Biomedical subjects

C Berns

Publications and source records attributed to C Berns.

8 recordsLinked to original sources

PubMed2005

Daytime pulsed dose rate brachytherapy as a new treatment option for previously irradiated patients with recurrent oesophageal cancer.

The aim of this study was to evaluate the feasibility, effects, and toxicity of pulsed dose rate (PDR) brachytherapy for re-irradiation of oesophageal carcinoma. A total of 16 patients (median age 67 years) with inoperable recurrences from oesophageal cancer after primary radio-(chemo)-therapy (median 50 Gy) were re-irradiated using PDR brachytherapy ((192)Ir, 37 GBq). Treatment was carried out on an outpatient basis applying a weekly 5 Gy daytime schedule (0.5 Gy pulse(-1) h(-1), total dose 15-20 Gy). The dose was prescribed 10 mm from the mid-dwell position and encompassed the clipped tumour extension with 2 cm margins. The use of clips for delineation of tumour extent and catheter movement during irradiations was evaluated. All 61 PDR treatments were applied safely. The median catheter movement was 5 mm, range 2-12 mm. After a median follow-up of 8 months, three patients had a complete and five a partial remission. Body weight increased in 5 of 16 (31%) and was stable in 4 of 16 (25%) patients, respectively. The median grade 2 (RTOG/EORTC) dysphagia-free survival was 17 months. Seven patients experienced grade 1, five grade 2, and one grade 3 late toxicity. Three patients with uncontrolled locoregional disease showed grade 4 complications (oesophago-tracheal fistulae (n=2), fatal arterial bleeding (n=1). Daytime PDR brachytherapy proved to be feasible and provided effective palliation. Toxicity remains a major problem. Thus, total dose should be restricted to <15 Gy in this palliative situation.

Aged↗

PubMed2004

[Reirradiation of chest wall local recurrences from breast cancer].

OBJECTIVE: The aim of this article was to describe the radio-therapeutic treatment options in previously irradiated patients suffering from breast cancer local recurrences and to review the literature. MATERIAL AND METHODS: Reirradiation of the chest wall can be performed using electron beams or alternatively CLDR/PDR (continuous/pulsed low dose rate) brachytherapy techniques with large skin moulds. With both techniques high doses can be applied to the chest wall while deeper-seated organs (lung, heart) can be spared to a large extent. Electron-beam therapy is readily available and the depth of treatment can be easily controlled by selecting the appropriate energy. The protracted irradiation schedule of CLDR/PDR brachytherapy results due to radiobiological reasons in a broad therapeutic ratio and safe treatment time. RESULTS: In the literature, more than 250 cases being reirradiated for chest wall local recurrences have been published. After retreatment using electron beams complete remissions were obtained in 41-74 % of the patients (brachytherapy 79-82 %). Severe grade IV complications (RTOG/EORTC) occurred in less than 10 % of the patients. CONCLUSIONS: With regard to the limited treatment options reirradiation of chest wall local recurrences resulted in high local control rates while toxicity remained acceptable. These data weaken the radio-therapeutic dogma that reirradiation of the chest wall may not be possible.

Brachytherapy↗

PubMed2001

Results of chest wall reirradiation using pulsed-dose-rate (PDR) brachytherapy molds for breast cancer local recurrences.

