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A Hackl

Publications and source records attributed to A Hackl.

At least 19 recordsLinked to original sources
PubMed1999

Consolidation radiotherapy after carboplatin-based chemotherapy in radically operated advanced ovarian cancer.

OBJECTIVE: The aim of the study was to evaluate the effect of additional radiotherapy after chemotherapy on the relapse-free and overall survival rates of patients with advanced ovarian cancer. METHODS: Between 1985 and 1992 64 patients with radically operated ovarian cancers (4 stage IC, 2 stage II, 54 stage III, and 4 stage IV) were enrolled in a randomized study. Radical surgery comprised total abdominal hysterectomy and bilateral salpingo-oophorectomy, omentectomy, and pelvic and paraaortic lymphadenectomy. All patients received adjuvant chemotherapy with carboplatin IV 400 mg/m2, epirubicin IV 70 mg/m2 on day 1 and prednimustine orally 100 mg/m2 on days 3 to 7 at 1-month intervals. Thirty-two patients without residual disease were randomized to whole abdominal radiation (30 Gy, administered over 4 weeks). An additional 21.6 Gy were delivered to the pelvis and 12 Gy to the paraaortic region up to the diaphragm for total doses of 51.6 and 42 Gy, respectively. Cancer-related survival was calculated with the Kaplan-Meier and Cox proportional hazards methods. RESULTS: The relapse-free and overall survival rates of patients who received adjuvant chemoradiotherapy were significantly higher than those of patients who received adjuvant chemotherapy only (68% vs 56% at 2 years and 49% vs 26% at 5 years, P = 0.013, and 87% vs 61% at 2 years and 59% vs 33% at 5 years, P = 0.029). The differences were most pronounced in patients with stage III disease (77% vs 54% at 2 years and 45% vs 19% at 5 years, P = 0. 0061, and 88% vs 58% at 2 years and 59% vs 26% at 5 years, P = 0. 012). Toxicities were acceptable. CONCLUSION: Sequential combination of platinum-based chemotherapy with open-field abdominal radiotherapy is a promising adjuvant regimen for patients with advanced ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Prognostic factors in patients with carcinoma of the uterine cervix treated with external beam irradiation and IR-192 high-dose-rate brachytherapy.

PURPOSE: Prognostic factors in cancer of the cervix for patients treated with external beam irradiation (EBR) and low-dose-rate (LDR) brachytherapy have been characterized. However, despite the increasing use of high-dose-rate (HDR) intracavitary placements (ICP), few studies with adequate follow-up have analyzed prognostic factors. This study investigates pretreatment and treatment factors for their correlation with treatment outcome after EBR and HDR-ICP. METHODS AND MATERIALS: Between September 1985 and December 1994, 181 patients with carcinoma of the cervix FIGO stages IB-IV received EBR and HDR brachytherapy. Hemoglobin (Hb) levels were maintained above a level of 11 g/dl during the treatment by transfusion. Patient age ranged from 34 to 84 years (median: 66). The median follow-up time for patients at risk is 69 months (range: 23-140). Pretreatment and treatment parameters analyzed to determine their prognostic value included age, FIGO stage, tumor size, tumor type and grade, pretreatment Hb level, number of HDR-ICP, total dose from HDR-ICP, overall dose to point A, and overall treatment time. Also evaluated was the prognostic value of enlarged lymph nodes noted on pretreatment CAT scan of the abdomen and pelvis. Endpoints studied in uni- and multivariate analyses were disease-specific survival (DSS), freedom from disease (FFD), pelvic control (PC), and probability of distant metastases (DM). RESULTS: At 5 years the DSS, FFD, and PC rates for all patients were 60%, 58%, and 67%, respectively. The 5-year FFD by stage was: IB: 94%; II: 63%; IIIB: 43%; and IV: 0%. The PC rates were 94%, 66%, 59%, and 0%, respectively. In univariate analysis the prognostic factors identified for FFD were FIGO stage, tumor size, initial Hb level, and enlarged pelvic and/or paraaortic nodes (all: p < 0.0001). Age was inversely correlated with outcome (p = 0.0081). The 5-year FFD rates for tumors (< 3, > or = 3 < 6, > or = 6 cm) were 97%, 65%, and 24%; patients with initial Hb levels < or = 11g/dl had a FFD of 26% versus 69% for patients with levels > 11g/dl; and those with pelvic and/or paraaortal nodes > or = 1 cm had a survival of 32% versus 68% in patients with negative readings. The same factors were also prognostically significant for DSS, PC, and DM. Patients with persistent disease or pelvic failures had a significantly higher incidence of DM than patients in whom pelvic disease was controlled (p < 0.0001).Histological and treatment parameters including overall treatment time were not of prognostic significance for any of the endpoints studied. In multivariate analysis tumor size was the most powerful parameter for DSS, FFD, PC (p < 0.0001) and DM (p = 0.0001), followed by low initial Hb level (DSS: p = 0.0004, FFD: p = 0.0009, PC: p = 0.0012, DM: p = 0.0265), and enlarged pelvic and/or paraaortic nodes which were predictive for DSS (p = 0.0210) and DM (p = 0.0011). CONCLUSION: This study confirms that prognostic factors for patients treated with HDR brachytherapy are similar to those reported in previous series that employed LDR brachytherapy. The significance of tumor size, pretreatment Hb level, and enlarged pelvic and/or paraaortic lymph nodes on CAT scan over FIGO stage of disease were demonstrated. Future prospective trials should be undertaken to confirm the validity of these factors and to elucidate their therapeutic implications.

