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PubMed1988

[Endoluminal irradiation of tracheobronchial tumors using a high dose rate iridium-192 afterloading device].

We report about 50 patients with inoperable bronchus tumors treated since March 1986 in a prospective non randomized study with high dose rate iridium-192 afterloading (AL) irradiation in 140 applications. 26 patients were treated combined with external irradiation. 32 were treated before with laser therapy, one with chemotherapy (small cell carcinoma). The actuarial survival rate (Kaplan-Meier) was 26% after 36 weeks for all patients; 38% for combined endoluminal and external irradiation and 9% for patients treated with AL alone. Death was caused by the local tumor in 85%. In 41% lethal bleeding was seen.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1987

Carcinoma of the female urethra: combined iridium Ir 192 interstitial and external beam radiotherapy.

Three female patients (mean age 55) with carcinoma of the urethra were treated with combined external beam irradiation (4,000 to 5,000 rads) and interstitial irradiation with iridium Ir 192 (2,700 to 3,000 rads) applied with a modified Syed-Neblett template. Two patients are alive with no evidence of disease at 27 and 37 months. One patient died of a second primary tumor at 30 months, without histologic evidence of the original urethral neoplasm. No patient had significant complications of therapy. This treatment regimen is effective for selected women with urethral carcinoma.

Adenocarcinoma↗
PubMed1987

[Conservative treatment of bladder epitheliomas by partial cystectomy and iridium-192 curietherapy].

From 1971 to 1979, 55 patients were treated for bladder cancer at the Henri-Mondor Hospital using a treatment protocol combining low dose pre-operative external beam radiation followed by iliac node dissection, limited partial cystectomy (or sometimes for T1 tumors, a trans-urethral resection) and curietherapy with iridium 192. The 5 year disease free survival was 37/55 (67%). The rate of local recurrences plus second tumors within the bladder was 16% (9/55). These results are compared with other conservative modalities of treatment of bladder cancer.

Adult↗
PubMed1988

[Postoperative irradiation of carcinoma of the corpus uteri using the iridium afterloading technic].

From 1981 to 1986 a prospective study was conducted of University of Vienna, 1st gynecology department, for 708 patients with operated and postoperatively irradiated endometrial cancer. These patients were treated by total hysterectomy, bilateral salpingo-oophorectomy and postoperative vaginal irradiation with high-dose-afterloading (iridium 192). A percutaneous irradiation (cobalt 60) was done in stage I cases only when myometrial infiltration was deep. Highly differentiated tumors with infiltration of the first and second third of the myometrium were treated by vaginal irradiation alone. Poorly differentiated tumors (G2, G3) with infiltration of the second and third third of the myometrium were treated by vaginal and percutaneous irradiation. A group of 125 cases with good prognosis (infiltration 1/3, G1) and with postoperative vaginal irradiation alone had the same five-year-survival of 83% as a group of 152 cases with bad prognosis (infiltration 2/3 and 3/3, G2 or G3) treated by vaginal and percutaneous irradiation. This result shows clearly the importance of additional irradiation of the pelvis in cases with bad prognosis factors. The incidence of radiation side effect in all 708 cases was: cystitis 4.6%, proctitis 5.2%, vaginal or rectal ulcers 1.4% and fistulas 0.2%. Cases with vaginal irradiation alone and with the optimal intravaginal fraction dose of 700 cGy (twice) had the lowest level of side effects: cystitis 3.8%, proctitis 2.1%, vaginal necrosis 0.7%, no further severe complications. None of the patients with postoperative vaginal irradiation alone had a vaginal recurrence. The incidence of recurrences in 708 patients was 1.6%. All recurrence cases in stage I (0.7%) had bad prognosis factors and were treated with vaginal and percutaneous irradiation. It is concluded that primary surgery of endometrial cancer should be followed by postoperative vaginal radiation. It appears that the remote afterloading treatment for vaginal radiation produces minimally complications and gives complete protection from radiation exposure to the medical staff. With additional external radiation in high-risk cases the same good result can be achieved as in cases with low-risk and vaginal radiation alone.