PURPOSE: We report in a retrospective study on the effect and toxicity of chest wall reirradiation using pulsed-dose-rate (PDR) afterloading molds. METHODS AND MATERIALS: Between 1993 and 1999, a total of 58 patients were treated. All patients presented with locally recurrent breast cancer (31 patients had concomitant distant metastases) after mastectomy and a previously completed course of radiation therapy (median, 54 Gy; range, 36-70). Indication for reirradiation was a progressive macroscopic skin recurrence in 30 cases and an incomplete surgical resection in 28 patients. Standard treatment consisted of a split course with two fractions of 20 Gy (interval, 31 days). The reference dose was prescribed to the skin surface at 5 mm distance from the source. PDR brachytherapy (37 GBq, (192)Ir) was carried out after geometric distance optimization with 0.5-1 Gy/pulse/h. The irradiated median area was 423 cm(2) (range, 100-919). The median follow-up was 18 months (range, 7-84). RESULTS: The actuarial 1-, 2- and 3-year local recurrence-free survival rates in patients treated for macroscopic disease (microscopic disease in parenthesis) were 89% (96%), 81% (85%), and 75% (71%). Local control was obtained in 24/30 (22/28) patients. Twenty-nine of the 34 patients (85%) who deceased during follow-up were locally controlled. 9/58 patients experienced Grade III acute toxicity, 35/58 patients Grade III (29/58 telangiectasia, 6/58 contracture), and 4/58 Grade IV late toxicity (RTOG/EORTC). CONCLUSION: Reirradiation of the chest wall using PDR brachytherapy molds is effective and provides a high local control rate with acceptable toxicity.

Adult↗

PubMed2000

Long-term results of pulsed irradiation of skin metastases from breast cancer. Effectiveness and sequelae.

PURPOSE: The concept of pulsed brachytherapy suggested by Brenner and Hall requires an unusual fractionation scheme. Effectiveness and sequelae of this new irradiation method were observed in patients with disseminated cutaneous metastases of breast cancer. PATIENTS AND METHODS: A flexible, reusable skin mold (weight 110 g) was developed for use with a pulsed dose rate (PDR) afterloader. An array of 18 parallel catheters (2 mm diameter) at equal distances of 10 or 12 mm was constructed by fixation of the catheters in a plastic wire mesh. The array is sewn between 2 foam rubber slabs of 5 mm thickness to provide a defined constant distance to the skin. Irradiations are possible up to a maximum field size of 20 x 23.5 cm using a nominal 37 GBq Ir-192 source. Pulses of 1 Gy reference dose at the skin surface are applied at a rate of 1 pulse every 1.2 hours (0.8 Gy per hour). The dose distribution is geometrically optimized to provide a homogeneous skin dose (100% +/- 10%). The 80% dose level lies at 5 mm below the skin surface. Between April 1994 and December 1997, 52 patients suffering from cutaneous metastases at the thoracic wall were treated with 54 fields and total doses of 38 to 50 Gy (median 42 Gy) applying 2 PDR courses with a pause of 4 to 5 weeks. RESULTS: Forty-six patients (48 fields) were eligible for evaluation in June 1998. The median follow-up was 16 months (range 7.1 to 46.2 months). Local control was achieved in 40 out of 48 fields (83%) or 41 of 46 patients (89%), respectively. Moist desquamation occurred in 52% of the patients. Late reactions were judged after a minimum follow-up of 6 months. Thirty-two fields had been previously irradiated with external beam therapy to doses of 40 to 60 Gy. Regardless of whether the skin was preirradiated or not all patients surviving long enough developed telangiectasia within 2 years after PDR irradiation. In preirradiated patients (n = 32) skin contractures and/or skin necrosis occurred in 12% each. In newly irradiated patients (n = 14) no contractures or skin necrosis were observed. CONCLUSIONS: Pulsed brachytherapy is an effective and time-sparing method for the treatment of cutaneous metastases from breast cancer. Skin reactions are comparable to the sequelae of orthovoltage therapy. Two sessions of approximately 20 Gy PDR were tolerated on preirradiated skin without severe sequelae.

Brachytherapy↗

PubMed1997

Consequences of optimization in PDR brachytherapy--is a routine geometrical optimization recommendable?