Adult↗
PubMed1998

[The photon therapy of subfoveal choroidal neovascularization in age-dependent macular degeneration. The results of a prospective study in 40 patients].

AIM: To determine the effect of external beam radiotherapy on subfoveal choroidal neovascularization in age-related macular degeneration. PATIENTS AND METHODS: Between September 1995 and July 1996, 40 patients (9 males and 31 females; mean age 74 years, range 61 to 83 years) were included in a prospective study. Eight patients had classic, well-defined neovascularisations, 32 patients had occult lesions. Complete ophthalmic investigations included visual acuity contrast sensitivity as well as fluorescein and indocyanine green angiographic examinations prior to treatment and 1, 3, 6, and 12 months after radiotherapy. External beam radiotherapy (8-MV photons) was delivered with a total dose of 14.4 Gy in 8 fractions of 1.8 Gy per day (Figures 1 and 2). The field size averaged 5.5 x 4.5 cm. RESULTS: No treatment related morbidity during or after treatment was obtained. After 6 months follow-up the visual acuity was improved in 2 (5%) patients and maintained at pretreatment level in 17 (42%) patients. However, 12 months post treatment a stable situation was found in 6 (15%) patients and a decrease in visual acuity in 34 (85%) patients (Table 1). The central visual fields deteriorated significantly from 16.5 decibel (dB) to 12.4 dB. The enlargement of exudates and neovascular membranes increased 5- to 7-fold. At 12 months after treatment, 3 (7.5%) patients stated that they had improved vision subjectively, 12 (30%) patients had no change and 25 (62.5%) patients suffered from subjective decrease in visual acuity. CONCLUSIONS: Using a total dose of 14.4 Gy/1.8 Gy no difference concerning visual acuity and exudative changes in comparison to the natural history on age-related macular degeneration was obtained after 12 months. However, the results of multicenter studies are to be awaited.

Aged↗
PubMed1998

The costs of radiosurgical treatment: comparison between gamma knife and linear accelerator.

