[en] Cisplatin (CDDP) and radiotherapy are frequently used concomitantly in the treatment of various malignant conditions. Because of its toxicity, cisplatin tends to be replaced by carbo-platin (CBDCA) in several indications. Available data regarding the combined effects of cisplatin and carbo-platin with ionising radiation are contradictory. Various concentrations of cisplatin and carbo-platin and various timing of association with radiation have been tested in vitro in a human ovarian cancer cell line. The parental cell line (AOvC-0) and a cisplatin-resistant stable sub-line (AOvC-CDDP/O) (De Pooter et al., Cn Res, 1991) were exposed to carbo-platin (2.5, 5 and 10 M) and to CDDP (1, 2.5 and 5 M), 16 h and 4 h before and 4 h and 16 h after irradiation, respectively. Cell survival was evaluated by a classical clonogenic assay. Exposure of AOvC-0 to 5M CBDCA and of AOvC-CDDDP/O to 10 M CBDCA, before or shortly after radiation exposure, increased cell lethality in a clear supra-additive way, with the highest DEF in the shoulder region of the survival curve and at radiation doses relevant to clinical radiotherapy. In the sensitive cell line, 5 M carbo-platin resulted in an additional lethality equivalent to 4.5 Gy; in the resistant cells, 10M carbo-platin was equivalent to 3.6 Gy. Replacing carbo-platin by cisplatin in an identical set-up demonstrated exclusively simple additivity (DEF = 1). These data suggest that carbo-platin and cisplatin delivered at equi-toxic doses interact with radiation a different way and that, in the present set-up, only carbo-platin enhanced the effects of radiation. Carbo-platin might consequently be a better candidate than cisplatin in some concomitant combinations with radiotherapy. (authors)

[en] Paclitaxel is an agent which stabilizes microtubules, and has been shown to block different cells in the G2/M phase of the cell cycle and thus to modulate their radio-responsiveness. We investigated the radiosensitizing potential of paclitaxel in human head and neck cancer cells. ZMK-1 cells were incubated with paclitaxel for 3, 9, or 24 h before or during 24 h after irradiation. Paclitaxel concentrations of 70 nM, 7 nM, and 0.7 nM were chosen to obtain equivalent toxicity at the different incubation times: 3 h, 9 h, and 24 h, respectively. Radiation doses ranged from 0 to 8 Gy using ⁶⁰Co source. Cell survival was measured by a standard clonogenic assay after a 9-day incubation. Flow cytometry was used to measure the capacity of paclitaxel to accumulate cells in the G2/M phase. Paclitaxel alone possessed cytotoxicity dependant on time and concentration. There was a total of 40 % of cells accumulated in G2/M after 24-36 h. When combined with radiation, the 9 h preincubation resulted in a radio-sensibilizing. The 3 h pre-incubation as well as the 24 h post-incubation resulted in an infra-additive effect. In our cells a radiosensitizing effect of paclitaxel could not be demonstrated unambiguously. The blockage of the cells in he G2/M phase is not the only mechanism to explain the potential radiosensitization of paclitaxel. (authors)

[en] Retrospective study to analyze the results of external beam radiation treatment with or without surgery for loco--regional recurrence of adenocarcinoma of the rectum following previous surgery without pre- or post- operative radiotherapy. Between March 1973 and November 1991, 211 patients with loco-regional recurrence of rectum cancer were treated with external beam radiation treatment. Radical surgery was the only initial treatment modality. Surgical resection of local recurrence was done in 36 patients and only 17 patients could undergo complete resection. Forty-seven patients underwent radiotherapy (RT) combined with surgery and 164 received external beam radiation treatment alone to a mean total dose of 46 Gy. Among the 151 patients whose recurrence was revealed by pain, 64 (42 %) were considered to have a symptomatic response after loco-regional treatment with radiosurgery or RT alone. The mean duration of response was 12 months. The 3-year overall survival rate was 16 %. Five prognostic factors decreased the overall survival rate in multivariate analysis: high age, sex (male), concomitant distant metastasis, no tumor resection, and low total radiation dose with external beam radiation treatment alone. The 3-year survival rate for patients with completely resected recurrence was 9%. External beam RT treatment can only be considered a palliative symptomatic treatment. New techniques of early detection of local recurrence and new combined modalities approaches (radiation sensitizers or intra-operative radiotherapy) with surgical resection in some favorable cases should be studied. (authors)

[en] The 40. meeting of the American society for therapeutic radiology and oncology stood from 25. to 28 October 1998 at Phoenix (Arizona). It reviewed about the tumors of the central nervous system. Brachytherapy for prostate adenocarcinomas was also discussed. Communications were given about male genitals, bladder, mammary glands cancers, lymphomas, bronchogenic tumors, rectum cancers, sarcomas; whole body irradiations were presented and discussed. (N.C.)

[en] The hypersensitivity to low doses irradiation seems to be frequent in malignant gliomas. Others in vivo studies testing apoptosis and DNA repair are in hand. These results could have an involvement in the treatment of malignant gliomas. (N.C.)

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[en] The assay of apoptosis of lymphocytes allows to predict the intrinsic radiosensitivity of individual susceptible to have an acute toxicity increased after irradiation. A prospective study is imperative. (N.C.)