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At least 19 recordsLinked to original sources
PubMed1990

Effect of endobronchial radiation therapy on malignant bronchial obstruction.

We evaluated the effect of endobronchial radiation therapy in 52 patients with malignant airway occlusion. Fifty-five endobronchial applications of the radioisotope iridium 192 were carried out. Response was assessed by change in performance status, symptom resolution, duration of symptom relief, roentgenographic reaeration, pulmonary function tests, and postimplant bronchoscopy. Thirty-three patients showed at least a one-level improvement in performance status. Of a total of 166 symptoms present prior to therapy, 131 resolved or improved. Approximately 70 percent of a patient's lifetime was rendered symptom improved or symptom free. A roentgenographic reaeration response of 30/41 (73 percent) was achieved. The average FEV1 and FVC improved from 1.5 to 2.1 L and from 2.3 to 2.9 L, respectively. Posttherapy bronchoscopy was performed between one and two months following the implant in 15 patients who agreed to undergo the procedure. Eleven (73 percent) of 15 had complete tumor regression. Major long-term complications were noted in seven patients. Endobronchial radiation, therefore, appears to be a safe and effective technique to palliate malignant airway occlusion.

Aged↗
PubMed1989

Acute radiodermatitis from occupational exposure to iridium 192.

Industrial radiography using the man-made radioisotope iridium 129 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.

Acute Disease↗
PubMed1999

Radiation retinopathy following plaque radiotherapy for posterior uveal melanoma.

OBJECTIVE: To identify the risk factors that lead to the development of radiation retinopathy following plaque radiotherapy for posterior uveal melanoma. Radiation retinopathy is a slowly progressive, occlusive vasculopathy characterized by radiation-induced endothelial damage. METHODS: Review of the medical records of patients with posterior uveal melanoma treated with plaque radiotherapy. RESULTS: Of 1300 patients with posterior uveal melanoma treated with plaque radiotherapy from July 1, 1976, through June 30, 1992, radiation retinopathy developed in 560 (43.1%). By using Kaplan-Meier survival estimates, we found that 5% of the patients had nonproliferative radiation retinopathy at 1 year (95% confidence interval [CI], 3%-6%) and 42% at 5 years (95% CI, 38%-45%). The proportion of patients with proliferative retinopathy was 1% at 1 year (95% CI, 0.2%-1.5%) and 8% at 5 years (95% CI, 5%-10%). Multivariate analyses showed that the subset of clinical variables best related to the development of nonproliferative radiation retinopathy were tumor margin of less than 4 mm from foveola (P<.001), tumor limited to the choroid (P = .002), and radiation dose rate of greater than 260 cGy/h to the tumor base (P = .02). The best subset of independent variables related to the development of radiation maculopathy were tumor of less than 4 mm to foveola (P<.001) and the use of radioisotope iridium 192 (192Ir) (P = .02) compared with iodine 125 (125I). From a multivariate model, the most important factors for the development of proliferative radiation retinopathy included diabetes mellitus (P = .01), radioisotope 192Ir (P = .01) compared with 125I, and tumor base of greater than 10 mm (P = .02). CONCLUSIONS: Radiation retinopathy is a common finding after plaque radiotherapy for choroidal melanoma, occurring in 42% of patients at 5 years. The main predictors of radiation retinopathy are posterior tumor location with margin near the foveola and high radiation dose rate to the tumor base.

Adult↗
PubMed2000

Plaque radiotherapy for uveal melanoma: long-term visual outcome in 1106 consecutive patients.