Radiosurgical treatment can be carried out by means of a Gamma Knife or a Linear Accelerator. The Linear Accelerator may be either a single-purpose appliance, exclusively employed in radiosurgery, or an adapted appliance, which is used primarily for fractioned radiotherapy, and only additionally for radiosurgical purposes. The first alternative will be referred to briefly as a "dedicated Linac", the latter as an "adapted Linac". Cost accounting data for these alternatives will be discussed under three main categories: investment costs, operating costs, and finally staffing costs. Costs are only considered to the extent that this is necessary to facilitate a comprehensive cost comparison. Factors for which the costs remain the same or at least broadly the same will from the outset not be taken into consideration. These include, for instance, the costs of general or special administration, diagnosis, and image processing. The results and conclusions of this study therefore cannot be employed immediately in the evaluation of cost reimbursement schemes of the type carried out by agencies responsible for social insurance. Here, appropriate complete cost analyses especially for this purpose are required. The final comprehensive cost comparison reveals that the adapted Linac is the most favourable alternative with small annual quantities of patients. With larger numbers of patients the Gamma Knife represents the most favourable from a cost accounting angle. The dedicated Linac accordingly does not have a cost advantage for any of the examined numbers of patients. Clearly the lowest treatment costs per patient can be achieved by employing a Gamma Knife and using it to capacity.

Austria↗
PubMed1997

Carcinoma of the cervix: analysis of complications after primary external beam radiation and Ir-192 HDR brachytherapy.

BACKGROUND AND PURPOSE: There is still a concern that the use of HDR brachytherapy might result in an increase of late tissue damage. This restrospective study evaluates the incidence and severity of late complications in patients with carcinoma of the cervix who underwent combined external beam radiation (EBR) and Ir-192 HDR brachytherapy and attempts to identify pretreatment and treatment parameters correlating with late complications. MATERIAL AND METHODS: Between 1985 and 1992, 161 patients with carcinoma of the cervix (FIGO stages IB-IVB) received EBR to the pelvis (ave, max. dose 48.8 Gy) followed by 1-6 Ir-192 HDR placements (median 2). Doses to point A ranged from 8.5 to 38.7 Gy (median 17 Gy). Parameters examined included age, diabetes, obesity, history of inflammatory bowel disease or diverticulitis, prior surgery, hemoglobin level, FIGO stage, EBR dose, technique and daily dose fraction, number of HDR treatments and total dose to point A, maximum doses to bladder and rectum delivered by brachytherapy and cumulative dose to point A. Median follow-up for all patients was 37 months. Complications were rated using an in-house scoring system and according to the French-Italian Glossary (FIG). RESULTS: Actuarial 5-year survival was 93%, 57%, 46%, and 0% for stages IB, II, IIIB, and IV, respectively. Of 161 patients, 11% developed moderate and 3.7% severe sequelae (FIG: 2.5%, 3.7%). Since some patients experienced more than one complication, the overall incidence was 13.6% and 4.9% (FIG: 3.1%, 4.9%) with respective 5-year actuarial rates of 14% and 5% for moderate, and 2% and 8% for severe bowel and genitourinary tract complications (FIG: 3.5%, 0, and 2%, 8%). All severe bowel complications occurred within 1.5 years whereas urinary tract sequelae continued to develop throughout the follow-up period. FIGO stage was associated with a significant increase in late sequelae (P = 0.015). Analysis of the remaining pretreatment and treatment parameters failed to reveal any statistically significant correlation with moderate or severe sequelae. CONCLUSION: In our series using HDR brachytherapy, complication and survival rates were comparable with other series employing either LDR or HDR procedures. Of all parameters analysed, stage of disease was the only parameter significantly correlated with complications in univariate and multivariate analysis.

Brachytherapy↗
PubMed1997

Endocavitary Ir-192 radiation and laser treatment for palliation of obstructive rectal cancer.

