues in both the promoter and the body of the gene.

Confirmation that chromosome 18q allelic loss in colon cancer is a prognostic indicator.

Purpose: Recent studies suggest that allelic loss of sequences from the long arm of chromosome 18 may be a useful prognostic indicator in colorectal cancer. The aim of the present study was to confirm whether 18q loss of heterozygosity (LOH) is of prognostic value in patients with colon cancer.

Methods: Genomic DNA was prepared from archival tumor and corresponding normal tissue specimens from 151 patients who had undergone potentially curative surgery for adenocarcinoma of the colon.

Absence of TP53 alterations in pheochromocytomas and medullary thyroid carcinomas.

The role of the TP53 gene in the development of inherited and sporadic pheochromocytomas and medullary thyroid carcinomas (MTC) has not been clarified because of conflicting reports and limitations in the assays used to detect mutations. To determine the frequency of TP53 alterations in these tumors, 22 pheochromocytomas and 29 MTCs were screened for loss of heterozygosity (LOH) on 17p with four markers. Single-strand-conformation-variant (SSCV) analysis of exons 4-9 of the TP53 gene was performed in 20 of the pheochromocytomas and in 22 of the MTCs.

Parathyroid glands and the multiple endocrine neoplasia syndromes and familial hypocalciuric hypercalcemia.

Hypercalcemia is a variable feature of inherited endocrine disorders. In the multiple endocrine neoplasia (MEN) syndromes, generalized hyperparathyroidism is a common feature. It occurs much more frequently in patients with MEN type 1 as compared to patients with MEN type 2A.

Mutations in MLH1 are more frequent than in MSH2 in sporadic colorectal cancers with microsatellite instability.

The microsatellite instability that is a feature of tumors in patients with hereditary nonpolyposis colorectal cancer (HNPCC) is a consequence of defective DNA mismatch repair. Mutations in the DNA mismatch repair genes MSH2 and MLH1 may account for up to 90% of HNPCC kindreds. Microsatellite instability is also seen in 10-16% of sporadic colorectal cancers.

Surgical management of hyperparathyroidism in patients with multiple endocrine neoplasia type 2A.

Background: The surgical management of hyperparathyroidism in patients with multiple endocrine neoplasia type 2A (MEN 2A) is controversial. We report the long-term follow-up, mutational analysis, and surgical outcome in a large group of patients with MEN 2A and hyperparathyroidism.

Methods: Clinical and genetic data for MEN 2A patients with biochemically and pathologically confirmed hyperparathyroidism and a minimum of 5 years of follow-up were analyzed retrospectively, and outcomes after surgical management were compared.

Calcium regulating hormones after oral and intravenous calcium administration.

The aim of this study was to determine the changes in serum calcium concentration and in the concentrations of calcium regulating hormones after a single oral or intravenous calcium administration. Standard dosages of calcium, as used in routine patient care, were employed. Intact parathyrin, calcitonin, calcitriol, calcidiol, total calcium, ionized calcium, total protein and phosphate were determined in 12 healthy young men before and up to 8 h after oral and intravenous administration of calcium.

Circadian rhythm and pulsatility of parathyroid hormone secretion in man.

Objective: We wished to investigate the circadian rhythm and pulsatility of parathyroid hormone (PTH) secretion in man, as conflicting results have been published.

Design And Patients: To investigate the circadian rhythm during daytime, we sampled (a) peripheral blood at hourly intervals in 12 healthy young men from 0900 h until 1700 h. For observation of pulsatility, we sampled (b) peripheral blood at 1-minute intervals for 1 hour in three healthy men and three healthy women (mean 27.