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PubMed1985

Iridium-192 implants in the treatment of tonsillar region malignancies.

A total of 127 patients with histologically proved diagnosis of carcinoma of the tonsillar region and soft palate were treated over the past ten years utilizing interstitial iridium-192 implants. Eighty patients were treated for primary tumors and 47 patients for either recurrent or persistent tumors after definitive irradiation and/or surgery. All patients with primary tumors were treated by a combination of external megavoltage irradiation and interstitial iridium-192 implants, whereas patients with recurrent tumors were treated by interstitial implants alone. In the primary group, 95% of patients with T1 and T2 lesions and 79% with T3 and T4 lesions achieved complete local tumor control. The three-year absolute disease-free survival rate was 72%. Seventy-five percent local tumor control was obtained in patients with recurrent disease, with two-year absolute disease-free survival of 42%. Treatment-related complications such as soft-tissue necrosis or osteoradionecrosis occurred in 6% of patients in the primary group and 23% in recurrent group. This treatment regimen offers an excellent locoregional control with no significant functional or esthetic impairment. Most patients with primary lesions who fail this regimen can be salvaged by surgery or reirradiation using interstitial implants. Reirradiation with interstitial implants is feasible and offers a good chance of long-term local tumor control in the selected group of patients with recurrent disease for whom external irradiation and/or surgery had not been successful.

Adult↗
PubMed1991

Combined surgical resection and iridium 192 implantation for locally advanced and recurrent desmoid tumors.

Thirty-eight histologically confirmed desmoid tumors were treated with conservative surgical resection and interstitial iridium 192. Patients included in this series constituted a poor prognostic group. Seventy five percent (75%) had previous recurrences of their disease and 50% had tumors 8 cm or greater in size. In addition, 16% of the patients had gross residual disease after surgical excision and 79% had positive or close margins of resection. With a median follow-up of 5.5 years, the 5-year actuarial in-field local control rate was 75% and the overall local control rate was 66%. Four of the 12 local recurrences developed at the periphery of the implant volume and four patients failed at least 3 cm or more beyond the treated volume. After salvage therapy, the 5-year actuarial local control rate was 95%. Two patients required amputation for recurrent disease. Thirty of 34 patients remain free of disease with an excellent functional result achieved. The authors conclude that surgical resection and postoperative interstitial iridium 192 is effective therapy for patients with desmoid tumors. Despite the fact that most patients in this series had bulky, recurrent tumors, excellent long-term local control and limb function were achieved.

Adolescent↗
PubMed1995

Endobronchial radiation therapy for obstructing malignancies: ten years' experience with iridium-192 high-dose radiation brachytherapy afterloading technique in 365 patients.

From 1983 to 1993, 365 patients with obstructing endobronchial malignancies were treated by endobronchial high-dose radiation (HDR) iridium-192 afterloading. In 346 patients, the objective was palliation, and in 19, the objective was curative. A dose of 5 Gy at 10 mm from the source axis was administered on three (palliation) and four (cure) occasions, at intervals of 14 days. The majority of patients were treated after exhaustion of external beam radiation therapy (EBRT), often in conjunction with other interventional bronchologic modalities such as endobronchial laser resection. Of the patients, 65% had a squamous cell carcinoma. Endobronchial HDR brachytherapy results in few acute complications and can be performed with no major discomfort on an outpatient basis. In approximately 66% of patients, a palliative effect is achieved, even after the exhaustion of conventional treatment. Life may be prolonged for a few months, but the enhancement of survival is difficult to assess for several reasons. Mean survival is 9 months for limited disease and 5 months for extensive disease. Endobronchial HDR brachytherapy influences the pattern of failure: a 21% rate of fatal hemorrhages is probably the result of the selection of patients for this treatment rather than a treatment-related complication. There is sufficient evidence to suggest the rational use of HDR brachytherapy in combination with EBRT to effect a cure, or even on its own when tumor growth is strictly limited. However, the standardization of radiotherapy and endoscopic indications is an urgent priority. Prospective, controlled, and cooperative studies are mandatory. Endobronchial iridium-192 HDR brachytherapy complements endobronchial laser resection and is currently an established technique in the treatment of advanced malignant airway obstruction.

Airway Obstruction↗
PubMed1997

Iridium 192 high-dose-rate brachytherapy--a useful alternative therapy for localized prostate cancer?