Endoscopic laser therapy (ELT) either alone or combined with endocavitary Ir-192 radiation is performed for advanced, inoperable rectal cancer and when patients are ineligible for surgery due to severe concomitant medical illness. During the period from January 1984 to January 1997 we treated 81 patients (51 males, 30 females). Sixty-seven patients had ELT only using a ND-Yag Laser system. Twenty-five patients (average age: 80.5 years) were ineligible for surgery (Group I). Forty-two patients (74.1 years) had an advanced locally inoperable tumour (Group II). Fourteen patients (76.5 years) underwent a combined therapeutic regime with endocavitary Ir-192 afterloading following ELT (Group III). Adequate desobliteration was achieved in 100% (groups I and III) and 97% (group II) of the patients. The average interval to aftertreatment was 8.4 weeks in group I and 9.4 weeks in group II, compared to 11.5 weeks in group III. Serious complications (perianal abscess, rectovaginal fistula) occurred in 3.7%, minor complications (laser-induced bleedings, unclear fever) in 12.3%. All laser-induced bleedings could be dealt with using laser therapy. The frequency of treatment was governed by tumour mass and the patient's survival. The results suggest that additional endocavitary radiation significantly prolongs the maintenance of normal bowel function compared with laser therapy alone.

Aged↗
PubMed1997

Postoperative radiotherapy in radically resected non-small cell lung cancer.

PURPOSE: To evaluate the value of adjuvant postoperative external-beam radiation (EBR) in patients with radically resected non-small cell lung cancer (NSCLC) pT1-3 pN0-2 compared to patients with resected NSCLC without adjuvant EBR. MATERIALS AND METHODS: In 155 patients (121 male, 34 female; mean age, 59 years) 105 lobectomies, 12 bilobectomies, and 38 pneumonectomies with radical lymph node dissection of the contralateral [corrected] side were performed. Postoperative staging was done according to the TNM system and was as follows: pT1 (n=38), pT2 (n=89), pT3 (n=28); pN0 (n=39), pN1 (n=67) and pN2 (n=49). Histopathologic study revealed 68 squamous cell carcinomas, 53 adenocarcinomas, 21 large cell carcinomas, 6 adenosquamous cell carcinomas, and 7 bronchioloalveolar cell carcinomas. All patients were randomly assigned into two treatment groups: 72 patients with no further treatment (control group), and 83 patients (EBR group) with adjuvant postoperative EBR of the bronchial stump and mediastinum (50 to 56 Gy, 8 or 23 MV photons, 2 Gy/d, 5 d/wk) beginning 4 to 6 weeks after surgery. RESULTS: The overall 5-year survival rate (median observation time, 43 months) of all patients was 24.1% (EBR group, 29.7%; control group, 20.4%; p>0.05, not significant). The relative risk of the EBR group was 0.85 with a two-sided confidence interval of 0.66 to 1.09. The overall 5-year recurrence-free survival was 20.6% (EBR, 27.1%; control group, 15.6%; p=0.07). The relative risk of the EBR group was 0.80 with a confidence interval of 0.63 to 1.01. The rate of local recurrences at the bronchial stump and/or mediastinum was significantly smaller in the EBR group (n=5) than in the control group (n=17) (p<0.01). Multivariate analysis (chi2 test) demonstrated an independent influence of postoperative EBR on the incidence of local recurrences. The incidence of distant metastases was slightly but not significantly higher in patients without EBR (38 patients) compared to those who had EBR (32 patients). CONCLUSION: High-dose postoperative EBR to the mediastinum significantly reduces the risk of local recurrence at the bronchial stump and/or mediastinum. Age, sex, histologic subtype, tumor size, surgical approach, or extent of lymph node involvement had no prognostic value--only postoperative EBR had an independent influence on the risk of local recurrence. The effect of postoperative EBR was on the verge of significance with respect to recurrence-free survival and showed the same tendency in overall survival, however with an attenuated relative risk.

Adenocarcinoma↗
PubMed1996

"Adjuvant" external radiation of the mediastinum in radically resected non-small cell lung cancer.