Adult↗
PubMed1988

[Treatment of inoperable endometrial carcinoma with intracavitary high-dose rate iridium irradiation].

Surgery should be an integral part of the management of the patient with endometrial cancer. Only patients with severe medical conditions should be treated with radiation therapy alone. Although radiation therapy alone often can cure endometrial cancer, five-year-survival figures are poorer than for operation. At the University of Vienna, I. Department of Gynecology, 198 patients with endometrial cancer were treated by radiation therapy alone. Using the afterloading-iridium-192-technique, the three-year-survival-rate was 76%, five-year-survival 60%. A comparable group of 185 cases treated by intracavitary radium-226 had five-year-survival of only 40% (p less than 0.001). With afterloading high-dose irradiation younger patients had five-year-survival of 75%, older patients (70 years and more) 51%; when tumor grading was one survival figures reached 76%, with tumor grading 2 and 3 only 41%. Severe radiation side effects did not occur with the optimal intrauterine single dose of 850 cGy (four times) and 700 cGy intravaginal (once), nor could any severe complications be observed when the total rectal dose did not exceed 500 cGy. In only 8% of the cases the treatment was combined with external irradiation (Cobalt-60). Intrauterine and intravaginal applications were performed without anaesthesia and the hospitalisation time was very short.

Age Factors↗
PubMed1984

[Role of iridium-192 endocurietherapy in the treatment of T1 and T2 tumors of the tonsillar region].

From July 1971 to August 1981, 31 selected patients with T1, T2 tumours of the Tonsillar region were treated according to the following protocol: Telecobalt therapy to the primary site and to neck nodes to a dose of 45 Gy, Brachytherapy to the primary site to a dose of 25-30 Gy using iridium 192, Boost dose to involved neck nodes, with electrons, or radical neck dissection, wether N1, N2 or N3. The actuarial survival free of disease is 76% for the whole group and 86% for the NO group. The local control rate is 100% without any recurrences at the primary site having been observed. Disease control in the neck is 94% overall and 100% for the NO group. The effects on salivary function were reduced in comparison with telecobalt therapy alone. These favourable results favour the use of this protocol for superficial, minimally infiltrating tumours less than 4 cm in diameter without obvious extension to the base of the tongue or retromolar trigone.

Adult↗
PubMed1984

[Restriction of indications and first results with the high-dose rate-afterloading technic (iridium-192)].

First experiences with high-dose-afterloading technique (Iridium-192) at the Department for Radiotherapy of the Gynecologic-University-Clinics in Vienna are reported. 1300 applications in about 500 patients were performed. With the one-sound Buchler-apparatus theoretically all forms of isodoses are possible, but in practice we have restricted the indications. Only Radium uterine sounds as well as radium vaginal applications were replaced by high-dose-afterloading technique. Generally only primary or postoperative treatment of endometrial carcinoma was performed. The easy sounding of the uterine cavum is another reason for this restriction of indications. The first results of radiotherapy of endometrial cancer yet shows little better survival rates without any increase of side effects.

Age Factors↗
PubMed1984

Iridium-192 wiring after partial cystectomy as a treatment of small malignant bladder tumors.

Small tumors of the mobile portion of the bladder may be treated by means of interstitial irradiation by iridium-192 wiring. Forty-four tumors (mostly T1, but also T2 and T3) were treated by this procedure and followed over five years. Good results are attained in 66 per cent of the cases. This method has the benefit of avoiding irradiation to the surgeon's hands, and of delivering to a specific site a dose of 6,000 rads. No bladder contraction was observed. Supplementary treatment by irradiation has to be considered in view of frequent recurrences of malignant bladder tumors after transurethral resection of partial cystectomy. In small cancers slightly infiltrating the bladder wall, many attempts have been made to replace tele-irradiation by interstitial irradiation. The latter delivers specifically high rad dosage to the involved area. Radium needles has been used in France by Darget before 1951 but evaluation of accurate dosage proved difficult. This material was dangerous to the surgeon's hands, and the procedure lead frequently to bladder sclerosis. This technique is currently used by Van der Werf-Messing in Rotterdam. She strongly advises preoperative tele-irradiation (3 X: 350 rads) to prevent tumor implants in the scar. An intravesical balloon filled with fluid radioisotope of gold-198 or cobalt-60 has been used for diffuse malignant papillary epithelioma. It was discontinued because of radiation cystitis and subsequent contraction of the bladder. Recently in well-limited tumors, Bloom and Wallace have used Tantalum-182 needles which have interesting physical properties (high energy and short half-life period) (2).

