[What is the impact of new radiotherapy techniques?]. / Was leisten die neuen Bestrahlungstechniken?

Radiation oncology, along with surgery and chemotherapy, is one of the cornerstones in the treatment of head and neck tumors. Within the last years, this field has experienced a remarkable evolution of new technical possibilities. New imaging modalities have been introduced into radiation planning and into linear accelerators themselves. In addition, new techniques enable the tailor-made conformation of radiation beams and dose distributions to complex tumor geometries. At the same time, organs at risk can be spared, and long-term toxicities are considerably reduced. This report presents the new techniques in radiation oncology and describes the effects on new treatment options and patients' quality of life.

Treatment of non-small cell lung cancer with intensity-modulated radiation therapy in combination with cetuximab: the NEAR protocol (NCT00115518).

BACKGROUND: Even today, treatment of Stage III NSCLC still poses a serious challenge. So far, surgical resection is the treatment of choice. Patients whose tumour is not resectable or who are unfit to undergo surgery are usually referred to a combined radio-chemotherapy. However, combined radio-chemotherapeutic treatment is also associated with sometimes marked side effects but has been shown to be more efficient than radiation therapy alone. Nevertheless, there is a significant subset of patients whose overall condition does not permit administration of chemotherapy in a combined-modality treatment. It could be demonstrated though, that NSCLCs often exhibit over-expression of EGF-receptors hence providing an excellent target for the monoclonal EGFR-antagonist cetuximab (Erbitux) which has already been shown to be effective in colorectal as well as head-and-neck tumours with comparatively mild side-effects. METHODS/DESIGN: The NEAR trial is a prospective phase II feasibility study combining a monoclonal EGF-receptor antibody with loco-regional irradiation in patients with stage III NSCLC. This trial aims at testing the combination's efficacy and rate of development of distant metastases with an accrual of 30 patients. Patients receive weekly infusions of cetuximab (Erbitux) plus loco-regional radiation therapy as intensity-modulated radiation therapy. After conclusion of radiation treatment patients continue to receive weekly cetuximab for 13 more cycles. DISCUSSION: The primary objective of the NEAR trial is to evaluate toxicities and feasibility of the combined treatment with cetuximab (Erbitux) and IMRT loco-regional irradiation. Secondary objectives are remission rates, 3-year-survival and local/systemic progression-free survival.

[Advances in radio-oncology. From precision radiotherapy with photons to ion therapy with protons and carbon ions]. / Fortschritte in der Radioonkologie. Von der Präzisionsstrahlentherapie mit Photonen zur Ionentherapie mit Protonen und Kohlenstoffionen.

Modern techniques in radiation oncology, such as fractionated stereotactic radiotherapy (FSRT), stereotactic radiosurgery (SRS) or intensity modulated radiotherapy (IMRT) allow the application of high local doses to defined treatment volumes, while normal structures in close vicinity can be spared; high local control rates can be achieved, while treatment-related toxicity can be minimized. Innovative Hi-Art tomotherapy systems offer an alternative, combining a 6 MV photon accelerator with a CT scanner. Ion beams, such as protons and carbon ions, have been shown to be beneficial for distinct tumor entities. Both offer a characteristic physical dose distribution with an inverse dose profile contributing to beneficial dose conformality. Carbon ions also offer the advantage of increased relative biological effectiveness. For certain tumor types, a significant increase in local control and survival rates could be obtained with carbon ions.

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. The applied dose was escalated from 14 to 26 Gy (reference point), with the 80% isodose surrounding the planning target volume. Median tumor size was 10 cm(3) (range, 1 to 132 cm(3)). The morbidity, clinical outcome, laboratory findings, and response as seen on computed tomography (CT) scan were evaluated. RESULTS: Follow-up data could be obtained from 55 treated tumors (35 patients). The median follow-up period was 5.7 months (range, 1.0 to 26.1 months; mean, 9.5 months). The treatment was well tolerated by all patients. There were no major side effects. Fifty-four (98%) of 55 tumors were locally controlled after 6 weeks at the initial follow-up based on the CT findings (22 cases of stable disease, 28 partial responses, and four complete responses). After a dose-escalating and learning phase, the actuarial local tumor control rate was 81% at 18 months after therapy. A total of 12 local failures were observed during follow-up. So far, the longest local tumor control is 26.1 months. CONCLUSION: Stereotactic single-dose radiation therapy is a feasible method for the treatment of singular inoperable liver metastases with the potential of a high local tumor control rate and low morbidity.