PURPOSE: On the basis of clinical examples for interstitial volume implants and surface molds the benefit and disadvantage of optimization in pulsed dose rate (PDR) brachytherapy using a stepping source was investigated. Geometrically optimized PDR dose distributions were compared with nonoptimized ones as produced by Ir wires. METHODS AND MATERIALS: In 25 patients who were treated with a double-plane interstitial breast implant with flexible catheters the first smoothly surrounding isodose, the reference volume and the uniformity and quality index derived from natural dose-volume histograms (Anderson) were considered. The effect of geometrical optimization on surface molds, which were used to irradiate chest wall relapses from breast cancer, was investigated by analyzing the reference surface, dose profiles, and depth-dose curves of a source arrangement covering an area of 10 x 10 cm2. RESULTS: Only in 3 of 25 patients the dose distribution of the volume implant was worsened by geometrical volume optimization regarding the homogeneity or the first smoothly surrounding isodose. Predominantly geometrical volume optimization reduced underdosage at the edges of the implants and improved the dose uniformity. The reference volume was increased. The geometrical distance optimization of surface mold dose distributions resulted in an enhancement of the reference surface and an improvement of the dose homogeneity on the skin surface. CONCLUSIONS: Geometrical optimization substantially changes the dose distribution. Only in a minority of cases the dose distributions of volume implants were worsened by geometrical volume optimization. Nevertheless, a close look at the results has to be recommended, especially if an overdosage in the lateral regions of the dose distribution and a dose falloff near the middle catheters is observed. The enhancement of the reference volume by geometrical volume optimization must be considered when choosing the active lengths. In surface mold treatment planning geometrical distance optimization is necessary to achieve homogeneous dose distributions for irradiation fields of different size and shape.

Brachytherapy↗

PubMed1997

PDR brachytherapy with flexible implants for interstitial boost after breast-conserving surgery and external beam radiation therapy.

BACKGROUND AND PURPOSE: For radiobiological reasons the new concept of pulsed dose rate (PDR) brachytherapy seems to be suitable to replace traditional CLDR brachytherapy with line sources. PDR brachytherapy using a stepping source seems to be particularly suitable for the interstitial boost of breast carcinoma after breast-conserving surgery and external beam irradiation since in these cases the exact adjustment of the active lengths is essential in order to prevent unwanted skin dose and consequential unfavorable cosmetic results. The purpose of this study was to assess the feasibility and morbidity of a PDR boost with flexible breast implants. MATERIALS AND METHODS: Sixty-five high risk patients were treated with an interstitial PDR boost. The criteria for an interstitial boost were positive margin or close margin, extensive intraductal component (EIC), intralymphatic extension, lobular carcinoma, T2 tumors and high nuclear grade (GIII). Dose calculation and specification were performed following the rules of the Paris system. The dose per pulse was 1 Gy. The pulse pauses were kept constant at 1 h. A geometrically optimized dose distribution was used for all patients. The treatment schedule was 50 Gy external beam to the whole breast and 20 Gy boost. PDR irradiations were carried out with a nominal 37 GBq 192-Ir source. RESULTS: The median follow-up was 30 months (minimum 12 months, maximum 54 months). Sixty percent of the patients judged their cosmetic result as excellent, 27% judged it as good, 11% judged it as fair and 2% judged it as poor. Eighty-six percent of the patients had no radiogenous skin changes in the boost area. In 11% of patients minimal punctiform telangiectasia appeared at single puncture sites. In 3% (2/65) of patients planar telangiectasia appeared on the medial side of the implant. The rate of isolated local recurrence was 1.5%. In most cases geometrical volume optimization (GVO) yields improved dose distributions with respect to homogeneity and compensation of underdosage at the margins of the implant. Only in 9% of patients was the dose distribution impaired by GVO. However, GVO causes a number of substantial changes of the dose distribution which have consequences for its application. CONCLUSIONS: The interstitial CLDR boost of the breast can be replaced by the PDR technique without severe acute and late complications and without deterioration of the cosmetic results.

Adult↗

PubMed1996

First experiences with superfractionated skin irradiations using large afterloading molds.