We report on a novel protocol involving iridium 192 high-dose-rate brachytherapy and follow-up of up to 130 months in patients with prostatic carcinoma. Using regional anesthesia, five to seven hollow needles are placed within the prostate by perineal puncture under ultrasound guidance. A 9-Gy prostate dose is applied followed by 30 min of hyperthermia (since 1991). This treatment is repeated once after 7 days; 2 weeks later, 18 x 2-Gy external beam radiation (small-field prostate) is added as percutaneous dose saturation. Since 1984 we have treated 40 patients with this protocol. Local tumor control was achieved by means of prostatic biopsy at 18 months after therapy and determination of prostate-specific antigen (PSA) values in about 70% of the patients; after a mean follow-up period of more than 6 years (16-130 months), 80% of the patients show either no evidence of disease or stable disease. We therefore conclude that iridium 192 high-dose-rate brachytherapy is a useful alternative in the treatment of localized prostate cancer in patients who are not eligible for radical prostatectomy.

Adult↗
PubMed1998

Brachytherapy with iridium-192 HDR to prevent from restenosis in peripheral arteries. An update.

The use of stents does not appreciably improve restenosis (usually resulting from intimal hyperplasia) as compared to percutaneous transluminal angioplasty (PTA) alone. The development of small-caliber probes for afterloading therapy in the biliary tract allowed us to use these for therapy in the vascular system. Using a special 9 F catheter, exact measurement of the length of the stented vascular segment and of the insertion length of the afterloading probe could be reproducibly performed. We used a Nucletron (Micro) Selectron HDR planning system version 10.10 for exact calculation, monitoring, and control of the afterloading procedure. Our source was iridium 192 (10 Ci) with a diameter of 1.1 mm. The program controls and monitors the insertion and removal of the iridium probe from the source into the special catheter through to the tip, and monitors the irradiation duration. The exposure time was around 200 seconds for a surface dose of 12 Gy. To date, a total of 40 patients have been treated with endovascular afterloading. All patients suffered from clinically relevant reocclusions or restenoses in stented vascular segments of the superficial femoral artery following successful PTA or laser treatment, within 6 to 8 months after the last therapy. In all patients it was possible to perform re-PTA treatment without remaining residual stenoses in the stented region. The additional time required as compared to PTA alone was approximately 45 minutes with most of this time spending for transportation between the cath lab and afterloading room. The follow-up period of the 40 patients ranged from 4 months to 71/2 years. In 33 patients, there was no deterioration of the clinical stage and no restenosis. One patient suffered from an acute thrombosis approximately 3 months after stent implantation, another patient had a stenosis 3 cm above the stented vascular segment 12 months after irradiation treatment. Follow-up examinations have revealed no evidence of nerve lesions following irradiation therapy. The tissue surrounding the artery showed no change following irradiation therapy, either in the CT, color-coded Doppler, endovascular ultrasonic scan or MRI. No complaints of discomfort were reported during or after irradiation. With the exceptions mentioned above, there was no evidence of any complications.

Aged↗
PubMed2001

Transperineal low-dose rate iridium-192 interstitial brachytherapy in cervical carcinoma stage IIB.

PURPOSE: To assess local control, survival and complications in patients with cervical carcinoma Stage IIB treated radically with transperineal Iridium-192 low-dose rate interstitial brachytherapy following external beam radiotherapy. PATIENTS AND METHODS: 65 women (age 25-70 years, mean 47 years) with cervical carcinoma Stage IIB were initially treated with external beam radiotherapy on a telecobalt or 6 MV linear accelerator to a dose of 50 Gy delivered in 5-6 weeks. After 2-3 weeks of completing external radiation, patients received interstitial brachytherapy with Iridium-192 (activity 0.5-1 mCi/cm) using a Syed-Neblett perineal template. The median dose delivered to the implant volume was 24 Gy (range 20-32 Gy) delivered at an average dose rate of 0.70 Gy/h (range 0.40-1.20 Gy/h). A point defined at 1.5 cm lateral to the central uterine tandem at the level of os was taken as a representative for assessing the dose to the cervix. Mean doses delivered by interstitial brachytherapy to point A, cervix, point B and rectum were 38 Gy, 34 Gy, 16 Gy and 16 Gy, respectively. RESULTS: At a median follow-up of 53 months, the actuarial disease free survival and overall survival for 65 patients at both 5 and 10 years was 64% and 44%, respectively. Response to radiotherapy was a strong predictor of local control with 82% of patients continuing to have pelvic control after initial complete response. Overall, nine (14%) patients had persistent disease, ten (15%) developed a central recurrence after initial control and three patients developed distant metastasis on follow-up. No patient had any immediate treatment-related complication. Late toxicity included grade I-II rectal reactions in five patients and grade IV bladder complication (vesico-vaginal fistula) in two patients. 5 years after treatment, one patient developed intestinal obstruction, which was relieved after conservative management. Two patients developed vaginal stenosis. The 5- and 10-year disease free survival was 48% in patients aged less than 45 years as compared to 80% in patients of more than 45 years (p = 0.009). Dose to the cervical point was a prognostic indicator with 5- and 10-year disease free survival of 47% in patients who received < 35 Gy in comparison to 80% in patients who had > 35 Gy (p = 0.03). There was no difference in local control and survival in patients with minimal and moderate parametrial involvement. Bulky disease (> 4 cm) at presentation and a longer gap between external radiation and brachytherapy showed a trend towards inferior local control. CONCLUSIONS: Interstitial brachytherapy after external beam irradiation in patients with cervical carcinoma Stage IIB results in acceptable local control, survival and complication rates. Increased dose to the cervical disease results in improved local control and survival and should therefore be considered while optimizing brachytherapy treatment plans. Comparison of the results with those of standard intracavitary therapy remains to be proven in a randomized trial.