Randomized phase II--study evaluating EGFR targeting therapy with cetuximab in combination with radiotherapy and chemotherapy for patients with locally advanced pancreatic cancer--PARC: study protocol [ISRCTN56652283].

BACKGROUND: Pancreatic cancer is the fourth commonest cause of death from cancer in men and women. Advantages in surgical techniques, radiation therapy techniques, chemotherapeutic regimes, and different combined-modality approaches have yielded only a modest impact on the prognosis of patients with pancreatic cancer. Thus there is clearly a need for additional strategies. One approach involves using the identification of a number of molecular targets that may be responsible for the resistance of cancer cells to radiation or to other cytotoxic agents. As such, these molecular determinants may serve as targets for augmentation of the radiotherapy or chemotherapy response. Of these, the epidermal growth factor receptor (EGFR) has been a molecular target of considerable interest and investigation, and there has been a tremendous surge of interest in pursuing targeted therapy of cancers via inhibition of the EGFR. METHODS/DESIGN: The PARC study is designed as an open, controlled, prospective, randomized phase II trial. Patients in study arm A will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine infusions weekly over 4 weeks. Patients in study arm B will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine weekly over 4 weeks and cetuximab infusions over 12 weeks. A total of 66 patients with locally advanced adenocarcinoma of the pancreas will be enrolled. An interim analysis for patient safety reasons will be done one year after start of recruitment. Evaluation of the primary endpoint will be performed two years after the last patient's enrollment. DISCUSSION: The primary objective of this study is to evaluate the feasibility and the toxicity profile of trimodal therapy in pancreatic adenocarcinoma with chemoradiation therapy with gemcitabine and intensity modulated radiation therapy (IMRT) and EGFR-targeted therapy using cetuximab and to compare between two different methods of cetuximab treatment schedules (concomitant versus concomitant and sequential cetuximab treatment). Secondary objectives are to determine the role and the mechanism of cetuximab in patient's chemoradiation regimen, the response rate, the potential of this combined modality treatment to concert locally advanced lesions to potentially resectable lesions, the time to progression interval and the quality of life.

[Stereotactic radiation therapy for liver metastases]. / Stereotaktische Strahlentherapie von Lebermetastasen.

Advances in radiation oncology made possible the locally curative treatment approach of stereotactically guided radiation therapy of liver tumours. Results of this highly focussed therapy were published by only a few centres. The radiation dose is delivered in one or a few fractions with high single doses. All published results show high local tumour control with low treatment morbidity. The treatment results of this noninvasive technique are similar to those of minimally invasive ablative therapies. Our own and other published data are summarized and discussed. The long-term results of this technique are currently being evaluated in a prospective multicentre trial.

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. METHODS AND MATERIALS: Twenty-four patients with liver metastases were treated with single dose radiation therapy on 26 occasions using a self-developed stereotactic frame. Liver movement was reduced by abdominal pressure. The effectiveness was evaluated under fluoroscopy. CT scans were performed on the planning day and directly before treatment. Representative reference marks were chosen and the coordinates were calculated. In addition, the target displacement was quantitatively evaluated after treatment. RESULTS: Diaphragmal movement was reduced to median 7 mm (range: 3-13 mm). The final set-up accuracy of the body was limited to all of median 1.8 mm in latero-lateral direction (range: 0.3-5.0 mm) and 2.0 mm in anterior-posterior direction (0.8-3.8 mm). Deviations of the body in cranio-caudal direction were always less than the thickness of one CT slice (<5 mm). However, a repositioning was necessary in 16 occasions. The final target shift was median 1.6 mm (0.2-7.0 mm) in latero-lateral and 2.3 mm in anterior-posterior direction (0.0-6.3 mm). The median shift in cranio-caudal direction was 4.4 mm (0.0-10.0 mm). CONCLUSIONS: In patients with liver metastases, a high set-up accuracy of the body and the target can be achieved. This allows a high-dose focal radiotherapy of these lesions. However, a control CT scan should be performed directly before therapy to confirm set-up accuracy and possibly prompt necessary corrections.

