PubMed Health⌕ Search

Biomedical subjects

R Greiner

Publications and source records attributed to R Greiner.

At least 37 records · Page 2Linked to original sources
PubMed1996

Stoma recurrence after laryngectomy: an analysis of risk factors.

Data from 130 patients who underwent total laryngectomy for squamous cell carcinoma of the larynx were reviewed. Patients were treated either by primary laryngectomy and planned postoperative radiotherapy or by primary radiotherapy and subsequent salvage laryngectomy. Patients with other treatment modalities and patients with positive margins of resection and laryngectomies for hypopharyngeal cancers were excluded from the study. The stomal recurrence rate with reference to several risk factors, such as primary tumor stage, location of tumor, lymph node metastases, timing of tracheotomy, and presence of a postoperative pharyngoperistomal fistula, was analyzed. The overall incidence of stomal recurrence was 10%. The treatment modality appeared to have an impact on subsequent stomal recurrence: stomal recurrence developed more often after salvage laryngectomy (18.4%) than after primary laryngectomy with planned postoperative radiation (4.8%). Advanced T stage, N stage, subglottic involvement, and preoperative tracheotomy are risk factors for stomal recurrence only in patients with a primary laryngectomy. Stomal recurrence developed in only four patients after primary laryngectomy with planned radiation. All four patients had more than one risk factor: primary tumor stage T4 (four times), subglottic involvement (three times), and preoperative tracheotomy (three times). The presence of a postoperative pharyngoperistomal fistula likewise may represent a risk factor for the development of a stomal recurrence.

Carcinoma, Squamous Cell↗
PubMed1996

Treatment of ovarian cancer with surgery, short-course chemotherapy and whole abdominal radiation.

BACKGROUND: The primary aim was to induce a high number of pCR in early (FIGO IC, IIB + C) - and advanced (FIGO III-IV) - stage ovarian cancer with a surgery plus 4 cycles of cisplatin and melphalan (PAMP) regimen. The second objective was to prevent relapse with WAR in patients in remission after chemotherapy. PATIENTS AND METHODS: 218 eligible patients were treated after staging laparotomy with cisplatin 80 mg/sqm i.v. on day 1 and melphalan 12 mg/sqm i.v. on day 2 q 4 weeks. Response was verified by second-look laparotomy. WAR was carried out with the open field technique on a linear accelerator (daily dose: 1.3 Gy, total dose: 29.9 Gy) in patients with pathological or clinical CR or pathological PR with microscopical residual disease. RESULTS: 146/218 patients (67%, 95% CI: 61%-73%) responded to PAMP: 56 (26%) achieved pCR, 24 (11%), cCR, 56 (26%) pPR and 10 (5%) cPR (c = clinical, p = pathological). Multivariate analyses revealed that in advanced stages (92 cases in remission), the achievement of pCR was the most important factor for longer time to failure (TTF) and survival. Only 51/118 (43%) patients in remission received WAR. Early-stage patients <= 55 years were more likely to have WAR than patients older than 55 years (77% vs. 23%; p = 0.02). Advanced-stage patients with cCR were less likely to be irradiated than patients with pCR or pPR (10% vs. 51%; p = 0.003). Toxicity of PAMP was acceptable with 10% of WHO grade 4 hematologic toxicity. Acute hematological toxicity of WAR caused interruption (33%) or incompleteness (33%) of irradiation in the majority of patients. CONCLUSIONS: PAMP is an effective treatment for advanced ovarian cancer with a 67% response rate after 4 cycles. For the majority of patients in remission, WAR as a consolidation treatment was hardly feasible. For these patients new treatment modalities to consolidate remission are needed.

Adult↗
PubMed1995

[Participation in multicenter studies as quality control in the therapy of Hodgkin disease: an interim report].