Adenocarcinoma↗
PubMed1997

[Pretarsal platinum-iridium implants for therapy of lagophthalmos in facial paralysis. Preliminary results].

UNLABELLED: Upper lid closure in facial nerve paresis induced lagophthalmos is often improved by implantation of gold weights. However, the tolerability of gold implants has not always met expectations. We therefore investigated whether results could be improved by implantation of well-tolerated platinum implants. PATIENTS AND METHODS: Three patients with lagophthalmos received pretarsal platinum-iridium implants in the upper lid. The implants were primary in two patients and secondary in one. In this patient, the previous gold implant had led to marked swelling and redness of the upper lid 6 weeks after surgery. The platinum implants were prefabricated with a radius of 20 mm and weighed between 1.3 and 1.4 g. During implantation, they were individually contoured to fit lidcurvature and attached pretarsally with nonresorbable thread. RESULTS: Postoperatively, the upper lid of all three patients could be closed completely. The implants healed without irritation. No lid swelling occurred during 2-to 6-month follow-up. Because platinum-iridium alloys have a higher specific gravity (Ptlr 90/10 = 21.65 g/cm3) than gold (18.43 g/cm3), they can attain equal weight at smaller size. CONCLUSIONS: Our first results show that platinum implants are a feasible alternative to gold implants in treating lagophthalmos due to better biocompatibility and higher specific gravity.

Adult↗
PubMed1978

Antitumor action of rhodium (I) and iridium (I) complexes.

Several rhodium(I) and iridium(I) complexes displayed different degrees of antitumour activity when tested in mice bearing Ehrlich ascites carcinoma. Rhodium (I) and iridium (I) acetylacetonate derivatives caused a high percentage of cures. The rhodium (I) dimers were particularly interesting, since (bis(cycloocta-1,5-diene)micromicron' dichlorodirhodium(I) [RhCODCl]2) was highly effective, whereas its analogues, bis(bicyclo[2,2,1]hepta-2,5-diene)micromicron'-dichlorodirhodium(I) [RhNBDCl]2) and bis(1,5-hexadiene)micromicron' dichlorodirhodium(I) [RhEDCl]2) were virtually inactive. The absence of significant inhibition of DNA, RNA and protein syntheses in tumour cells found for [RhCODCl]2 at therapeutically active dosages, indicates that this substance has a different mechanism of action from that of cis-dichlorodiammine Pt(II) (cis-PDD). The amount of rhodium found in tumour cells after administration of active [RhCODCl]2 was higher than that for [RhEDCl]2, while the rhodium concentration in the ascitic fluid was much higher for [RhEDCl]2. A mechanism based on the chemical properties of the complexes is tentatively proposed for explaining these findings and selective toxicity for tumour cells.

Animals↗
PubMed1981

Intracavitary irradiation of renal pyelocalyceal transitional cell carcinoma with iridium-192.

A case of multicentric urothelial transitional cell carcinoma is presented, in which the patient underwent a left ureteronephrectomy and in the remaining right kidney recurrent transitional cell carcinoma was found in the inferior calyx. Because this area was accessible via a cutaneous nephrostomy, it is treated with a combination of external beam radiation and intracavitary implantation with iridium-192. The iridium was placed in the vicinity of the tumor using an angiographic procedure. The technique successfully preserved remaining renal parenchyma. The case illustrates how angiography skills and procedures can be applied in a novel brachytherapy application.

Angiography↗
PubMed1993

Treatment of T3a bladder cancer with iridium implantation.

