Altered apoptotic profiles in irradiated patients with incrased toxicity

in Radiotherapy & Oncology (1998), 48(1), 45

hyperfractionated accelerated radiotherapy (HART) immediately followed by surgery in locally advanced rectal cancer (LARC)

in Radiotherapy & Oncology (1998), 48(Supp1), 73

Radiotherapy of choroidal metastases.

in Radiotherapy & Oncology (1998), 46(3), 263-268

Abstract Purpose: This retrospective study was undertaken to clarify the role of high energy external beam radiation therapy (EBRT) and to determine its safety and efficacy on local control and visual ... [more ▼]

Abstract Purpose: This retrospective study was undertaken to clarify the role of high energy external beam radiation therapy (EBRT) and to determine its safety and efficacy on local control and visual acuity in patients suffering from choroidal metastases (CM). Materials and methods: The records of 58 consecutive patients treated with EBRT between 1970 and 1993 were analyzed. The female to male ratio was 2.9 and the median age was 59 years (range 40–81 years). Thirty-six patients (62%) had unilateral CM and 22 patients had bilateral CM. The mean number of lesions per eye was two. Retinal detachment was present in 65% of cases. The primary tumour (PT) was breast carcinoma for 38 patients (75%), lung carcinoma for 10 patients (17%) and gastrointestinal, genitourinary or unknown PT for the remaining 10 patients. The median interval of time between the PT and the CM was 55 months (range 0–228 months). All patients were treated with megavoltage irradiation. The median prescribed dose was 35.5 Gy (range 20–53 Gy) normalized at a 2 Gy per fraction schedule with an a/b value of 10 Gy. Various techniques were used and whenever possible the lens was spared. Ten patients with unilateral disease were treated in both eyes. Results: The tumour response was slow. When assessed after 3 months or more, the complete response rate was 53% with significantly better results for doses higher than 35.5 Gy (72 versus 33%; P = 0.009). Visual acuity was improved or stabilized in 62% of patients, with also significantly better results when doses higher than 35.5 Gy (P = 0.014) were administered. Amongst 26 patients with unilateral CM who had no elective contralateral irradiation, three developed metastasis in the opposite eye versus none of the 10 patients who had bilateral irradiation. Five complications occurred (three cataracts, one retinopathy and one glaucoma). Conclusion: Radiation therapy is an efficient and safe palliative treatment for choroidal metastases and it helps the preservation of vision. Thus, there is a major impact on the quality of life in a group of patients with an almost uniformly fatal prognosis. Both tumour response and visual acuity are significantly improved if doses higher than 35.5 Gy are administered. Whenever possible, a lens sparing technique should be used. Ó 1998 Elsevier Science Ireland Ltd. [less ▲]

Modulation of the radiosensitizing effect of (E)-24-deoxy-(fluoromethylene)cytidine (FMdC)by thymide analogues AZT, D4T and idUrd.

in Radiotherapy & Oncology (1997), 43(supp 2), 13

Information transfer between angiographic films and CT images: a tool to delineate the target volume

in Radiotherapy & Oncology (1997), 45

Abstract Background and purpose: This work was undertaken to improve the definition of target volumes for radiosurgery using the angiographic and CT data. Materials and methods: The basis of this new ... [more ▼]

Abstract Background and purpose: This work was undertaken to improve the definition of target volumes for radiosurgery using the angiographic and CT data. Materials and methods: The basis of this new method is to combine both imaging modalities and to compare them in each representation, i.e. to plot the volume obtained by angiography on CT images and also the contours defined by the CT on angiographic films. To obtain the angiographic volume, the radiographs are taken at several incidence angles. The X-ray sources position and the position of the films are determined using rectangular markers, then the intersection of all the loci of the target volume are calculated. Results: Verifications with a phantom show the accuracy of the procedure and the benefit obtained by increasing the number of angles of incidence in the angiographic imaging. The centre of gravity of the experimental target could be localized to an accuracy of better than 0.4 mm. The method was used in 11 clinical cases with excellent clinical results. Conclusions: The method can be easily applied and improves the delineation of target volumes in radiosurgery. CT data counterbalances the relative weakness of angiography concerning the three-dimensional geometry. Angiography adds useful information on the blood flow that is not shown in CT. Almost all the presented clinical cases benefit from the technique described here. [less ▲]

What about lorisk Figo Stage Ia and Ib, G1-G2 endometrial adenocarcinoma ?

in Radiotherapy & Oncology (1996), 43(Supp 1), 6

Hypofractionation in retinoblastoma: an increased risk of retinopathy.

in Radiotherapy & Oncology (1993), 28(2), 157-161

Hypofractionation in retinoblastoma: an increased risk of retinopathy.

in Radiotherapy & Oncology (1993), 28

Forty-four eyes in 38 children were treated between 1963 and 1991 by external radiotherapy for retinoblastoma. Treatment modalities varied widely during this period; in addition to radiotherapy there was ... [more ▼]

Forty-four eyes in 38 children were treated between 1963 and 1991 by external radiotherapy for retinoblastoma. Treatment modalities varied widely during this period; in addition to radiotherapy there was chemotherapy (16/44), photocoagulation (14/44), and laser therapy or cryotherapy (14/44). Treatment technique and dose fractionation also varied widely; lateral beam technique (39/44) versus anterior or anterior/lateral beam; doses per fraction ranged from 1 to 4.5 Gy, total doses from 30 to 61.5 Gy, and overall times from 22 to 49 days. Patients were followed at 3-month intervals, and actuarial survival at 10 years was 88%, with 62% local control. Ten eyes showed clinical evidence of retinopathy. A multivariate analysis of factors associated with increased risk of retinopathy was carried out using the Cox proportional hazards model and the mixture model of Farewell. The estimated latent time was 17 months (95% confidence interval, 14-20 months). The only factors found to be significantly associated with retinopathy were total dose multiplied by dose per fraction, or total dose normalized to the equivalent total dose in 2-Gy fractions as estimated from the LQ model, and these gave equivalent descriptions. There were trends (not significant) for increased risk of retinopathy when treatments included chemotherapy or photocoagulation, and for decreased risk (also not significant) when cryotherapy was used in conjunction with radiotherapy. No significance could be attached to any of the following: number of sites per eye, Reese-Ellsworth stage, and family history. We conclude that hypofractionation carries a significant risk for retinopathy in the treatment of retinoblastoma. [less ▲]

A linear-quadratic model of cell survival considering both sublethal and potentially lethal radiation damage

in Radiotherapy & Oncology (1991), 21(4), 273-276

We assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was ... [more ▼]

We assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was enhanced increased exponentially with a linear and a quadratic component, namely xi and psi: RR = e xi D + psi D2. Survival of irradiated cells can thus be expressed by a combined linear-quadratic model considering four variable, namely alpha and beta for the capacity of the cells to accumulate sublethal damage, and xi and psi for their capacity to repair potentially lethal damage: SF = e(xi - alpha)D + (psi - beta)D2. [less ▲]