PubMed Health⌕ Search

Biomedical subjects

S Dinges

Publications and source records attributed to S Dinges.

26 records · Page 2Linked to original sources

Local recurrences of soft tissue sarcomas in adults: a retrospective analysis of prognostic factors in 102 cases after surgery and radiation therapy.

Between 1974 and 1990, 102 adult patients (age 18-86 years) with the diagnosis of a soft tissue sarcoma (STS) were treated with photons and/or electrons in combination with surgery. The total doses in the initial treatment volume (second order target volume) was 40-50 Gy. For the coning down volume (first order target volume) the median total dose was 59 Gy (range 45-72 Gy). A total of 18% (18/102) local failures was observed. In multivariate analysis, prognostic factors for the occurrence of a local failure were identified as follows: treatment of a primary or recurrent STS (P = 0.02), total dose (P = 0.025) and tumour grade (P = 0.05). Mode of surgery, tumour size (trunk versus extremity), pre- or postoperative radiotherapy, combined chemotherapy and tumour size (T1 versus T2) had no significant impact on the local relapse-free survival. These data give further evidence that combined surgery and radiotherapy is an effective modality in treatment of soft tissue sarcomas.

Adolescent↗

[Accelerated hyperfractionated radiotherapy combined with simultaneous chemotherapy in locally advanced pharyngeal and oral carcinomas].

PURPOSE: To evaluate the feasibility and effectiveness of a concurrent radio-chemotherapy regimen for locally advanced carcinomas of the pharynx and floor of the mouth. PATIENTS AND METHODS: Since January 1990, 97 patients with locally advanced carcinomas of the naso-, oro-, hypopharynx and the oral cavity in UICC stages III and IV were treated according to an accelerated hyperfractionated radiotherapy schedule with concurrent chemotherapy. The primary tumor and positive lymph nodes received a total dose of 72 Gy in 6 weeks. In the first 3 weeks, large fields were irradiated 5 times per week with 2 Gy per fraction. Thereafter, treatment was accelerated, giving 2 daily fractions of 1.4 Gy with minimal intervals of 6 hours. Target volumes were reduced after 49.6 and 59.4 Gy, excluding clinically uninvolved lymph node regions of low and high risk. On day 1, 350 mg/m2 5-FU and 50 mg/m2 folinic acid were given as intravenous bolus followed by continuous infusion of 350 mg/m2 5-FU and 100 mg/m2 folinic acid, days 1 to 5. 10 mg/m2 mitomycin C was given on day 5 and 36 of the treatment. Salvage surgery was offered for residual disease 5 to 6 weeks after the end of radiotherapy. PATIENT CHARACTERISTICS: 70 male, 27 female; age: 27 to 81 years; T2/T3/T4: 7/30/60; N0/N1/N2/N3: 20/18/53/6; nasopharynx/oropharynx/hypopharynx/oral cavity: 16/33/36/12. Median follow-up is 26 months. RESULTS: Overall survival and recurrence-free survival at 2 years were RESULTS: Overall survival and recurrence-free survival at 2 years were 68 +/- 5% and 74 +/- 5%. Multivariate analysis revealed a significant influence of the geometric mean neck node diameter or the N-stage on loco-regional control and survival. T-stage, tumor volume, or tumor localisation did not become significant. Acute toxicity of this schedule was acceptable but required optimised supportive care. Treatment related grade 4+ late toxicity of mucosa, soft tissue and bone were observed with a cumulative frequency of 13% at 2 years. Two patients died during a phase of severe leuko- or thrombocytopenia. CONCLUSION: This phase I to II trial shows favourable results using an intensified treatment radio-chemotherapy protocol. A phase III study is now planned, comparing this regime with an accelerated hyperfractionated radio-therapy alone to an increased total dose of 77.6 Gy.

Adult↗

The TCD50 and regrowth delay assay in human tumor xenografts: differences and implications.