A total of 7 patients with high grade, T3a (Stage B2) bladder cancer were treated with external radiation therapy and interstitial iridium implantation from May 1986 through March 1988. Follow-up has ranged from nineteen to sixty-one months with a median of forty months. One patient has required a cystectomy and is currently free of disease, and 1 patient has had recurrence of his cancer and metastatic carcinoma has developed; 5 are free of disease and have maintained their usual state of bladder function. Iridium implantation maintains bladder function and is effective therapy for selected individuals with localized, muscle-invading bladder cancer.

Aged↗
PubMed1995

Iridium-192 versus cobalt-60 boost in 3-7 cm breast cancer treated by irradiation alone: final results of a randomized trial.

This prospective randomized trial compared an iridium-192 implant boost with a cobalt-60 external irradiation boost to the primary tumor site, in 255 patients with breast cancers 3-7 cm in diameter. All patients had a partial (> 50%) or complete response following primary external beam irradiation of 58 Gy to the whole breast, as well as irradiation to the axillary, supraclavicular and internal mammary nodes. Patients with clinically positive axillary nodes also received a cobalt-60 10-15 Gy boost to the inferior axilla. All patients had core biopsy only. Both groups were comparable in age, tumor size, node involvement, grade, and progesterone receptor levels. The boost dose was 20 Gy in both groups. At the median 8-year follow-up, the breast recurrence risk was 24% in the iridium group and 39% in the cobalt group (p = 0.02). When adjusted to other prognostic and treatment factors, the brachytherapy boost decreased the breast recurrence risk by 60%. The 8-year breast preservation rates were 81% and 67%, respectively (p = 0.024). Cosmetic outcome in both groups was evaluated in 120 patients with a minimum 3-year follow-up and was comparable in both groups. This study demonstrates that in selected patients with large tumors treated with irradiation alone, local control and breast preservation rates are improved by the use of brachytherapy to boost the primary tumor.

Adult↗
PubMed1995

Early breast cancer: influence of type of boost (electrons vs iridium-192 implant) on local control and cosmesis after conservative surgery and radiation therapy.

Between December 1981 and December 1988, 329 consecutive patients with stage I and II breast cancers who underwent wide excision (n = 261) or quadrantectomy (n = 68) with (n = 303) or without (n = 26) axillary dissection were referred to radiotherapy. Final margins of resection were microscopically free from tumor involvement in all cases. Radiotherapy consisted in 40-45 Gy over 4-4.5 weeks to the breast, with (n = 168) or without (n = 161) regional nodal irradiation of 45-50 Gy over 4.5-5 weeks. A mean booster dose of 15 Gy was delivered to the primary site by iridium-192 implant in 169 patients (group 1) or by electrons in 160 patients (group 2). Twenty-seven percent (n = 88) of patients received tamoxifen for > or = 2 years. Adjuvant chemotherapy was administered in 22% (n = 71) of patients. Groups 1 and 2 were not strictly comparable. Group 1 patients were significantly younger, had smaller tumors, were treated with cobalt at 5 x 2 Gy per week and axillary dissection was more frequently performed. Group 2 patients were more frequently bifocal and more frequently treated by quadrantectomy and tamoxifen, and irradiation used accelerator photons at 4 x 2.50 Gy per week. No difference in terms of follow-up and survival rates was observed between the two groups. For all patients the 5- and 10-year local breast relapse rates were 6.7% and 11%, respectively. No difference was observed regarding local control either by the electron or the iridium-192 implant boosts. Axillary dissection and age had an impact on the breast cosmetic outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Treatment of carcinoma of the penis by iridium 192 wire implant.

Since 1971, a group of 22 adult patients with squamous cell carcinoma of the penis have been treated by iridium 192 wires implant. There were 6 T1 tumors, 14 T2 tumors and 2 T3; only one patient (T3) presented with local failure after implant. Local necrosis occurred in 2 patients without local tumoral recurrence, but was sufficient enough to warrant amputation. Thus 19/22 (86%) patients were locally cured with penile conservation. In these patients the most frequent post-therapeutic complication is chronic urethral stenosis (9/19 patients, 47%) requiring repeated instrumental dilations. Four patients presented with initial inguinal metastatic nodes; only one was cured by radiosurgical treatment. Among patients without metastatic nodes at the time of diagnosis, none had delayed metastatic nodes. Three patients died of nodal evolution, 5 patients died of intercurrent disease without evidence of disease and 14 are now alive and NED. It appears that iridium 192 wires implant is the most effective conservative treatment of invasive squamous cell carcinoma of the penis; however, these results confirm that no particular treatment is required for inguinal nodal areas for patients who initially present with no disease.

Adult↗
PubMed1984

Interstitial radiation therapy for carcinoma of the penis using iridium 192 wires: the Henri Mondor experience (1970-1979).