Brachytherapy↗
PubMed1980

Stereotactic treatment of brain lesions. Biopsy, interstitial radiotherapy (iridium-192 and iodine-125) and drainage procedures.

Integrating CT imaging techniques into stereotactic procedures makes it easy to puncture cysts, take biopsies from neoplastic and nonneoplastic lesions, and place radioactive material in tumors at exact and reproducible sites. A stereotactic program of interstitial radiotherapy in deep-seated brain tumors has been applied in 326 cases as of December 31, 1979 (270 cases using iridium-192 and 56 cases using iodine-125). The use of iodine-125 is now favored since it requires less radiation protection due to its soft 28-35 keV radiation; at the same time, however, it possesses a comparable half life of 60 days. In 126 cases, stereotactic biopsy was used exclusively for diagnostic purposes followed by open craniotomy or conventional radiation. Cystic brain tumors (i.e., craniopharyngiomas and cystic low grade gliomas) were permanently drained by insertion of Rickham reservoir catheters in 61 cases. Stereotactic ventriculocisternostomies were carried out in cases of hydrocephalus and drainage of suprasellar arachnoid cysts was performed in 15 cases. A simple method of projecting CT images onto stereotactic X-ray pictures provides an exact mapping of lesions within the actual stereotactic brain space. The results of this series of patients strongly suggest that exploratory craniotomies and free-hand punctures can no longer be advocated. No radiation treatment should be considered without histological confirmation. The more clearly the volume of a tumor can be defined, the more favorable the results of interstitial irradiation in otherwise unresectable tumors.

Biopsy↗
PubMed1981

[Secondary amputation of the penis in the sequelae of local therapy with iridium 192 for carcinoma (author's transl)].

The author reports 4 cases of severe delayed irradiation complications which required partial or complete secondary amputation of the penis for sequelae of local therapy with Iridium. After reviewing the modes of spread of carcinoma of the penis and the various therapeutic possibilities in the light of these 4 cases, the author raises the question as to whether such conservative treatment by interstitial radiotherapy is well-founded. He would tend to suggest immediate surgery giving an identical result at the price of much shorter treatment and which would be free of the complications reported following radiotherapy.

Aged↗
PubMed1994

A new iridium applicator for vaginal vault irradiation.

A new disposable gynecologic applicator designed for postoperative vaginal vault brachytherapy is presented. The applicator is afterloading manually with iridium 192 wire. We have used this new applicator in more than thirty patients and recorded the following advantages: 1) There is no need to install expensive and complicated equipment; 2) Single use applicators are in sterile packages and are ready to use; 3) Applicator is easily and comfortably carried by patient; 4) There is no need for specific training to use the system; 5) There is no need for general anesthesia during application; 6) There is no need for patient immobilization during treatment; 7) There is no need for urinary catheterization during treatment; 8) Dose distribution is homogeneous; 9) Bladder and rectum doses are at acceptable levels; 10) Radioprotective measures needed to be taken are inexpensive. We believe that this new system could easily be used in every radiation oncology unit.

Brachytherapy↗
PubMed1993

[Radiation sensitivity of the normal bile duct during high dose rate afterloading irradiation with Iridium 192. Experimental studies in pigs].