OBJECTIVE: The effect of postoperative external beam radiation in MO non-small cell lung cancer resected with curative intention was evaluated in a randomized trial. METHODS: In 155 patients (121 males, 34 females; mean age: 59 years) 105 lobectomies, 12 bilobectomies and 38 pneumonectomies with radical lymph node dissection to the contralateral side were carried out. Histology revealed squamous cell (n = 68), adeno- (n = 53), large cell (n = 21), adenosquamous (n = 6) or bronchioloalveolar type (n = 7) carcinomas. The pathologic stages T1 (n = 38), T2 (n = 89), T3 (n = 28); NO (n = 39), N1 (n = 67), and N2 (n = 49) were evenly distributed between the two treatment groups: group A (72 patients) had no further oncologic treatment, while group B (83 patients) had external beam radiation to the mediastinum (50-56 Gy, 8 or 23 MeV photons, 2 Gy/day, 5 days a week) beginning 4 weeks after the operation. RESULTS: The overall 5-year survival rate of the whole collective was 24.1% without any significant difference between the radiotherapy group B (29.7%) and the control group A (20.4%) (log-rank test: P > 0.05). The overall 5-year recurrence-free survival rate was 20.1%, with no difference between groups B and A (radiotherapy: 22.7, controls: 15.6%, long-rank test: P > 0.05). There was no difference in the incidence of distant metastases (external beam radiation: n = 32; controls: n = 38). The rate of local recurrences at the bronchial stump or in the mediastinum, however, was significantly reduced in the radiotherapy group (n = 5) compared with 17 in the controls (P < 0.01 chi-square test). A multivariate analysis confirmed the independent influence of postoperative radiotherapy on the incidence of local recurrence. CONCLUSIONS: External radiation of the mediastinum in radically resected non-small cell lung cancer reduces the risk of local recurrence, but has no influence on distant metastastic spread and overall survival.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1994

Evaluating intraoperative radiation therapy (IORT) and external beam radiation therapy (EBRT) in non-small cell lung cancer (NSCLC). Five years experience.

A pilot study on intraoperative radiation therapy (IORT) combined with external beam radiation therapy (EBRT) in nonresectable non-small cell lung cancer (NSCLC) was performed in 31 patients (mean age: 66.2 years, range: 51-80; 10 anatomically and functionally, 21 functionally, nonresectable; 20 squamous-cell, 11 adenocarcinoma). The tumor was exposed by lateral thoracotomy and a staging lymph node dissection was performed (final staging 7 T1, 16 T2, 8 T3; 11 nodal positive). Ten to 20 Gy IORT (energy: 7-20 MeV electrons) were delivered to the tumor. Unilateral continuous positive airway pressure ventilation of the diseased lung was used to reduce the amount of healthy lung tissue in the IORT port and to minimize the ventilatory movement. Secondary collimation and direct shielding of radio-sensitive structures within the IORT port by aluminium sheets were used to further reduce collateral damage. Four weeks after IORT, 46 Gy EBRT (2 Gy/day 5 times a week; 8-23 MeV photons) were administered to the mediastinum and to the tumor-bearing area on an outpatient basis. In nodal positive cases the mediastinal dose was increased to 56 Gy. Twenty-three patients were evaluable. In 13 complete, in 8 partial (50-97% regression) and in 2 minor response has been achieved. Five patients experienced a recurrence (local only: 2; local and distant: 1; distant only: 2). Twelve patients died of underlying cardio-respiratory disorders within 6 to 25 months after IORT; 7 died of cancer. The overall 5-year survival rate including the incidental deaths is 14.7%. The recurrence-free survival rate is 53.2%.

Adenocarcinoma↗
PubMed1993

Iridium-192 high dose rate brachytherapy combined with external beam irradiation in non-resectable oesophageal cancer.

Forty-eight patients with non-resectable cancer of the oesophagus and oesophagogastric junction (group A: Stage I/II: n = 32; group B: Stage III/IV: n = 16) underwent intralumenal iridium-192 high dose-rate afterloading brachytherapy (5-7 Gy/session, total dose 5-21 Gy, mean 12.4 Gy) and external beam irradiation (Karnofsky > or = 80%: 50-60 Gy/2 Gy per day; Karnofsky 60%-79%: 30 Gy/3 per day). Prolonged satisfactory palliation (intake of at least semi-solid food) was demonstrated in 96% of patients. The mean survival for group A was 19.1 months and that for group B 6.9 months, with a 12-month survival rate of 66% for group A and 0% for group B (P < 0.001). Local tumour response and complication rate were significantly dose related with a predicted response rate of 70.5% and a complication rate of 50% at extrapolated response dose (ERD) 129.3 GY3 (Gy at alpha/beta = 3).