PURPOSE: Radiotherapy of cutaneous metastases of breast cancer requires large radiation fields and high doses. This report examines the effectiveness and sequelae of superfractionated irradiation of cutaneous metastases of breast cancer with afterloading molds on preirradiated and nonirradiated skin. METHODS AND MATERIALS: A flexible reusable skin mold was developed for use with a pulsed (PDR) afterloader. An array of 18 parallel catheters was sewn between two foam rubber slabs 5 mm in thickness to provide a defined constant distance to the skin. By selection of appropriate dwell positions, arbitrarily shaped skin areas can be irradiated up to a maximal field size of 17 x 23.5 cm2. Irradiations are performed with a nominal 37 GBq 192Ir stepping source in pulses of 1 Gy/h at the skin surface. The dose distribution is geometrically optimized. The 80 and 50% dose levels lie 5 and 27 mm below the skin surface. Sixteen patients suffering from metastases at the thoracic wall were treated with 18 fields (78-798 cm2) and total doses of 40-50 Gy applying two PDR split courses with a pause of 4-6 weeks. Eleven of the fields had been previously irradiated with external beam therapy to doses of 50-60 Gy at 7-22 months in advance. RESULTS: For preirradiated fields (n = 10) the results were as follows: follow-up 4.5-28.5 months (median 17); local control (LC): 8 of 10; acute skin reactions: Grade 2 (moist desquamation) 2 of 10; intermediate/late skin reactions after minimum follow-up of 3 months: Grade 1 (atrophy/pigmentation): 2 of 10, Grade 2-3a (minimal/marked teleangiectasia): 7 of 10, Grade 4 (ulcer): 1 of 10; recurrencies: 2 of 10. For newly irradiated fields (n = 7) results were: follow-up: 2-20 months (median 5); LC: 6 of 7; acute reactions: Grade 1: 4 of 7, Grade 2: 3 of 7; intermediate/late skin reactions after minimum follow-up of 3 months (n = 5): Grade 2-3a: 2 of 5; recurrencies: 0 of 7. Local control could be achieved in 82% of the mold fields. Geometric optimization was mandatory to achieve a homogeneous dose distribution on the skin. CONCLUSION: Superfractionated brachytherapy with skin molds is an effective alternative for the treatment of skin metastases of breast cancer even if the skin is preirradiated. This method is economically advantageous compared to external beam therapy, which would require several weeks. At the curved chest wall, optimized molds can provide better dose homogeneity than abutted electron fields. Skin reactions are comparable to the sequelae of orthovolt irradiation. In preirradiated areas, PDR doses should be restricted to 40-45 Gy. PDR doses of 50 Gy seem to be the limit for tolerance even in previously unirradiated fields.

Adult↗

PubMed1994

Combined external beam radiotherapy and intraluminal high dose rate brachytherapy on bile duct carcinomas.

PURPOSE: The aim of this study was to investigate the effectiveness and complications of combined external beam and intraluminal high dose rate irradiation and various adjuvant biliary drainage techniques on patients with bile duct carcinomas. METHODS AND MATERIALS: Eighteen patients with carcinomas of the hepatic duct bifurcation and 12 patients with carcinomas of the choledochus duct or the common hepatic duct were treated with combined external beam radiotherapy and intraluminal high-dose rate brachytherapy. Nine patients received radiotherapy after palliative tumor resection and 21 patients were primarily irradiated. Twenty-five patients completed the full course of radiotherapy. On these patients, the reference doses for the external beam varied from 30 to 45 Gy and for brachytherapy from 20 to 45 Gy. Biliary drainage after radiotherapy was achieved either with percutaneous catheters, endoprosthesis, or stents. RESULTS: The median survival for the entire group was 10 months. The actuarial survival was 34% after 1 year, 18% after 2 and 3 years, and 8% after 5 years. The subgroup with palliative tumor resection exhibit a significantly better survival (median: 12.1 months vs. 7.9 months). Three patients are still living without evidence of disease since 35 to 69 months. Major complications like bacterial cholangitis could be lowered from 37% to 28% through exchange of percutaneous transhepatic catheters to endoprosthesis or stents. The longest lasting drainages were achieved through stents. The frequency of radiogenic ulcera were lowered from 23% to presently 7.6% after the total dose of the high dose rate afterloading boost was reduced to 20 Gy. CONCLUSIONS: The present standard treatment schedule 40 Gy for the external beam and 20 Gy (fourfold 5 Gy) for the afterloading boost seems to be appropriate and well tolerated. After radiotherapy, a permanent supply of drainage should be made with a stent.

Adenocarcinoma↗