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. RESULTS: Thirty-five (29%) of 119 patients from 14 MEN 2A kindreds had biochemical and pathologic evidence of hyperparathyroidism, with a mean follow-up of 14.7 years. The phenotypic expression of hyperparathyroidism was associated with germline mutations of the RET protooncogene at codons 634 and 618. At initial operation, 21 (62%) patients had a selective resection, eight (24%) had a subtotal resection, five (14%) had total parathyroidectomy with autotransplantation, and one had an inadvertent total parathyroidectomy. Twenty-seven (77%) patients were cured by the first operation. Persistent hyperparathyroidism occurred in three (8.6%) patients, and recurrent hyperparathyroidism occurred in five (14.3%) patients; both occurred only in patients treated with selective or subtotal resection. Permanent postoperative hypoparathyroidism occurred in six (21%) of 29 patients after selective or subtotal resection, in the one patient with inadvertent total parathyroidectomy, and in one (20%) of 5 patients treated with total parathyroidectomy and autotransplantation. CONCLUSIONS: Recurrent or persistent hyperparathyroidism occurs after selective or subtotal parathyroidectomy, as a result of either missed glands or interval development of neoplasia in previously normal parathyroid glands left in situ. Therefore we advocate total parathyroidectomy and heterotopic autotransplantation for patients with hyperparathyroidism and MEN 2A.

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). Signal intensities of cholines, creatines, N-acetyl aspartate, and the presence of lactate and lipid resonances were correlated to final diagnoses established by clinical and MR imaging follow-up, positron emission tomography studies, or biopsy/surgery. Statistical analysis was performed using the t test, linear discriminant analysis, and k nearest-neighbor method. RESULTS: Significantly increased signal intensity ratios I(tCho)/I(tCr) (P <.0001) and I(tCho)/I(NAA) (P <.0001) were observed in neoplastic (n = 34) compared with nonneoplastic lesions (n = 32) and contralateral normal brain (n = 33). Analysis of I(tCho)/I(tCr) and I(tCho)/I(NAA) data yielded correct retrospective classification as neoplastic and nonneoplastic in 82% and 81% of the lesions, respectively. Neither I(NAA)/I(tCr) nor signal intensitities of lactate or lipids were useful for differential diagnosis. CONCLUSION: Metabolic information provided by proton MR spectroscopy is useful for the differentiation of neoplastic and nonneoplastic brain lesions after stereotactic radiotherapy of brain tumors.

[Radiotherapy of hepatic metastases]. / Strahlentherapie von Lebermetastasen.

Non-invasive treatment of hepatic metastases has become a focal point of interdisciplinary oncology especially since the advent of stereotactic radiation techniques. Worldwide several centers have shown that this treatment is a curative and well tolerated regimen with excellent rates of local control. Modern devices which combine radiation therapy with imaging techniques (image-guided radiotherapy) in particular allow precise dose application, especially for hypofractionated treatment concepts requiring daily repositioning.

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. Unlike the MEN syndromes, patients with familial hypocalciuric hypercalcemia (FHH) have only hypercalcemia with no associated endocrinopathies. The hyperparathyroidism in patients with either of the MEN syndromes is managed by parathyroidectomy, whereas patients with FHH are managed nonoperatively. The specific genetic defects associated with MEN type 2 syndromes and FHH have been identified. They explain, in part, the clinical and pathophysiologic features of these diseases. The genetic defect causative of MEN type 1 will doubtless soon be found and thereby provide further insights into the molecular basis of calcium homeostasis. We will review the clinical presentation and the management of patients with these disorders. We will also review the recent molecular discoveries in MEN 2A, MEN 2B, and FHH, and define how they have altered the management of patients who have these syndromes.

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. High-grade gliomas (anaplastic astrocytomas and glioblastoma multiforme) have a poor prognosis. Treatment options are capable of prolonging the natural history of the disease, but the long-term survival is poor. This review discusses the different postoperative treatment options and the prognostic factors in low- and high-grade astrocytomas.

[Stereotactic irradiation of liver metastases]. / Stereotaktische Bestrahlung von Lebermetastasen.

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. RESULTS: There were no major side effects observed. The actuarial local control was 82% after 18 months. The median actuarial survival was 24 months. However, there was a significantly improved survival in patients without additional extrahepatic tumor manifestation at the time of treatment compared to those, who were treated in palliative intention (87% vs. 24% after 18 months, p = 0.001 (log-rank). CONCLUSION: Stereotactic single dose irradiation is a non-invasive and safe treatment option for patients with inoperable liver metastases. Phase III studies will further evaluate this new approach.