This animal study was designed to assess the tolerance of the normal bile duct to a single intraluminal high-dose-rate afterloading irradiation. This information is essential for treatment recommendations in irradiation therapy of malignant bile duct stenoses. In 16 pigs bile duct catheters were inserted surgically. Over these devices single intraductal doses of 7.5 Gy and 15 Gy were applied using an iridium-192 source. After a period of two to three months the bile ducts and the surrounding structures were investigated by means of cholangiography, angiography, and macropathological and histological investigations. A single intraductal dose of 7.5 Gy leads to a slightly scarred shrinkage of the bile duct with sclerosis and obliteration of the capillary vessels. Vasculitis and necrosis of the bile duct wall are still evident three months after irradiation. A single dose of 15 Gy leads to severe lesions with widespread necroses of the bile duct wall which tend to bleed, and result in a high degree of shrinkage of the bile duct. The radiation damage is most prevalent near the papilla and in the narrow segments near the liver. Single intraluminal high-dose-rate afterloading doses of 7.5 and 15 Gy cause significant lesions and complications at the bile ducts. As the intact bile duct is the Achilles heel of intraductal therapy, considerably lower single doses are recommended for a fractioned treatment.

Animals↗
PubMedDate not supplied

Conformal high dose rate iridium-192 boost brachytherapy in locally advanced prostate cancer: superior prostate-specific antigen response compared with external beam treatment.

PURPOSE: Prostate-specific antigen levels are used to judge disease control of prostate cancer. No published data attest to the greater ability of conformal brachytherapy to control disease compared with conventional radiation at a single institution. This report compares the biochemical response rates in patients with stages T2b to T3c prostate cancer treated with conformal brachytherapy boost and external beam radiation with the rates in patients treated with conventional external radiation alone. MATERIALS AND METHODS: From November 1991 through November 1995, 58 patients received 45.6 Gy pelvic external irradiation and three high dose rate iridium-192 conformal boost implants of 5.5 to 6.5 Gy each. They were compared with 278 similarly staged patients treated from January 1987 through December 1991 with external beam radiation to prostate-only fields (median dose 66.6 Gy). No patient received androgen deprivation. Patient outcome was analyzed for biochemical control. Biochemical failure was defined as a prostate-specific antigen level > 1.5 ng/mL and rising on two consecutive values. If serial posttreatment prostate-specific antigen levels were showing a continuous downward trend, failure was not scored. RESULTS: Median follow-up was 43 months for the conventionally treated group and 26 months for the brachytherapy boost group. The median pretreatment prostate-specific antigen level was 14.3 ng/mL for the external-beam-radiation-alone group and 14.0 ng/mL for the brachytherapy boost group. The median Gleason scores were 6 and 7, respectively, for the two groups. The biochemical control rate was significantly higher in the brachytherapy boost treatment group. Three-year actuarial biochemical control rates were 85% versus 52% for the conformally and conventionally treated patients, respectively. In a multivariate analysis, the use of conformal brachytherapy boost and pretreatment prostate-specific antigen level were significant prognostic determinants of biochemical control. The 3-year actuarial rates of biochemical control for conformally versus conventionally treated patients, respectively, were 83% versus 72% for a pretreatment prostate-specific antigen level of 4.1 to 10.0 ng/mL, 85% versus 47% for a prostate-specific antigen level of 10.1 to 20.0 ng/mL, and 89% versus 29% for prostate-specific antigen > 20 ng/mL. When the analysis was limited to patients in both groups with a minimum 12-month follow-up, the brachytherapy boost group continued to show a higher biochemical control rate compared with the conventional radiation group (3-year actuarial rates of 86% vs 53%). DISCUSSION: These preliminary results show a significant improvement in the biochemical response rate with conformal boost brachytherapy and pelvic external radiation compared with conventional radiation alone. These results, coupled with our previously reported acceptable toxicity rates, support the use of this technique.

Aged↗
PubMed1998

Antibacterial activity of rhodium, iridium, and ruthenium tripodal phosphine complexes.

Twenty-eight rhodium, iridium, or ruthenium complexes were evaluated for their in vitro antibacterial activity against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922 and Pseudomonaa aeruginosa ATCC 27853. Ten compounds showed an antibacterial activity against Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 29213 with a range of the minimum inhibitory concentrations (MICs) between 16 and 125 micrograms/ml. None of the compounds exhibited antimicrobial activity against the gram-negative strains E. coli ATCC 25922 or Pseudomonas aeruginosa ATCC 29213 with a concentration range between 4 and 500 micrograms/ml.

