MEDICAL RESPONSE TO A RADIOLOGICAL ACCIDENT INVOLVING AN IRIDIUM-192 SOURCE IN NANJING, CHINA

On 7 May 2014, a radiological accident involving a lost 192Ir source occurred in Nanjing, China, and overexposure of a worker occurred. After the accident, several national agencies specialized in medical response to radiation emergencies collaborated to carry out clinical case management and to offer psychological assistance to the affected workers and members of the public. In this article, the medical management of the victim is summarized and outcomes are shared in order to improve medical preparedness and response for a nuclear or radiological emergency. This case demonstrated that providing rapid, accurate, credible and consistent information to the public through the media, public health education and psychological assistance to the affected workers and members of the public, contribute to mitigation of psychological impact of such emergencies.

[Complications and effectiveness of treatment of patients with locally advanced prostate cancer after combined radiotherapy and radical prostatectomy with postoperative radiotherapy]

Treatment for prostate cancer remains a significant social problem due to the continuing trend of growth of morbidity and mortality in Russia from this disease. In recent years a real alternative to surgical treatment is radiotherapy. In treatment of locally advanced stages of prostate cancer radiotherapy plays a dominant role. At our institution from 2005 till 2011, 105 patients with locally advanced prostate cancer underwent complex and combined treatment comprising in the first group the concomitant radiotherapy with Ir-192 and the control group--radical prostatectomy followed by adjuvant remote radiotherapy. In patients treated with concomitant radiotherapy compared to the control group there were occurred fewer number of genitourinary complications according to the RTOG scale (5,8% vs. 32,7%). In patients who had undergone radical prostatectomy followed by adjuvant radiotherapy urinary incontinence was met significantly often.

Shielding effect of a customized intraoral mold including lead material in high-dose-rate 192-Ir brachytherapy for oral cavity cancer

A high-dose-rate (HDR) 192-Ir brachytherapy using a customized intraoral mold is effective for superficial oral cavity cancer, and the surrounding normal tissue is kept away from the radioactive source with gauze pads and/or mouth piece for reducing the dose on the normal tissues. In the Tokushima university hospital, the mold has a lead shield which utilizes the space prepared with sufficient border-molding by a specific dental technique using modeling compound. In HDR 192-Ir brachytherapy using a lead shielded customized intraoral mold, there are no reports measuring the absorbed dose. The purpose of the present study is to measure the absorbed dose and discuss the optimum thickness of lead in HDR 192-Ir brachytherapy using a customized intraoral mold with lead shield using a 1 cm thickness mimic mold. The thickness of lead in the mold could be changed by varying the arrangement of 0.1 cm thickness sheet of the acrylic resin plate and lead. The measured doses at the lateral surface of the mold with thermo-luminescence dosimeter were reduced to 1.12, 0.79, 0.57, 0.41, 0.31, 0.24 and 0.19 Gy and the ratios to the prescription dose were reduced to 56, 40, 29, 21, 16, 12 and 10 percent as lead thickness increased from 0 to 0.6 cm in 0.1 cm increments, respectively. A 0.3 cm thickness lead was considered to be required for a 1 cm thickness mold, and it was necessary to thicken the lead as much as possible with the constraint of limited space in the oral cavity, especially at the fornix vestibule.

An update on three radiation accidents in South America

This paper revisits three major accidents that occurred in South America. The main purpose of this review is to analyze the long term health and other effects of accidental exposures to ionizing radiation in order to extract lessons from these radiological emergencies that might be useful for avoiding similar events (primary prevention) and for preparing the overall response to radiation accidents to mitigate their different impacts (secondary prevention). For that, consults were made on the pertinent literature and use was made of personal information of the authors.

CT-based 3D dose-volume parameter of the rectum and late rectal complication in patients with cervical cancer treated with high-dose-rate intracavitary brachytherapy

This study evaluated the efficacy of computed tomography (CT)-based three-dimensional (3D) dose-volume parameters of the rectum as predictor for late rectal complication (LRC) in cervical cancer patients treated with radiotherapy alone. Eighty-four patients treated with a combination of external radiotherapy and high-dose-rate intracavitary brachytherapy between January 2000 and December 2004 were retrospectively analyzed. Brachytherapy was prescribed with standard 2D planning. Patients underwent pelvic CT at brachytherapy. The external rectal wall was contoured on the CT images, and the minimum doses delivered to 0.1cc, 1cc, and 2cc of the most irradiated rectal volumes were calculated with dose-volume histograms. The International Commission of Radiation Units and Measurements (ICRU) rectal point dose was also calculated by conventional method. Total dose (external radiotherapy plus brachytherapy) to the rectum was transformed to the biologically equivalent dose in 2-Gy fractions with alpha/beta of 3 Gy (D(0.1cc), D(1cc), D(2cc) and D(ICRU)). The relationships between these dosimetric parameters and the incidence of LRC were analyzed. The 5-year overall actuarial rate of LRC was 26.4%. The values of D(0.1cc), D(1cc), and D(2cc) were significantly higher in patients with LRC than in those without (p < 0.001), but the difference in the values of D(ICRU) was not statistically significant (p = 0.10). The rate of LRC increased significantly with increasing D(0.1cc), D(1cc), and D(2cc) (p = 0.001). However, no positive dose-response relationship was observed between D(ICRU) and the rate of LRC (p = 0.42). The present study has suggested that CT-based 3D dose-volume parameters of the rectum may be effective for predicting LRC.