From 1970 to 1979, a group of 50 patients was treated for squamous cell carcinoma of the penis by interstitial irradiation using an afterloading technique and iridium 192 wires. The group included 9 patients with T1 tumors, 27 with T2 tumors, and 14 with T3 tumors. Forty-five patients presented with no metastatic inguinal nodes (N0), 3 patients with N1 nodes, and 2 patients had N3 nodes. After treatment, 11 patients (1 T1, 6 T2 and 4T3) developed local recurrences; 10 of these 11 patients underwent penile amputation which controlled the tumor in 7 of the patients. One patient refused amputation. Three patients developed post-therapeutic necrosis which necessitated partial amputation in 2 cases. Eight patients developed post-therapeutic urethral stenosis, which required surgical treatment in three of the cases. Overall, at their last follow-up examinations, 74% of the patients were free of disease with conservation of penile morphology and function. Most patients without metastatic nodes (37/45) at diagnosis did not receive prophylatic treatment of the groin. Two of these patients developed delayed metastatic nodes; one was successfully salvaged. All 5 patients presenting with metastatic nodes at diagnosis died, four with uncontrolled regional disease. Twenty-one percent of the patients died of their disease. We advocate interstitial irradiation using iridium 192 wires for the treatment of non-infiltrating or moderately infiltrating squamous cell carcinoma of the penis in which the largest dimension does not exceed 4 cm. Pre-implant circumcision and regular long-term follow-up are necessary. More extensive tumors are better managed surgically. When regular follow-up can be assured, it is reasonable to forgo prophylactic treatment of the inguinal nodes in patients presenting without groin metastasis.

Adult↗
PubMed1985

Comparative dosimetry between iridium wires and seed ribbons.

We have undertaken a computer study that explores the conditions under which seed ribbons may replace iridium 192 wires in the Paris System. Compared with continuous iridium 192 wires, seed ribbons demonstrate greater inhomogeneity and loss of flexibility, simplicity, and other advantages. Nonetheless, we have defined the conditions where seed ribbons may be used in the Paris System to give satisfactory dose distributions and acceptable levels of heterogeneity within any given implant volume. These conditions include seed length, spacing between seeds, number of seeds per ribbon, and geometric arrangement of ribbons.

Brachytherapy↗
PubMed1986

A surface mold using iridium-192 seeds.

A radioactive mold for treating skin was constructed by embedding ribbons of iridium-192 seeds in bolus material. The mold was designed to match the treatment area outlined on the patient's skin. Computer-assisted pre-planning was performed to optimize the seed strength, number of seeds, and spacing of ribbons. An outline of the treatment area was transferred to the surface of a uniform slab of tissue-equivalent bolus material 1.3 to 1.4 cm thick and planned locations for the ribbons were marked. Seeds were loaded into the bolus material at a depth to place the sources approximately 1.0 cm from the skin. The resulting mold was flexible enough to conform to the patient's skin and the seeds were so tightly confined within the bolus that there was no possibility of loss. Isodose distributions for the mold on a flat surface agreed well with preplans. A velcro strap and neck collar were used to attach the mold to the anterior portion of the patient's neck. For situations in which radioactive surface applicators are desirable, the use of iridium-192 seeds offers uniform dose within a highly individualized treatment area.

Brachytherapy↗
PubMed1986

Radiation therapy for carcinoma of the pinna using iridium 192 wires: a series of 70 patients.

From January 1970 to November 1982, 70 patients with carcinoma of the pinna were treated by interstitial irradiation. An afterloading technique with Iridium 192 wires was used. One patient recurred and had a total pinnectomy followed by 60 Gy external radiation. This patient was alive without evidence of disease at 134 months. Three patients who had tumors greater than 4 cm in size at presentation developed late necrosis which required subsequent total pinnectomy. Cosmetic results were assessed in 55 patients and were good with few late sequelae (in 78% of cases (36/46) when the tumor measured less than 4 cm, but only in 1/9 when the tumor measured more than 4 cm). We advocate interstitial Iridium 192 irradiation for treatment of pinna tumors smaller than 4 cm. None of 39 patients with squamous cell carcinoma had biopsy proven cervical lymph node metastasis at the time of diagnosis. Four patients with squamous cell carcinoma (4/39: 10%) later developed a regional nodal metastasis after treatment of the pinna. All four relapsed in the parotid region and were managed by partial parotidectomy and neck dissection followed by external irradiation. One of these four patients died from uncontrolled cervical node disease. In our opinion, when regular follow-up is dependable, it is reasonable to save treatment of the cervical nodes for those patients who relapse with involved metastatic cervical nodes.

Adult↗