Anti-Bacterial Agents↗
PubMed2000

Enantioselective hydrogenation of olefins with phosphinooxazoline-iridium catalysts.

Cationic iridium complexes with chiral phosphinooxazoline ligands are efficient catalysts for the enantioselective hydrogenation of olefins. The complexes are readily prepared, air-stable, and easy to handle. In contrast to chiral rhodium- and ruthenium-phosphine catalysts, they do not require the presence of a polar coordinating group near the C=C bond. In the hydrogenation of unfunctionalized trisubstituted 1,2-diaryl-olefins, high enantioselectivities of >95% ee with full conversion and turnover frequencies of >7,000 h-1 can be achieved, using 0.1 mol% of catalyst with tetrakis[3, 5-bis(trifluoromethyl)phenyl]borate (TFPB or BARF) as the counterion. The corresponding hexafluorophosphate or tetrafluoroborate salts give low conversion due to deactivation of the catalyst during the reaction. Substrates with polar substituents such as allylic alcohols, on the other hand, afford better results with the hexafluorophosphate salts.

Journal Article↗
PubMed2001

Reactions of the allenylidenes trans-[IrCl[=C=C=C(ph)R](PiPr3)2] with electrophiles: generation of butatriene-, carbene-, and carbyne- iridium complexes.

The allenylidenciridium(I) complexes trans-[IrX(=C=C-CPh2)(PiPr3)2] (X = Cl: 1; X = I: 2) react with excess methyl iodide by C-C coupling and elimination of HI to give the eta2-butatriene compounds trans-[IrX-(eta2-CH2=C=C=CPh2)(PiPr3)2] (3, 4), of which 3 (X = Cl) was characterized by X-ray crystallography. Treatment of 1 and 5 (containing C=C=C(Ph)tBu as the allenylidene ligand) with HCI leads to the formation of the six-coordinate hydridoiridium(III) complexes [IrHCl2[= C=C=C(Ph)R](PiPr3)2] (6, 7) by oxidative addition at the metal center. In contrast, the reactions of 1 and 5 with both CF3CO2H and CF3SO3H afford the four-coordinate vinylcarbene compounds trans-[IrCl[=C(X)-CH=C(Ph)R[(PiPr3)2] (8-10). For X= CF3CO2, in nitromethane a dissociation of the C-X bond occurs and the cationic iridium carbynes trans-[IrCl[=C-CH=C(Ph)R](PiPr3)2]+ are generated. Upon addition of NaBPh4, the stable carbyne complexes 11b (R= Ph) and 12b (R = tBu) with BPh4 as the counterion were isolated in almost quantitative yields. The X-ray crystal structure analysis of 6 reveals that the chloro ligands are cis and the phosphane ligands trans disposed.

Journal Article↗
PubMed2002

Structural and dynamic studies on amido-bridged rhodium and iridium complexes.