OBJECTIVE: To identify clinical predictive factors for visual outcome in a large series of patients who underwent plaque radiotherapy for uveal melanoma. DESIGN: Clinical factors, including patient data, tumor features, and radiation variables, were analyzed for their impact on visual acuity using Cox proportional hazards regression models. PARTICIPANTS: Patients with uveal melanoma and initial visual acuity of 20/100 or better in the affected eye who were treated with plaque radiotherapy between July 1976 and June 1992. MAIN OUTCOME MEASURES: Two end points were used to evaluate posttreatment visual acuity: (1) final visual acuity (good [20/20-20/100] vs poor [20/200 to no light perception]) and (2) loss of visual acuity (minimal [<5 lines Snellen visual acuity] vs moderate [> or = 5 lines Snellen visual acuity]). RESULTS: Of 1300 consecutive patients with uveal melanoma treated by plaque radiotherapy, 1106 had a visual acuity of 20/100 or better at the time of treatment. In this group, poor visual acuity was found in 34% at 5 years and 68% at 10 years of follow-up. From multivariable analysis, clinical factors that best predicted poor visual acuity were increasing tumor thickness, proximity to foveola of less than 5 mm, notched plaque shape, tumor recurrence, patient age 60 years or older, subretinal fluid, cobalt isotope, anterior tumor margin posterior to equator, and worse initial visual acuity. Moderate loss of visual acuity of 5 Snellen lines or more was found in 33% at 5 years and 69% at 10 years of follow-up. From multivariable analysis, clinical factors that best predicted moderate visual acuity loss included increasing tumor thickness, worse initial visual acuity, notched plaque shape, tumor recurrence, proximity to foveola of less than 5 mm, patient age of 60 years or older, subretinal fluid, and diabetes mellitus or hypertension. When analyzing visual outcome with regard to tumor thickness, ultimate poor visual acuity of 20/200 or worse at 5 years was found in 24% with a small melanoma (< or = 3.0 mm), 30% with a medium melanoma (3.1-8.0 mm), and 64% with a large melanoma (>8.0 mm). When analyzing visual outcome with regard to tumor proximity to visually important structures, tumors less than 5 mm from the optic disc or foveola demonstrated poor visual acuity in 35% at 5 years, whereas those 5 mm or more from the optic disc and foveola showed poor visual acuity in 25% at 5 years. CONCLUSIONS: Ultimate visual acuity after plaque radiotherapy for uveal melanoma depends on many factors, including patient age and general health, initial visual acuity, tumor location and size, subretinal fluid, radioactive isotope, and final tumor control. At 10 years' follow-up, 68% of patients demonstrate poor visual acuity. Visual acuity is most effectively preserved in eyes with small tumors outside a radius of 5 mm from the optic disc and foveola. Arch Ophthalmol. 2000;118:1219-1228

Adolescent↗
PubMed1996

Plaque radiotherapy for juxtapapillary choroidal melanoma. Visual acuity and survival outcome.

OBJECTIVES: To assess the effect of plaque radiotherapy on the visual acuity of patients with juxtapapillary choroidal melanoma and to determine the clinical predictive factors for radiation retinopathy, radiation papillopathy, local tumor recurrence, and distant metastasis. DESIGN: A retrospective review of the medical records of 93 patients with juxtapapillary choroidal melanoma who were treated initially with plaque radiotherapy. RESULTS: During a mean follow-up of 78 months, radiation retinopathy developed in 81 patients (87%) and radiation papillopathy developed in 48 patients (52%) after a mean interval of 21 and 27 months, respectively. The univariate variables that were significant predictors of radiation retinopathy were history of diabetes mellitus (P = .05) and use of a notched radioactive plaque (P = .04). The factors predictive of radiation papillopathy were age (> 45 years; P = .01), history of diabetes mellitus (P = .05), mushroom-shaped tumor configuration (P = .006), and nasal location of the tumor (P = .04). By using Kaplan-Meier survival curves, we found that the proportion of the 93 patients with radiation retinopathy was 87 (94%) at 5 years and with radiation papillopathy was 53 (57%) at 5 years. By using life-table analysis, we found that the proportion of the 93 patients who experienced a decrement of at least 3 lines of visual acuity was 67 (72%) by 50 to 60 months. Local tumor recurrence was documented in 14 patients (15%) after a mean interval of 41 months. The age of the patient (< 35 years; P = .02) and the superior (P = .004) and inferior (P = .05) locations of the tumor were predictive of local tumor recurrence. Distant metastasis developed in 11 patients (12%) after a mean interval of 44 months. The factors predictive of distant metastasis were a tumor with a basal diameter larger than 6.0 mm (P = .05), the superior location of the tumor (P = .01), and local tumor recurrence (P < .001). CONCLUSION: Based on these observations, plaque radiotherapy remains a potential option vs enucleation for the management of juxtapapillary choroidal melanoma.

Brachytherapy↗
PubMed1997

Plaque radiotherapy for the management of uveal metastasis.