UNLABELLED: From 1988 to 1992 the Swiss Group for Clinical Cancer Research (SAKK) entered 113 patients with Hodgkin's disease into three stage adapted trials (HD-4-6) from the German Hodgkin Study Group (DHSG). In an interim analysis freedom from treatment failure (FFTF) and overall survival (OS) of the SAKK patients (SAKK-pt) were compared to the remaining study population (GHSH-pt) (median follow-up: 30 months for HD-4 and HD-5, 24 months for HD-6). RESULTS: HD-4: SAKK (n = 16), DHSG (n = 241), FFTF-SAKK: 100%, FFTF-DHSG: 85%, p: ns, OS-SAKK: 100%, OS-DHSG: 99%, p: ns, HD-5: SAKK (n = 66), DHSG (n = 639), FFTF-SAKK: 90%, FFTF-DHSG: 85%, p: ns, OS-SAKK: 93%, OS-DHSG: 95%, p: ns, HD-6; SAKK (n = 31), DHSG (n = 411): FFTF-SAKK: 62%, FFTF-DHSG: 68%, p: ns, OS-SAKK: 70%, OS-DHSG: 88%, p < 0.008. The results in the SAKK patients with advanced disease are unsatisfactory. Despite the fact that the treatment was given on time with full doses, 10/30 patients achieved no complete remission (CR). Only one patient relapsed after an initial CR. 6 patients had primary progressive disease. 6 patients died despite conventional salvage chemotherapy. High dose chemotherapy/autologous bone marrow transplantation (HDC/ABMT) was only given to 3 out of 8 potential candidates. Only 2/11 patients are still alive and disease-free after relapse or initial progression. Both had received HDC/ABMT as part of their salvage regimen. This interim analysis identifies a group of patients in which treatment strategies need to be optimized.

Adult↗
PubMed1995

Curative treatment of clinical stage II endometrial carcinoma.

In a retrospective study of 54 patients we compared three treatment policies of clinical stage II endometrial carcinoma: One group of patients (n = 29) was surgically staged with histological examination made at surgery and treated by abdominal total hysterectomy with bilateral salpingo-oophorectomy. In case of cervical infiltration by tumour, a pelvic node sampling was added. The second group was treated by radical hysterectomy (n = 9) and the third group of patients (n = 16) was treated by abdominal total hysterectomy with bilateral oophorectomy only. The median follow-up time was 68 months. The overall five year-survival was 64%. The overall five year-survival rates according to surgical procedure were not significantly different. The survival curves were significantly different from each other as were those according to surgical stage and age. In a multivariant analysis stage, grading and age proved to have an independent relation with the survival rate whereas type of surgical procedure, depth of myometrial infiltration and type of radiotherapy had no influence on survival. Intraoperative histological staging allows adaption of treatment to the true stage, thus minimising treatment-related morbidity.

Adult↗
PubMed1994

First isolated locoregional recurrence following mastectomy for breast cancer: results of a phase III multicenter study comparing systemic treatment with observation after excision and radiation. Swiss Group for Clinical Cancer Research.

PURPOSE: We performed a randomized phase III multicenter study to compare systemic treatment versus no treatment after complete excision and radiotherapy for isolated first locoregional recurrence in patients with breast cancer. PATIENTS AND METHODS: One hundred sixty-seven good-risk patients with an estrogen receptor (ER+) positive recurrence or, in case of unknown receptor status, a disease-free interval (DFI) of greater than 12 months and < or = three recurrent tumor nodules each < or = 3 cm in diameter were entered onto the study. They were randomized to observation subsequent to local treatment or to receive tamoxifen (TAM) until disease progression. Seventy-nine percent of the patients were postmenopausal. RESULTS: The median observation period for the entire study population was 6.3 years. The median disease-free survival (DFS) duration was 26 months for observation and 82 months for TAM patients (P = .007). This was mainly due to the reduction of further local recurrences, whereas the occurrence of early distant metastases was delayed. A multivariate analysis identified DFI and treatment with TAM as significant prognostic factors for DFS. The 5-year overall survival (OS) rates were 76% and 74%, respectively (P = .77). DFI was also a prognostic factor for OS. CONCLUSION: Systemic therapy with TAM after isolated locoregional recurrence of breast cancer significantly increased 5-year DFS rates from 36% to 59% compared with observation alone and prolonged median DFS by more than 4.5 years in patients with ER+ tumors or in the case of unknown ER status with a DFI of greater than 12 months and minimal tumor burden. Treatment with TAM currently has no significant impact on OS, but the median survival duration of the study population has not yet been reached.

Adult↗
PubMed1994

Enhancement in irradiated mononuclear cells in culture of mitogen-induced incorporation of [3H]thymidine by homologous conditioned medium.

Incorporation of [3H]thymidine in irradiated peripheral blood mononuclear cell cultures irradiated in vitro was stimulate significantly by either concanavalin A or phytohemagglutinin only in the presence of homologous conditioned medium. Production of this activity by mononuclear cells was enhanced by irradiation and/or pulsed exposure to puromycin but was abolished by actinomycin D. Addition of anti-interleukin 1 or anti-interleukin 2 monoclonal antibodies to the conditioned medium before assay did not influence the stimulatory action. A similar significant stimulation of mononuclear cell cultures irradiated with 5 Gy by concanavalin A was obtained when purified preparations of homologous conditioned medium were used in the assay. Purification was done by ultrafiltration and concentration, heparin agarose chromatography, ammonium sulfate precipitation, concanavalin A agarose chromatography, DEAE-ion exchange chromatography and HPLC gel filtration chromatography. With SDS-PAGE and silver staining, the active HPLC fraction gave one band of 50 kDa, suggesting that this protein is responsible for the co-stimulatory effect of homologous conditioned medium for both mitogen-induced irradiated and nonirradiated mononuclear cell cultures.