Adult↗
PubMed1992

Reduction of the dose to the lens in prophylactic cranial irradiation: a comparison of three different treatment techniques and two different beam qualities.

Three treatment techniques using two beam qualities have been compared on the basis of dose to the lens in prophylactic cranial irradiation. The dose to the lens and the globe was measured with thermoluminescent crystals in an anthropomorphic phantom and calculated by a computer-assisted planning system. A comparison was made of large field and small field techniques using 60Co and 8 MV photons. Modifications to the basic techniques studied included angulation of the gantry, angulation of the couch, and placement of an additional eye block close to the surface. The dose to the lens could be reduced to four percent of the midplane dose by applying the small-field technique combined with the use of 8 MV energy photons, by placing an additional block close to the surface, and by five degree occipitally angling the gantry, as well as rotating the treatment couch to account for the divergence of the beam. The use of 60Co produced an underdosage of the posterior segment of the globe in angled treatment techniques.

Cataract↗
PubMed1992

[Metallic mesh endoprosthesis and intraluminal high dose rate 192Ir brachytherapy in the palliative treatment of malignant bile duct obstruction. Initial results].

Since December 1989, 9 patients with inoperable malignant biliary tract obstruction were treated palliatively by a combined modality treatment consisting of placement of a permanent biliary endoprosthesis followed by intraluminal high dose-rate 192Ir brachytherapy. A dose of 10 Gy was delivered in a hyperfractionated schedule at the point of reference in a distance of 7.5 mm of centre of the source. External small field radiotherapy (50.4 Gy, 1.8 Gy per day, 5 fractions per week) was also given in six cases (M/O, Karnofsky greater than 60%). In 9/9 cases an unrestrained bile flow and an interruption of pruritus was achieved, in 78% (7/9) of cases the duration of palliation was as long as the survival time (median survival time 7.5 months).

Adenocarcinoma↗
PubMed1992

Surgical and non-surgical treatment of cancer of the oesophagus and the oesophagogastric junction: results of 200 consecutive cases.

200 consecutive, unselected patients with cancer of the oesophagus or the oesophagogastric junction (89 squamous, 110 adenocarcinoma or undifferentiated, 1 oat cell) between 1984 and 1987 were reviewed. Resection with postoperative adjuvant irradiation in the cases of squamous cell cancer, was carried out in 51 patients and non-surgical treatment [57 combined dilation and Nd-YAG-laser, 64 iridium 192 high-dose rate brachytherapy with or without 60 Gy external beam irradiation (EBR); 28 endoprostheses] was performed in the remaining 149 patients. The overall 5 year-survival rate was 9.2% (resections: 17.9%, non-resected: 5.2%). Resected nodal negative T1 or T2 patients had the best prognosis (45.8% 5-year survival). The median survival following dilation and laser was 3.4 months for all T-stages. Endoprostheses yielded a median survival of 1.7 months. Intracavitary brachytherapy gave the best palliative result with 6.5 months median survival, whereby only T1 and T2 patients benefitted from additional EBR. Histological subtype, age, sex or tumour localization did not influence survival. Multivariate analysis showed that in M0 patients the choice of treatment had a significant impact on prognosis.

Adenocarcinoma↗
PubMed1991

[Magnetic resonance tomographic screening studies of the bone marrow with gradient echo sequences: (I) the contrast relations of phase-identical and phase-shifted gradient echo sequences. Studies on probands and pathological-anatomical preparations].