BACKGROUND: Radiotherapy is effective for the management of most uveal metastases, and standard external beam radiotherapy is generally administered during a 3-to 4-week period. For those patients in whom external beam radiotherapy or other methods fail or those patients with solitary uveal metastases, plaque radiotherapy may be an alternative method. OBJECTIVE: To determine the effectiveness of plaque radiotherapy for the management of uveal metastasis. METHODS: A retrospective review of 36 patients with uveal metastases who were examined at the Oncology Service at Wills Eye Hospital, Philadelphia, Pa, and treated with plaque radiotherapy. The clinical findings and follow-up data of the primary tumor and the uveal metastasis were analyzed. RESULTS: Of the 36 patients, 27 (75%) received plaque treatment as primary therapy for the uveal metastasis and 9 (25%) received plaque treatment as secondary therapy after failure of the uveal tumor to respond to external beam radiotherapy, chemotherapy, or hormonal therapy. During treatment, 22 patients (61%) had no other systemic metastasis and 14 (39%) had controlled systemic metastasis. No patients had active metastasis elsewhere. The uveal metastasis was solitary and well circumscribed in all but 1 patient; it measured a mean of 11 mm in basal dimension and 4 mm in thickness. The mean time for treatment was 86 hours, and the mean therapeutic dose was 68.80 Gy to the tumor apex and 235.64 Gy to the tumor base. Regression of the uveal metastasis was documented in 34 patients (94%) during a mean follow-up of 11 months. As early as 3 months after treatment, the mean tumor thickness had decreased to 2 mm. Plaque radiotherapy salvaged 5 of the 6 eyes that had failed prior external beam radiotherapy. Radiation retinopathy, radiation papillopathy, or both were found in 3 patients (8%) and occurred at a mean of 8 months after treatment. At the last examination, 18 patients (50%) were alive (11 with and 7 without active systemic metastasis) and 18 (50%) were dead from systemic metastasis. CONCLUSIONS: Plaque radiotherapy is an effective method for treating selected solitary uveal metastasis. It offers a high degree of tumor control, especially for those eyes in which other methods have failed. Plaque treatment is provided during a short period, minimizing the time demand for these patients with a limited life expectancy.

Adult↗
PubMed1998

CT-simulator based brachytherapy planner: seed localization and incorporation of biological considerations.

Radiation dose prescription, interpretation, and planning can be problematic for brachytherapy due to high spatial heterogeneity, varying and various dose rates, absence of superimposed calculated isodose distributions onto affected tissues, and lack of dose volume histograms. A new treatment planner has been developed to reduce these limitations in brachytherapy planning. The PC-based planning system uses a CT-simulator to sequentially scan the patient to generate orthogonal images (to localize seed positions) and subsequently axially scan the patient. This sequential scanning procedure avoids using multiple independent patient scans, templates, external frames, or fiducial markers to register the reconstructed seed positions with patient contours. Dose is computed after assigning activity to (low dose rate) Ir192, linear Cs137, or I125 seeds or dwell times (high dose rate) to the Ir192 source. The planar isodose distribution is superimposed onto axial, coronal, or sagittal views of the tissues following image reconstruction. The treatment plan computes (1) direct and cumulative volume dose histograms for individual tissues, (2) the average, standard deviation, and coefficient of skewness of the dose distribution within individual tissues, (3) an average (over all tissue pixels) survival probability (S) and average survival dose DASD for a given radiation treatment, (4) normal tissue complication probability (NTCP) delivered to a given tissue. All four computed quantities account for dose heterogeneity. These estimates of the biological response to radiation from laboratory-based studies may help guide the evaluation of the prescribed low- or high-dose rate therapy in retrospective and prospective clinical studies at a number of treatment sites.

Brachytherapy↗
PubMed2003

The 1999 patterns of care study of radiotherapy in localized prostate carcinoma: a comprehensive survey of prostate brachytherapy in the United States.