Adult↗
PubMed1993

Purification and characterization of two phytases from Escherichia coli.

Two periplasmatic phytases, called P1 and P2, were purified about 16,500-fold to an apparent homogeneity with a recovery of 7 and 18%, respectively. The enzymes behave as monomeric proteins with molecular masses of about 42 kDa. Because of the limited amounts recovered, the amino terminal sequence of only one of the phytases was determined. Both enzymes are very specific for phytate and have little or no activity on other phosphate esters tested. The kinetic parameters for the hydrolysis of Na-phytate and p-nitrophenyl phosphate are kcat/KM 478 x 10(5) s-1 M-1 and 0.6 x 10(5) s-1 M-1 at pH 4.5. The hydrolysis pathway for phytate was elucidated for P2; consequently, this enzyme is a 6-phytase. The chemical and kinetic properties of the purified phytase P2 points to an identity with an enzyme described by Dassa et al. (1982, J. Biol. Chem. 257, 6669-6676) as a pH 2.5 acid phosphatase. Because of the kinetic parameters it would be better to denote this enzyme as a phytase.

6-Phytase↗
PubMed1992

[Sphincter-preserving radiotherapy of anal carcinoma].

During the last decade radiotherapy, in combination with chemotherapy, has become the treatment of choice in cure of anal carcinoma with preservation of anal function, and has replaced abdominoperineal resection (APR). From 1979-1990 54 patients with anal carcinoma were treated by radiotherapy. 24 patients received radiotherapy after APR (12 adjuvant, 12 after recurrence). 11 received palliative radiotherapy without prior APR. 19 patients were treated curatively, 17 of whom received a combination of external irradiation followed by interstitial iridium implantation in a split course regimen. 11 of the 19 patients received short simultaneous chemotherapy (mitomycin C and 5-fluorouracil). All 19 patients had a complete remission. 18/19 patients had no local recurrence after mean 14 months' follow-up. 2 patients developed regional recurrence. 3 patients died of other causes. Colostomy was necessary in 5/19 patients with anal necrosis which was dose-related. The maximum tolerated dose was 71.4 Gy. Our results support the recommendation in the literature of primary, curative, radiotherapy and chemotherapy of anal carcinoma with preservation of the anal sphincter.

Adult↗
PubMed1991

[Interdisciplinary communication in breast-preserving therapy of early infiltrating ductal breast carcinoma].

The goal in breast-maintaining treatment of early mammary cancer means control of the tumor in a cosmetically acceptable breast worthy to be left in place. To this intent, a staged approach with agreement between therapists (surgeon, radiotherapist, oncologist) and pathologist should be used. Morphologic and histopathologic findings are relevant and are age-dependent indicators for risk of local recurrence. The cosmetic result as well as local tumor control depend on clinical findings and techniques of resection. The interdisciplinary communication weighs clinical and morphological criteria for counselling and selection of patients. In the presence of unfavourable prerequisites for cosmetically satisfactory results and increased probability of local recurrence (greater than 20%/5 years), breast-maintaining therapy should not be recommended; however, prognostic criteria do not depend on operative techniques.

Age Factors↗
PubMed1990

[Ovarian carcinoma: current therapeutic aspects. A review].

Ovarian cancer is the leading cause of gynaecologic cancer death and the fourth most frequent cause of cancer death in women. 70% of all ovarian cancers will be diagnosed only at an advanced stage of the disease despite the improvements in diagnostic tools. Standard therapeutic concepts and new therapeutic modalities are discussed. Staging laparotomy with cytoreductive surgery is the most important part of initial patient management. Second-look operation has recently come under criticism, as it probably offers only minor therapeutic benefit. However, it remains the golden rule for evaluating different therapy modalities in the setting of a clinical trial. After surgery, chemotherapy is indicated for all patients with ovarian cancer FIGO stage III and IV. The question whether all patients with stage I and II disease need additional treatment remains unresolved. The standard regimen for patients with advanced ovarian cancer consists of six months' chemotherapy with a combination of cisplatin and an alkylating agent. Current cisplatin containing regimens achieve a clinical response rate of 60-80% and a documented pathologic complete response rate of 30% overall. Despite higher overall response rates and increased disease-free survival rates with cisplatinum combinations, long term survival is not significantly altered. Investigative approaches with intraperitoneal chemotherapy, biologic response modifiers and drug resistance modifiers may open new therapeutic avenues for this challenging disease. Radiotherapy (open field technique) also represents a highly active and curative treatment modality for certain ovarian cancer patients. Nowadays radiotherapy is mainly used as adjuvant treatment for patients with low risk early stage disease and as consolidation treatment for patients with complete remission after chemotherapy and second-look operation.