Treatment of [[M(mu-Cl)(diolefin)](2)] with the lithium salts of primary and secondary amines (LiNRR') in diethyl ether affords the complexes [[M(mu-NRR')(diolefin)](2)] (M=Rh, Ir; diolefin=1,5-cyclooctadiene (cod), tetrafluorobenzobarrelene (tfb); R'=H, R=tBu, Ph, 4-MeC(6)H(4); R=R'=Ph, 4-MeC(6)H(4)). Mixed-bridged chloro/amido complexes are intermediates in these syntheses, two of which, [[Rh(cod)](2)(mu-NHR)(mu-Cl)] (R=tBu, 4-MeC(6)H(4)), have been isolated. Replacement of the diolefin ligands by carbon monoxide or tert-butyl isocyanide in selected compounds takes place with retention of the binuclear structure to give the corresponding complexes [[M(mu-4-HNC(6)H(4)Me)(CO)(2)](2)], [[Rh(mu-4-HNC(6)H(4)Me)(CNtBu)(2)](2)] (12), and [[Rh(mu-NPh(2))(CNtBu)(2)](2)] (13). Single-crystal X-ray diffraction analyses of the complexes [[Rh(mu-NRR')(cod)](2)] (R'=H, R=4-MeC(6)H(4) (3); R=R'=4-MeC(6)H(4) (5)), 12, and 13 have shown that the conformation of the "RhN(2)Rh" four-membered metallacycle is planar in 5 and folded in 3, 12, and 13. The complexes with primary amides, 3 and 12, were found to exist as the syn,endo stereoisomers. The fluxionality of the complexes with secondary amides is due to rotation of the aromatic substituents about the N-C(ipso) bond and, in the case of 13, to the inversion of the "RhN(2)Rh" metallacycle as well. The complexes [[M(mu-NHR)(cod)](2)] (R=Ph, 4-MeC(6)H(4)) were found to exist as isomeric mixtures in solution, the syn/anti ratio being 2:3 for the rhodium derivatives and 1:1 for their iridium counterparts. Again, the motion detected was due to rotation of the aromatic substituents, and could be frozen only in the case of the syn isomers. The complex [[Rh(mu-NHtBu)(cod)](2)] with aliphatic amido ligands was found to be the anti folded isomer and proved to be nonfluxional. The most common conformation of the "RhN(2)Rh" metallacycle in these compounds is folded, and the preferred configuration varies from syn for the less encumbered compounds to anti on increasing the bulkiness of the bridging and ancillary ligands.

Journal Article↗
PubMed2004

Chiral iridium [corrected] xyliphos complexes for the catalytic imine hydrogenation leading to the metolachlor herbicide: isolation of catalyst-substrate adducts.

Iridium complexes relevant to the catalytic enantioselective hydrogenation of 2-methyl-6-ethylphenyl-1'-methyl-2'-methoxyethylimine (MEA-imine, 1) in the Syngenta Metolachlor (3) process were prepared and characterized. Reaction of the diphosphane (S)-1-[(R)-2-(diphenylphosphanyl)ferrocenyl]ethyldi(3,5-xylyl)phosphane ((S)-(R)-Xyliphos, (S)-(R)-4) with [Ir(2)(micro-Cl)(2)(cod)(2)] (cod=1,5-cyclooctadiene) afforded [Ir(Cl)(cod)[(S)-(R)-4]] (7), which reacted with AgBF(4) to form [Ir(cod)[(S)-(R)-4]]BF(4) (8). Complexes 7 and 8 reacted with iodide to yield [Ir(I)(cod)[(S)-(R)-4]] (9). When 9 was treated with one and two equivalents of HBF(4), two isomers of the cationic Ir(III) iodo hydrido complex [Ir(I)(H)(cod)[(S)-(R)-4]]BF(4) were solated (10 and 11, respectively). Complex 9 was oxidized with one equivalent of I(2) to give the iodo-bridged dinuclear species [Ir(2)I(2)(micro-I)(3)[(S)-(R)-4](2))]I (12). [Ir(2)(micro-Cl)(2)(coe)(4)] (coe=cyclooctene) reacted with (S)-(R)-4 to yield the chloro-bridged dinuclear complex [Ir(2)(micro-Cl)(2)[(S)-(R)-4](2)] (13). Complexes 7-12 were structurally characterized by single-crystal X-ray diffraction and tested as single-component catalyst precursors for enantioselective hydrogenation of MEA-imine. Complex 10 and dinuclear complex 12 gave the best catalytic results. Efforts were also directed at isolating substrate- or product-catalyst adducts: Treatment of 8 with 2,6-dimethylphenyl-1'-methyl-2'-methoxyethylimine (DMA-imine, 14, a model for 1) under H(2) allowed four isomers of [Ir(H)(2)[(S)-(R)-4](14)]BF(4) (18-21) to be isolated. These analytically pure isomers were fully characterized by 2D NMR techniques. X-ray structural analysis of an Ir(I)-imine adduct, namely, [Ir(C(2)H(4))(2)(14)]BF(4) (25), which was prepared by reacting [IrCl(C(2)H(4))(4)] with [Ag(14)(2)]BF(4) (16), confirmed the kappa(2) coordination mode of imine 14.

Journal Article↗