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. The expression of p53 was determined by immunohistochemistry in 19 pheochromocytomas and in 17 MTCs using two antibodies (D01 and D07) on frozen and paraffin-embedded tissues. Four of the 22 pheochromocytomas and none of the MTCs showed LOH on 17p. No mutations were detected in any of the tumors screened by SSCV analysis. Immunohistochemical staining of frozen and paraffin-embedded tumor sections did not show p53 overexpression in any of the tumors examined. Our findings indicate that mutations in the TP53 gene are an uncommon event in the tumorigenesis of pheochromocytomas and medullary thyroid carcinomas.

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). In contrast, proton MR spectroscopy (1H-MRS) indicated radiation necrosis, which was confirmed histopathologically in surgical specimens. Subsequent follow-up examinations up to 19 months after surgery showed no evidence of tumor recurrence.

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. A limited number of MSH2 and MLH1 mutations have been described for sporadic colorectal cancers. In this study, we screened 12 primary sporadic colorectal cancers with microsatellite instability for mutations in MSH2 and MLH1 by using reverse transcription-polymerase chain reaction (RT-PCR) and single-strand-conformation-variant (SSCV) analysis. Eight mutations were identified in six tumors. One mutation in MLH1 was found to be present in the patient's germline DNA. Four tumors had somatic mutations in MLH1, and, in two of these tumors, two different mutations were identified. A single tumor had a somatic MSH2 mutation. Our observations suggest that MLH1 is mutated more frequently than MSH2 in sporadic colorectal cancers with microsatellite instability.

[First experiences with a noninvasive patient set-up system for radiotherapy of the prostate]. / Erste Erfahrungen mit einem nichtinvasiven Patientenfixierungssystem für die stereotaktische Strahlentherapie der Prostata.

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. Sixteen CT-studies (> or = 25 slices, thickness: 3 mm) of 2 patients who were immobilized for IMRT of prostate tumors were evaluated with respect to set-up accuracy of bony structures and the prostate itself. CT-studies were performed immediately before or after a treatment fraction. Deviations of bony landmarks and anatomical landmarks inside the planning target volume were measured in all 3 dimensions. RESULTS: Mean patient movements of 0.15 +/- 0.3 mm (latero-lateral), 0.9 +/- 1 mm (anterior-posterior), 1 +/- 1 mm (tranversal vectorial error) and < 3 mm slice thickness (craniocaudal) were recorded using bony landmarks and 0.9 +/- 0.9 mm (latero-lateral), 1.8 +/- 1.5 mm (anterior-posterior), 2.2 +/- 1.5 mm (transversal vectorial error) and < 3 mm (craniocaudal) using the confines of, or landmarks within the prostate. Standard deviations of absolute positioning error as an often used metric for positioning accuracy ranged between 0.3 and 1.7 mm in the transversal plane. The worst case transversal vectorial deviation for the prostate was 4.4 mm. Figure 4 summarizes the set-up accuracy of bony landmarks and the prostate. CONCLUSION: The presented combination of a body cast and head mask system in a rigid stereotactic body frame ensures reliable noninvasive patient fixation for fractionated extracranial stereotactic radiotherapy. It provides precise and reliable positioning of the prostate and meets the requirements for highly conformal radiotherapy such as IMRT. No further improvement of repositioning can be achieved with external immobilization devices since the positioning error of the target relative to the skeleton exceeds the accuracy of the positioning of the skeleton itself.

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. The effect of methylation of the MGMT promoter on gene expression and carcinogenesis in primary tumors is unknown. We investigated methylation of the MGMT promoter region in primary colorectal cancers and normal colonic mucosa. We used five methylation-sensitive restriction enzymes (BssHII, SacII, Eagl, Nael, and Smal) and Southern blot analysis to assess methylation in 46 cancers and 22 controls. Methylation of Eagl and Nael sites was seen in 12 tumors but in none of the 22 normal colorectal mucosa specimens. This difference was statistically significant (P<0.01). Methylation-sensitive single-nucleotide primer extension analysis of four additional cytosine residues confirmed methylation of the promoter region in the tumors identified by Eagl and Nael digestions and served to further quantitate the extent of methylation. Western blot analysis of 21 tumors revealed statistically significant lower MGMT expression in the eight tumors with methylation of the Eagl and Nael sites and nt -128 than in the 13 tumors lacking the methylation pattern (P<0.05). MGMT activity was lower in tumors with methylation than in tumors that were not methylated. The difference was not, however, statistically significant. We conclude that a subset of colorectal tumors is characterized by a specific methylation pattern in the MGMT promoter associated with reduced MGMT expression.