Adult↗
PubMed1990

Anaplastic astrocytoma and glioblastoma: pion irradiation with the dynamic conformation technique at the Swiss Institute for Nuclear Research (SIN).

Clinical phase I/II studies have been performed at the Swiss Institute for Nuclear Research (SIN) since February 1982. Fifty-two out of 249 patients accepted for pion treatment by the end of 1986 were treated for malignant glioma with high dose pion irradiation. A substantial influence of their radioresistance was expected from increased radiation quality due to the contribution of high LET particles from pion capture, and by the possibility of target volume shaping and dose distribution related to the dynamic spot-scan conformation technique. The patients' treatment followed a dose escalation program with total doses from 2720-3420 cGy, fraction sizes from 170 to 205 cGy (90% isodose, minimum target dose), and treatment times from 4 to 5 weeks. 12/52 patients received an accelerated treatment with 3280 cGy in 14-22 days. 49/52 patients are eligible: 3 with astrocytoma of clinical aggressive behaviour, 14 with anaplastic astrocytoma (median age 42 years), and 32 patients with glioblastoma (median age 52 years). 8/49 patients had total/subtotal tumour resection, 19 patients a stereotactic biopsy. The patients were divided into three groups according to total dose, and a fourth group which received the accelerated treatment. There was no statistically significant difference in the median survival rate between the four groups, which was 13 months for the non-glioblastoma patients and 9 months for the glioblastoma patients. No radiation necrosis and no demyelination was found in 17 patients (6 recraniotomies, 11 autopsies). In 10/17 patients, clearly identifiable tumour cells were not demonstrated. NMR findings showed the tumour-surrounding oedema mostly stimulated by tumour necrosis and tumour progression. From these findings, further dose escalation programs, together with a shaping of the target volume close to the tumour, are not contraindicated.

Adult↗
PubMed1990

Tissue characterization of brain tumors during and after pion radiation therapy.

Negative Pi-mesons (pions) are applied at the Paul Scherrer Institute in the radiotherapy of highly malignant gliomas using a dose escalation program. The therapy effects of 7 randomly selected patients were followed up by 62 MRI examinations. The quantification of the effects is based on the relaxation times T1 and T2, which are acquired by a new designed multi-echo multiple saturation recovery imaging technique. As a summary of the results, roughly two reaction types are observed. For both types the relaxation times increase up to two to three months after the radiation therapy. Then in one type (two patients) the T1 and T2 values of the tumors, and of the edemas surrounding the tumors, further increase, indicating an unfavorable prognosis. In the other type (five patients) the relaxation times drop down towards, or even below, their initial values, reflecting the onset of the reparation processes in the tissue. This later behaviour reflects an at least temporary control of the disease; that is, the short term prognosis for these patients is more favorable. It further can be concluded, with respect to our MR parameters, that the radiotolerance of healthy brain tissue is much higher than that of malignant glioma tissue, despite the fact that these tumors are very seldom definitively radiosensible.

Astrocytoma↗
PubMed1990

Spot scanning for 250 MeV protons.

Protons have a long tradition in precision treatment of lesions of limited size at limited depth. Recently interest has developed in hospital based proton therapy accelerators, able to treat deep seated tumors. Heavy charged particles, and especially protons, are particularly suited to treat well localized tumors. Protons can be collimated as precisely as photons, but in addition have a well defined range. Protons are therefore predestinated for conformation radiotherapy also for larger target volumes. At the Swiss Institute for Nuclear Research a computer optimized treatment planning system has been developed for pion radiotherapy. The principle of this dynamic treatment technique can be adapted for proton therapy. It could prove to be a valid alternative to passive scattering for proton treatment especially of large irregularly shaped volumes. Dose calculations have been performed for specific cases using a 250 MeV pencil beam. The dose distributions and dose volume histograms have been compared with pion therapy. A horizontal experimental beam line, using a degraded 590 MeV proton beam of the PSI ring cyclotron, is set up to verify calculations in phantoms.

Humans↗
PubMed1990

Pion irradiation at Paul Scherrer Institute. Results of dynamic treatment of unresectable soft tissue sarcoma.