BACKGROUND: The objective of the current study was to provide descriptive information on a representative national sample of patients with prostate carcinoma who were treated with prostate brachytherapy (PB) in calendar year 1999. METHODS: A random survey was conducted by the Patterns of Care Study in radiation oncology of 59 facilities (1 facility had no eligible patients) that treated patients with prostate carcinoma in 1999 in the United States. A weighted sample size of 36,496 patients with prostate cancer was included in the 1999 survey (unweighted sample size, 554 patients). The main measures were the clinical characteristics of men prior to treatment and the technical characteristics of PB. Patients were classified into three prognostic groups according to T stage, pretreatment prostate specific antigen (PSA) level, and Gleason score. RESULTS: A weighted sample size of 13,293 patients (36%; unweighted sample size, 162 patients) was treated with PB. Compared with a weighted sample size of 23,203 patients (64%; unweighted sample size, 392 patients) was treated with external beam radiotherapy (EB), patients who received PB were significantly younger (mean age: PB group, 67.7 years; EB group, 70.8 years; P = 0.0006). The mean pretreatment PSA level for the PB group was lower compared with the EB group (9.9 ng/mL vs. 13.33 ng/mL; P = 0.0015). The prognostic groupings were more favorable for patients in the PB group compared with patients in EB group (P = 0.0365). The utilization of androgen deprivation therapy (ADT) in the PB group was similar to the utilization of ADT in the EB group (40.4% vs. 51.3%; P = 0.2282). The vast majority of men who were treated with PB received low-dose-rate, permanent sources (89%). Fifty-four percent of men received PB monotherapy (PBM), and the remaining 46% were treated with EB in addition to PB (EBPB). The prognostic groupings were more favorable for patients in the PBM group compared with patients in the EBPB group (P = 0.0037). Of the men who were treated with low-dose-rate PB, 59% were treated with iodine-125 (I-125), and 41% were treated with palladium-103 (Pd-103). I-125 was used more frequently in men who were treated with PBM, and Pd-103 was used more frequently in men who were treated with EBPB. Postimplantation dosimetry was documented in 61.0% of men who were treated with low-dose-rate PB. Computed tomography imaging was used for 46.5% of men. CONCLUSIONS: PB was used in 36% of men who were treated with radiotherapy nationally. The mean age of men who were treated with PB was younger than the population of men who were treated with EB alone. Nearly 50% of men who received PB also received EB. EB was used more frequently in men with higher-risk disease. ADT was used in 40% of patients in the PB group. Techniques and prescription doses were consistent with published guidelines.

Adenocarcinoma↗
PubMedDate not supplied

Radiotherapy and brachytherapy for recurrent colorectal cancer.

Radical surgical excision of locoregional recurrence of colorectal carcinoma usually produces the best survival and should be attempted whenever possible. However, recurrences are often unresectable; hence palliative local therapy may be indicated. There are several options for the radiation therapy of local, unresectable, recurrent, or metastatic colorectal cancer. Whole pelvis irradiation of 4,000-5,000 cGy followed by a coned-down boost of 1,000-1,500 cGy generally provides good symptomatic palliation in 80-90% of patients, but long-term control or cure is rarely achieved. External beam irradiation of 2,000-3,000 cGy to the whole liver with or without concurrent chemotherapy may be used for palliation of metastatic disease to the liver. A combination of intraoperative radiation therapy applied directly to the tumor bed and external beam irradiation may improve local control and survival rates. Multiple options are available for the intraoperative use of brachytherapy which can deliver high radiation doses to the residual tumor, or tumor bed, sparing normal tissue.

Brachytherapy↗
PubMed2003

A semi-analytic approach to determine dose rate constant of brachytherapy sources in compliance with AAPM TG 60 formalism.

Values of dose rate constant (DRC) in compliance with AAPM TG 60 formalism recommended for intravascular brachytherapy (IVBT) were calculated for different point isotropic mono-energetic photon sources in the energy range E = 20-1000 keV using a semi-analytic model. Based on these DRC values, DRC of some existing models of 192Ir and 125I brachytherapy sources were then calculated using (1) bare energy spectra and (2) a single energy parameter which represents mean energy (photon number weighted or air-kerma weighted) for bare and actual sources or the most probable energy of the spectra (energy line with the highest probability of emission) of the investigated sources (192Ir and 125I). Applicability of the semi-analytic approach was examined by also computing the values of DRC of the investigated sources using MCNP Monte Carlo simulation code (Version 3.1) that involved modeling of the sources accurately. A comparison of values of DRC resulting from MCNP calculations with those resulting from the semi-analytic approach showed that for 192Ir sources the agreement was within 0.40% and for 125I sources it was within 2.3%.

Brachytherapy↗
PubMed1992

The influence of mineralising radionecrosis on the dose distribution in interstitial radiation therapy of brain tumours.

The influences of radionecroses arising during interstitial radiation of brain tumours with 125I, 192Ir or 198Au on dose distribution was investigated using Monte Carlo methods. The necroses have a higher density than normal tissue due to radiation-induced changes in tissue composition as well as mineral deposits. They can have a diameter of up to 1 cm around the single seeds. The higher density and changed chemical composition compared to homogeneous normal tissue leads to increased absorption of radiation around the necroses which results in a lower dose rate in the surrounding tissue. It is shown that the formation of necroses during treatment with higher energy radiation such as 192Ir (340 keV) or 198Au (400 keV) may be neglected during therapy planning as the dose rate is affected by less than 2%. If low energy radiation, e.g. 125I (28 keV) is used, the dose rate can be reduced by more than 30%. In this case the influence of the necroses on dose distribution, at least for permanent 125I implantation, may not be negligible.