The response to irradiation of five human xenograft cell lines--a malignant paraganglioma, a neurogenic sarcoma, a malignant histiocytoma, a primary lymphoma of the brain, and a squamous cell carcinoma--were tested in nude mice. All mice underwent 5 Gy whole body irradiation prior to xenotransplantation to minimize the residual immune response. The subcutaneous tumors were irradiated at a tumor volume of 120mm3 under acutely hypoxic conditions with single doses between 8 Gy and 80 Gy depending on the expected radiation sensitivity of the tumor line. Endpoints of the study were the tumor control dose 50% (TCD50) and the regrowth delay endpoints growth delay, specific growth delay, and the tumor bed effect corrected specific growth delay. Specific growth delay and corrected specific growth delay at 76% of the TCD50 was used in order to compare the data to previously published data from spheroids. The lowest TCD50 was found in the lymphoma with 24.9 Gy, whereas the TCD50 of the soft tissue sarcomas and the squamous cell carcinoma ranged from 57.8 Gy to 65.6 Gy. The isoeffective dose levels for the induction of 30 days growth delay, a specific growth delay of 3, and a corrected specific growth delay of 3 ranged from 15.5 Gy (ECL1) to 37.1 Gy (FADU), from 7.2 Gy (ENE2) to 45.6 Gy (EPG1) and from 9.2 Gy (ENE2) to 37.6 Gy (EPG1), respectively. The corrected specific growth delay at 76% of the TCD50 was correlated with the number of tumor rescue units per 100 cells in spheroids, which was available for three tumor lines, and with the tumor doubling time in xenografts (n = 5). The TCD50 values corresponded better to the clinical experience than the regrowth delay data. There was no correlation between TCD50 and any of the regrowth delay endpoints. This missing correlation was most likely a result of large differences in the number of tumor rescue units in human xenografts of the same size.

Animals↗

[Malignant paragangliomas--the results of radiotherapy in 6 patients].

Between February 1984 and May 1989, six patients (four male, two female) with malignant paragangliomas of the carotid body (n = 4) and glomus jugulare (n = 2) were irradiated in the Department of Radiation Oncology at Essen University. All patients had macroscopic (residual) tumor at the start of treatment. Five out of six paragangliomas had to be considered malignant, since histological lymph node involvement or distant metastasis was confirmed. In the sixth case extra- and intracranial tumor growth was observed. Total doses between 40 and 55 Gy using cobalt 60, 10 or 15 MeV photons were administered. Radiation therapy was canceled at 30.6 Gy in one patient because of multiple distant metastasis. Three out of four patients, who received curative treatments, were locally controlled (25 to 91 months). A local recurrence in one patient was detected 18 months after irradiation; this patient died of distant metastasis 23 months after treatment. In one out of two palliatively irradiated patients, local control could be achieved until the patient died of distant metastasis twelve months after treatment. Grade III- or grade IV-treatment toxicity was not observed. Radiation therapy of malignant paragangliomas with doses between 45 and 54 Gy in five to six weeks is an effective treatment with low toxicity and should be preferred to surgery in glomus jugulare and advanced carotid body tumors.

Adult↗

[Radiotherapeutic strategies for soft tissue sarcomas in adults].

Soft tissue sarcomas account for under 1% of all cancers in adults. Most soft tissue tumours are benign, only about 1% being characterized clinically and histomorphologically as malignant neoplasms. Since these tumours are often treated by excisional biopsies without any further diagnostic imaging, precise planning of postoperative irradiation therapy is often difficult to achieve. Therefore, all soft tissue tumours with a short history should be regarded as malignant until the contrary has been proven. In general, the mode of tumour resection should be postponed until CT or MR diagnosis is complete and a biopsy of the tumour has been carried out. Whereas benign lesions need only marginal tumour resection, malignant lesions require considerable safety margins. In soft tissue sarcomas of the extremities, which account for 50-60% of all sarcomas, a wide local resection followed by postoperative irradiation with about 66 Gy can guarantee local control rates above 80% and preserve the function of the limb. Radical surgery alone can achieve the same local control, but without the high level of functional integrity. In the case of marginally resectable tumours, preoperative irradiation can induce partial tumour remission and thus allow definitive limb-sparing tumour resection. Recently, multimodal and neoadjuvant therapeutic strategies have been developed. The efficacy of these experimental strategies is not yet proven.

Adult↗

Neutron boost irradiation of soft tissue and chondrosarcomas at the West German Tumour Centre in Essen.

In this retrospective study, the results of postoperative neutron boost therapy for 40 soft tissue- and 18 chondrosarcomas are presented. In 65.5% and 34.5% of all cases, microscopic to macroscopic tumour residual was left postoperatively. Locally advanced and moderate to highly malignant tumours were found at surgery in 81% and 69%, respectively. Except for seven patients with a whole series of neutrons to 16 Gy, the other cases were treated with initially 40 to 50 Gy photons and a subsequent neutron boost of 4 to 6 Gy. The median follow-up was 29.3 and 36.2 months for the soft tissue- and chondrosarcomas. The actuarial three-year local control and overall survival rates were 69.3% and 91% for soft tissue- vs. 55.6% and 62.9% for chondrosarcomas. With regard to the extension of surgery (microscopic or macroscopic residual), local control rates of 80% and 60% for soft tissue- vs. 62.5% and 40% for chondrosarcomas were observed. The overall local failure rate was 32.8% with a median disease-free interval of ten respectively eleven months for soft tissue and chondrosarcomas. 17 out of 19 local recurrences were due to inadequate irradiation portals for the neutron boost or to insufficient total doses in the initially treated photon target volume.

Actuarial Analysis↗