Anatomical specimens and normal persons were studied by gradient echo MR imaging to determine the influence of different echo times (TE) on bone marrow contrast. First of all, six normal persons were studied to determine specific echo times for in-phase and opposed-phase states. Using different sequences bone marrow contrast in isolated femoral bones was determined and compared to results of pathological exams. Red bone marrow had no signal on opposed-phase images; contrast between red and yellow marrow was higher on opposed-phase than on in-phase images. Bone marrow lesions can be expected to be visualised with high signal on opposed-phase images; this technique should be especially suited for MR imaging of bone marrow.

Adult↗
PubMed1991

Consolidation radiotherapy following carboplatin-based chemotherapy in radically operated advanced ovarian cancer. A pilot study.

Adjuvant chemoradiotherapy was administered to 26 patients with stage Ic-IV ovarian cancer after radical cytoreductive surgery. All patients received six cycles of carboplatin, epirubicin, and prednimustine and had no evidence of disease after completion of chemotherapy. They received whole-abdominal radiation and radiation to the retroperitoneal lymph nodes. Five (23%) of the patients were discontinued on this protocol because of myelosuppression, progressive disease, or withdrawal. One patient had a small bowel obstruction due to intraperitoneal adhesions. The survival of 10 Stage III ovarian cancer patients who received chemoradiotherapy and were evaluable for assessment of treatment efficacy was retrospectively compared with the survival of 11 Stage III patients who received chemotherapy only. At 36 months, a slight advantage of the chemoradiotherapy versus the chemotherapy-only group was observed (p = 0.11). These preliminary results suggest that adjuvant chemoradiotherapy may prolong the "no evidence of disease" interval of radically operated ovarian cancer patients. Toxicity is acceptable when second-look surgery is avoided and when subsequent radiotherapy is limited to patients with no clinical evidence of disease.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Bladder and rectal dose of gynecologic high-dose-rate implants: comparison of orthogonal radiographic measurements with in vivo and CT-assisted measurements.

Bladder and rectal doses were retrospectively reviewed in 281 patients who underwent implantation of 575 gynecologic iridium-192 high-dose-rate devices. Dose measurements obtained with orthogonal radiography, in vivo thermoluminescent dosimetry, and computed tomography (CT)-assisted planning were compared. Measurements of bladder dose derived from radiographs revealed a significant difference between bladder neck dose and bladder base dose (P less than .0001). In 17% of cases, the dose to the bladder base was at least double the dose to the bladder neck. The mean dose to the rectum calculated from radiographs was 85.9% (cervix) and 90.2% (vaginal vault) of the prescribed fraction dose. The correlation coefficient factor between doses determined with orthogonal radiographs and doses determined with in vivo measurements was .9694. The dose to the bladder neck and to four rectal points determined with corresponding CT images revealed a deviation of 4% and 7%, respectively. However, calculations at the rectal wall cephalic to the specified rectal points showed higher doses to the rectum, with a ratio of 1-1.6. CT-assisted calculations at the bladder base also revealed doses that were higher than those obtained with radiographs alone by a ratio of 1.4-2.2. CT-assisted dosimetry is the method of choice.

Brachytherapy↗
PubMed1991

[Evaluation of irradiation techniques in breast carcinoma using dose-volume histograms. Comparison of the heart and lung exposure].

For irradiation of the internal mammary lymph nodes (IMN), together with irradiation of the breast the commonly used treatment techniques are of three types: 1. two tangential opposed fields, 2. three field plans with a separate "straight on" IMN-field, or 3. with a separate "angled" IMN-field. To determine lung and heart volumes and doses for these techniques, dose-volume-histograms in 30 patients were analyzed. The optimum dose distribution was achieved with the "angled" field technique and an appropriate combination of electrons and 60Co gamma radiation for the IMN-field. (The beam mixture used was 40% 60Co beam and 60% electron beam.) The least possible dose to the lung was obtained with the "straight-on" field technique and the least possible dose to the heart with the separate "angled" IMN-field technique.

Breast Neoplasms↗