Animals↗
PubMed1988

The utilization of I-125 seeds as a substitute for Ir-192 seeds in temporary interstitial implants: an overview and a description of the William Beaumont Hospital technique.

In August of 1986, the Department of Radiation Oncology at William Beaumont Hospital (WBH) initiated the routine use of high activity I-125 seeds as a substitute for Ir-192 seeds in temporary implants where the afterloading plastic tube technique was used. Through March 6, 1987, 42 temporary I-125 implants were performed as a boost for curative therapy (38 breasts, 2 sarcomas, 2 tongues). Thus far, we have observed no differences in acute toxicity. Sources ranging from 2 to 5 mCi were utilized. The advantages of I-125 are as follows: (a) Easy to shield; (b) Radiation safety; (c) Decreased exposure to sensitive organs in close proximity to the implanted site; (d) Dosimetric advantages both intrinsic and extrinsic; and (e) Any private room can be used for these patients allowing a central brachytherapy ward to be established. While the advantages were obvious, we anticipated potential disadvantages and shortcomings and these will be discussed in detail. Furthermore because of significant differences in tube and ribbon construction, the I-125 afterloading plastic tube technique has important differences from that technique used with Ir-192. These modifications must be fully understood to maintain the integrity of the I-125 seed-ribbon afterloading tube assembly. A detailed description of the technique will be emphasized.

Brachytherapy↗
PubMed1989

Treatment planning for permanent and temporary percutaneous implants with custom made templates.

Nine patients who were presented at MSKCC with primary or recurrent pelvic or head and neck tumors and for whom surgery or further external radiation were excluded, were treated with percutaneous permanent or temporary implants, with individual pre-treatment planning and custom made templates. The tumor dose distributions achieved were as good as for implants performed at the time of surgical exploration. No serious complications have been encountered.

Brachytherapy↗
PubMed1992

A comparison of radial dose functions for 103Pd, 125I, 145Sm, 241Am, 169Yb, 192Ir, and 137Cs brachytherapy sources.

Recently, encapsulated sources of 103Pd (21 keV average), 145Sm (41 keV average), 241Am (60 keV), and 169Yb (93 keV average) have been introduced as alternatives to conventional brachytherapy sources of 125I Model 6711 (27 keV average), 125I Model 6702 (28 keV average), 192Ir (369 keV average), and 137Cs (662 keV). To illustrate the dependence of the penetrating ability of photons from brachytherapy sources as a function of photon energy, a comparison of their radial dose functions is presented. Using the ITS Monte Carlo simulation code for photon-electron transport, the radial dose functions were calculated for monoenergetic photon sources with energies in the range of 30 keV to 1 MeV. Also, similar calculations were performed using the photon spectra emitted by the encapsulated brachytherapy sources. To verify the accuracy of Monte Carlo calculations, comparisons are made with our new measured data for 241Am and existing experimental and theoretical data from other investigators. A comparison of radial dose functions indicates that for 241Am, 169Yb, 192Ir and 137Cs sources radial dose functions are close to unity for distances up to 10 cm, for 145Sm the radial dose function drops to about 0.4 at 10 cm, and for 125I and 103Pd it drops precipitously to less than 0.20 at 7 cm. At 5 cm, the measured radial dose functions for 103Pd, 125I Model 6711, 125I Model 6702, 145Sm, 241Am, and 192Ir have values of 0.09, 0.34, 0.38, 0.86, 1.12, and 0.97, respectively. While all of these radioisotopes provide adequate penetrating power for interstitial brachytherapy, only the radioisotopes emitting photons with energies greater than about 40 keV can provide adequate depth dose (that is, small or no tissue attenuation) for intracavitary irradiation. Our criterion for choice of minimum photon energy suitable for intracavitary irradiation is that the radial dose function at 5 cm should not be less than 0.90. Also, note that photons with energies around 80 keV exhibit maximum penetrating ability in solid water for distances up to 5 cm.

Americium↗
PubMedDate not supplied

Computer applications to radioactive-seed: brain-tumor implants.