Since November 1981, when pion irradiation was introduced for deep seated tumors at the Swiss Institute for Nuclear Research (SIN; now Paul Scherrer Institute, PSI) a dynamic, three-dimensional spot scan application technique has been in use. To exploit this technique a special planning system for optimisation of the dose distribution has been designed. From November 1981 to December 1988 a total of 406 patients have been treated with pions. From April 1983 to October 1987 a total of 35 patients were prospectively treated for unresectable soft tissue sarcomas in a phase I/II-study. In 32/35 patients, tumor sites were retroperitoneal, pelvic or in the groin or thigh. 27 patients received a high, curative total dose of 30 to 36 Gy. After a median follow-up time of 19 months (13 to 68) the actuarial five-year rate of local tumor control for these 27 patients was 64%; the actuarial five-year survival rate of the 20 patients treated without metastases was 58%. Late reactions appeared in 5/27 patients: 2/8 patients with extremity/groin sarcomas (1/2 caused by biopsy) and 3/19 patients with retroperitoneal/pelvic sarcomas (one a skin reaction after Actinomycin-D, one a small bowel reaction after 36 Gy, a dose no longer given). Dynamic spot scan pion irradiation proves to be a successful treatment technique for unresectable sarcomas with a high rate of tumor control and a very low rate of severe late reactions.

Aged↗
PubMed1989

[Radiotherapy of bronchus carcinoma].

In spite of the yet unsatisfactory results of curative therapy of lung cancer, surgeons, internists, oncologists and radio-oncologists are challenged to coordinate therapeutic efforts. The contribution of radio-oncology to this collaborative approach is reviewed in the context of tumor type and spread as well as the patients general condition and symptoms. The different fractionation-schemes used for hyperfractionated, accelerated and concomitant treatment-plans are dealt with in depth. Involved radiation therapy in lung cancer is tedious, technically demanding and requires educated consideration of arguments.

Carcinoma, Non-Small-Cell Lung↗
PubMed1988

[Loco-regional recurrence following surgery of breast carcinoma: prognostic factors and therapeutic consequences].

The course following local relapse after mastectomy was studied prospectively in 225 women. Factors significantly influencing the further course were determined. On the whole the prognosis was relatively good, with a projected 5-year relapse-free survival of 47%, a median time interval of 53 months until development of distant metastases, and an estimated death rate of 41% after 5 years. The most important factor influencing the incidence and time interval until appearance of distant metastases is the axillary lymph node status at the time of mastectomy. N0 patients have a much better prognosis than N+ patients in univariate as well as multivariate analysis. Other factors in univariate analysis which play a role in either the incidence of distant metastases or overall survival include estrogen receptor content, site of the local relapse (skin or regional lymph nodes), time interval between mastectomy and the occurrence of the local relapse, and number of tumor nodules in the local relapse. In multivariate analysis virtually the only really independent prognostic factors are primarily the initial axillary lymph node status for survival free of distant metastases and the time interval from mastectomy to local relapse for overall survival.

Breast Neoplasms↗
PubMed1988

Treatment of advanced ovarian cancer with surgery, chemotherapy, and consolidation of response by whole-abdominal radiotherapy.

Between April 1981 and June 1985, 195 patients with ovarian cancer, International Federation of Gynecology and Obstetrics (FIGO) Stages IIB, IIC, III, and IV, entered a trial that consisted of surgery and chemotherapy with cisplatin (P) and melphalan (PAM) with or without hexamethylmelamine (HexaPAMP or PAMP regimens) every 4 weeks for 6 cycles. Because the intent was to study the outcome by treatment after evaluation of first-line chemotherapy, patients were evaluable only if the response was assessed by a second-look operation or if measurable disease progression was documented. One hundred fifty-eight patients (81%) were evaluable for response. Forty-five (28%) achieved pathologically confirmed complete remissions (pCR), and 24 of these patients received whole-abdominal radiation (WAR) for consolidation of response. Five patients with complete remission after WAR relapsed, as did nine of the 21 with complete remission who had not undergone WAR. The 3-year time to progression percentage (TTP +/- SE) from second-look operation was 70% +/- 7% for all patients who achieved pCR, 83% +/- 8% for those who received WAR, and 49% +/- 15% for those who did not receive WAR (this was not a randomized comparison). The 3-year TTP percentage for the 49 partial responders was 21% +/- 6%, identical for the 19 who had WAR and the 30 who had no radiation therapy. Additional or alternative methods for consolidation of pCR are needed since patients continue to relapse despite optimal initial response to therapy.

Abdomen↗