Coverage of anterior fossa in whole-brain irradiation.

PURPOSE: Whole-brain irradiation is indispensable in the treatment of several brain tumors and requires coverage of the entire subarachnoid space. Retrospective studies have revealed frequent recurrences in the frontobasal fossa above the cribriform plate (CP). We sought to determine how accurately the latter could actually be identified on lateral radiographs such as those used for radiotherapy planning. METHODS AND MATERIALS: The CP was localized by five radiation oncologists and five radiologists on lateral radiographs of 30 human skulls from an anatomic collection. Reference radiographs were acquired under identical conditions except for lead markers pointing to the CP and the ethmoid cells. The targeting accuracy was analyzed. RESULTS: In 39% (n = 116), the location of the CP was correctly estimated within 2 mm. Mislocations of 2-5, 5-10, and >10 mm were noted in 34% (n = 102), 20% (n = 61), and 7% (n = 21), respectively. Neither specialty nor experience (years of training) exerted a significant influence on targeting accuracy. If the roofs of the ethmoid cells formed prominent bony edges, they were mistaken for the CP in 37%. CONCLUSION: Lateral radiographs provide insufficient information to locate the CP accurately in whole brain irradiation. Additionally, localization was significantly impaired by prominent ethmoid cells.

Gene expression profiling of advanced head and neck squamous cell carcinomas and two squamous cell carcinoma cell lines under radio/chemotherapy using cDNA arrays.

BACKGROUND AND PURPOSE: The response of squamous cell carcinomas of the head and neck (HNSCC) to radio/chemotherapy is accompanied by complex changes in patterns of gene expression. It is highly probable that a better understanding of molecular and genetic changes can help to optimize the treatment of HNSCC. cDNA arrays provide a powerful tool for high-throughput monitoring of gene expression in small clinical specimens. MATERIALS AND METHODS: We used tumour biopsies from four patients with HNSCC which have been taken prior to and during radio/chemotherapy. The patterns of gene expression obtained from clinical samples were compared with gene expression profiles of two squamous cell carcinoma cell lines (FaDU and UD-7A). RESULTS: The experimental data analysis revealed changes in expression levels of several genes during radio/chemotherapy. Despite treatment, independent samples taken from the same cell line or tumour in situ were more similar to each other than either was to other specimens. The data indicate a high gene heterogeneity of HNSCC that is preserved during treatment. CONCLUSIONS: From our preliminary results we conclude that the cDNA array experimental approach can detect differences in gene expression between treated and untreated small tumour biopsies, as well as inter-individual differences in expression profiles between HNSCC tumours. The examination of a greater sample size will be needed to make this preliminary evaluation useful to elucidate the functional significance of individual genes which exhibit altered levels of expression under radiation therapy.

Remission rates in breast cancer treated with preoperative chemotherapy and radiotherapy.

PURPOSE: Evaluation of remission rates after neoadjuvant chemotherapy alone or followed by preoperative radiotherapy. PATIENTS AND METHODS: 194 women with 198 biopsy-proven breast tumors were evaluated in this retrospective study. Of the 198 cases evaluated, 64 received neoadjuvant chemotherapy followed by surgery and adjuvant irradiation (CT group). In 134 cases, sequential preoperative chemo-/radiotherapy (CT-RT group) was given. In both groups, endocrine treatment was initiated in case of positive hormone receptor status after chemotherapy. The whole breast was homogeneously irradiated using 2-Gy fractions up to a total dose of 50 Gy, followed by a boost of 6-11 Gy to the tumor. RESULTS: A histologically proven complete remission (pCR) was achieved in 3% (2/64) in the CT and in 42% (56/134) in the CTRT group. The logistic regression analysis, including clinical tumor category (cT), lymph node (cN) and metastasis status (cM), grading (G), hormone receptor status (HRS), number of preoperative chemotherapy cycles, preoperative tumor volume, and preoperative radiotherapy, revealed that HRS (p = 0.0232) and radiotherapy (p < 0.0001) were significant factors for achieving pCR. CONCLUSION: Combination of neoadjuvant chemo-/radiotherapy results in significantly higher rates of complete remission than neoadjuvant chemotherapy alone. The significance for tumor-free and overall survival has to be evaluated.

Radiosensitivity and TP 53, EGFR amplification and LOH10 analysis of primary glioma cell cultures.

AIM: Determination of in-vitro radiosensitivity and genetic alterations of cell cultures derived from human glioma biopsy tissue and established glioma cell lines. MATERIAL AND METHODS: Fresh brain tumor specimens of six patients were processed to early passage cell cultures. In addition the cell lines D 384 and Gli 6 were used. Cell cultures were irradiated with doses from 2 to 10 Gy. Following irradiation, cell survival was determined by clonogenic assay and survival curves were generated. The surviving fractions after 2 Gy (SF2) and 4 Gy (SF4) were used as radiosensitivity parameters. Genetic analysis included determination of the mutational and loss of heterozygosity (LOH) status of TP 53 (exons 5-8), the LOH 10- and epidermal growth factor receptor gene (EGFR) amplification status. RESULTS: The SF2 and SF4 values ranged from 0.54 to 0.88 (mean: 0.70) and from 0.13 to 0.52 (mean: 0.32), respectively. Genetic alterations were found in the Gli 6 cell line and in two primary cell cultures. The genetic profile of Gli 6 showed LOH but no TP 53 mutation, complete LOH 10 and no EGFR amplification. The VU 15 cell culture showed TP 53 mutation but no LOH 10 or EGFR amplification, while VU 24 showed incomplete LOH 10, EGFR amplification and no TP 53 mutation. In the other four cell cultures and D 384 cell line no genetic alterations were diagnosed. Histopathological classification of glioblastoma multiforme and/or genetic alterations resulted in lower radiosensitivity. CONCLUSION: In this small series of early passage glioma cell cultures low radiosensitivity and alterations in cell regulatory genes were seen. Further testing of biological behavior in larger series of patient-derived material is ongoing.