Malignant brain tumors, in general, and anaplastic astrocytoma and glioblastoma multiforme in particular, have been highly refractory to conventional treatments including surgery, chemotherapy and external-beam irradiation. Although better local control can be achieved with high-dose, external beam irradiation, necrosis of normal brain tissue reduces the quality of life and survival. In order to localize the radiation dose given to brain tumors, the temporary implantation of 125I and 192Ir seeds is undergoing clinical trials at several medical centers. Computers play a key role in this treatment modality: in addition to being essential for image reconstruction of CT scans, a computer is used to reconstruct a tumor volume from outlined regions on individual cuts; a programable calculator is used in conjunction with a stereotaxic head holder to obtain the coordinates of the radioactive seeds; a radiation-therapy, treatment-planning computer is used to optimize the radioactive-seed positions and strengths, and to generate the corresponding dose distribution.

Astrocytoma↗
PubMed2004

Dosimetric characterization of radioactive sources employed in prostate cancer therapy.

PURPOSE: Three types of radiation sources are employed currently in the radiation treatment of prostate cancer, namely, external, implant, and high-dose-rate (HDR) sources using an afterloader method. The present article provides a detailed dosimetric characterization of several commercially available implant sources and an HDR source employing the same stochastic code and dataset. METHODS AND MATERIALS: The radioactive implants considered are (125)I seeds: models 6701, 6702 and 6711, (103)Pd seed: model 200, and a high-dose-rate (192)Ir source: microSelectron-HDR model V7.0x. Detailed modeling of the sources and their associated X-rays and gamma rays has been carried out using the stochastic code MCNP4C. A sensitivity study has been conducted to quantify effects of varying the composition and density of the tissue equivalent material, and a dosimetric comparison is made for different media (tissue equivalent, solid-water, water, and air). Furthermore, a set of measurements using thermoluminescent dosimeters has been done to provide experimental validation of some of the calculational results obtained. RESULTS: Effectively, high-precision dosimetric values (Monte-Carlo statistical 1-sigma error <1%) are provided in tabulated form over a wide range to enable therapy planning as well as to check numerical values calculated by other methods. A subset of calculated dosimetric values has been experimentally validated by using thermoluminescent dosimeters. CONCLUSIONS: A detailed comparison of results obtained for the radial dose distribution function, anisotropy factor, and dose rate constant as defined in the TG-43 protocol has indicated reasonable agreement with the values reported in the literature.

Brachytherapy↗
PubMed2005

192Ir or 125I prostate brachytherapy as a boost to external beam radiotherapy in locally advanced prostatic cancer: a dosimetric point of view.

PURPOSE: This work aims at comparing the dosimetric possibilities of 125I or 192Ir prostate brachytherapy (Bt) as a boost to external beam radiotherapy in the treatment of locally advanced adenocarcinoma. METHODS AND MATERIALS: From 1/1997 to 12/2002, 260 patients were treated. Until 12/2001 a low dose rate (LDR) treatment with 192Ir wires was used, later replaced by a high dose rate (HDR) delivered with an 192Ir stepping source technology. For the present work, we selected 40 patients including the last 20 treated, respectively, by LDR and HDR. The planning CT Scans of all these 40 patients were transferred into the 3D Prowess system for 125I permanent implants design according to the Seattle method. The reference data for dosimetric comparisons were the V100 and the prescribed dose for 192Ir as well as the dose delivered with 125I techniques to the 192Ir V100. We compared V100-150 data as well as doses to the organs at risks (OR) and cold spots (CS). RESULTS: The V100 is 85.3+/-8% for 192Ir LDR and 96+/-2% for HDR techniques (P < 0.0001). In comparison with 125I, the 192Ir LDR mode induces higher hyperdosage volumes inside the CTV but also more CS, while maximal doses to urethra and rectum are, respectively, 17 and 39% less with 125I (P < 0.0001). In comparison with the 192Ir HDR mode, 125I Bt induces higher hyperdosage volumes and slightly more CS deliberately planned around the bladder neck. If delivered doses to urethra are identical, those to the 20% anterior part of the rectum are 33% less with 125I (P < 0,0001). The 125I Bt technique was only possible in 24 out of the 40 patients studied due to pelvic bone arch interference. CONCLUSIONS: At the present time, there is no evident dosimetric superiority of one Bt method when all the criteria are taken into account. However, improving Bt techniques to implant any prostatic size could found the superiority of the 125I or permanent implants. 125I indeed allows large hyperdosage volumes inside the CTV in comparison with 192Ir HDR techniques while lowering doses to OR and minimizing CS.

Adenocarcinoma↗