Lack of the dose-rate effect of 192Ir source activity on pelvic control and late complications after high-dose-rate brachytherapy for cervical cancer

This study aimed to assess the dose-rate effect of (192)Ir source activity on pelvic control and late complications following high-dose-rate intracavitary brachytherapy (HDRICB) for cervical cancer patients. Two hundred and twelve patients were enrolled in this study. They were treated with external beam radiotherapy to the pelvis, after which HDRICB was performed using (192)Ir remote after-loading at 1-week intervals for 4 or 5 sessions. Source activity was defined as the average of source activity in each HDRICB session. Dose-rate effect was analyzed after stratification of stage and biologically effective dose (BED). The 5-year pelvic relapse-free survival was 88% for all patients. Forty-two patients developed late rectal complications (13 grade 1, 23 grade 2, 6 grade 3-4). Twenty-seven patients had grade 2 and higher late bladder complications (14 grade 2, 13 grade 3-4). There was no dose-rate effect on pelvic control or complications when source activity was stratified. Multivariate analysis demonstrated a high risk of grade 2 and higher rectal sequelae in patients whose rectal BED >or= 110 Gy(3) (p = 0.039, hazard ratio 2.05). The high risk factors for grade 2 and higher bladder complications were a bladder BED >or= 100 Gy(3) (p = 0.03, hazard ratio 4.37). This study demonstrated no dose-rate effect of (192)Ir source in HDRICB for cervical cancer in terms of pelvic control or radiation injuries. Careful monitoring of the BED values for rectum and bladder is a scrutinizing factor for minimizing late sequelae.

Case report: Iridium 192-health effects during 20 years after irradiation

This Case Report has presented health effects of high level of irradiation with gamma rays from Ir 192m on the patient M. L. during 21 years after the accident. The main purpose of this investigation was to analyze long time consequences of partial high-level irradiation on human health. Locally, short-term irradiation, with high deadly dose, caused acute radiation syndrome with reversible disorder function of the individual, most exposed, organs. Frequency of chromosomal aberrations (dicentric), characteristic for direct irradiation, was increased. However, dicentric analyzes did not give expected result for an acute radioactivity illness. Radio dermatitis had begun already after the incident, while changes on the heart began not earlier than six months and gradually have been increased up to two years after the incident. Irradiated parts of the patient skin have been replaced with auto-transplanted skin and appropriate therapy had been taken. More than two decades after the irradiation, system (leukemia) nor solitary tumor on near organs (liver, heart, lungs, bones) have not been appeared. Radiation illness did not happen in spite of very large dose, because impacts had been local and body was unlikely irradiated. Also, an appropriate therapy was organized and other potential illnesses did not appear.

Stable and unstable chromosome aberrations measured after occupational exposure to ionizing radiation and ultrasound

AIM

To evaluate chromosome aberration and fluorescent in situ hybridization (FISH) assays as a method to estimate of health risk, we monitored 9 male subjects occupationally exposed to low doses of both ionizing radiation and ultrasound during a period of over 3 years.

METHODS

Sampling was performed at 6-month intervals during a three-year period. First we used conventional chromosomal aberrations analysis. When the aberration frequency for a particular subject reached the background, we measured translocations in the final sample, using fluorescence in situ hybridization. Chromosome painting probes for chromosomes 1, 2, and 4 were used simultaneously.

RESULTS

Dicentric and ring chromosomes were eliminated within a year. Translocations persisted and deviated from control values in all examinees. Translocations were detected long after unstable aberrations decreased to the background level.

CONCLUSION

Fluorescence in situ hybridization-based translocation detection was a reliable method for monitoring chronic occupational clastogen exposure. Chromosome aberration assay correlated with translocation frequency. Stable chromosomal aberrations reflected cumulative genome damage during job exposure.

High Dose Rate Iridium-192 Brachytherapy as a Component of Radical Radiotherapy for the Treatment of Localised Prostate Cancer

AIMS

To assess the treatment outcomes and toxicity of conformal high dose rate (HDR) brachytherapy boost as a means of radiation dose escalation in patients with localised prostate cancer.

MATERIALS AND METHODS

Between December 1998 and July 2004, 65 consecutive patients with localised prostate cancer (magnetic resonance imaging-staged T1-3 N0 M0) were treated with external beam radiation therapy (EBRT) followed by two fractions of HDR iridium-192 brachytherapy. The patients selected this treatment modality in preference to entering an ongoing randomised phase 3 trial. Any pre-treatment serum prostate-specific antigen (PSA) and Gleason score were included. The primary end point was biochemical disease-free progression. Late treatment-related morbidity was graded according to the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer criteria.

RESULTS

The median patient age was 67.3 years (range 47.9-80). Sixty patients (92.3%) had intermediate- to high-risk disease defined by clinical stage, presenting PSA and Gleason score/World Health Organisation (WHO) grade. With a median follow-up of 3.5 years (range 0.6-5.8), two patients had died of metastatic disease and another four patients had PSA relapse, giving a 3-year actuarial biochemical disease-free progression of 90.8%. Three patients (4.6%) had acute grade 3 genitourinary toxicity, in the form of urinary retention. Late grade 3 and 4 genitourinary toxicities occurred in four patients (6.2%) and one patient (1.5%), respectively. No late gastrointestinal toxicities were observed.

CONCLUSIONS

These results suggest that the combined modality of conformal HDR brachytherapy and EBRT is a feasible treatment modality with acceptable acute and late toxicities, comparable with those of EBRT alone. It offers an attractive conformal treatment modality with the potential of further dose escalation in the treatment of localised prostate cancer.

Preliminary results of mitomycin C local application as post-treatment prevention of vaginal radiation-induced morbidity in women with cervical cancer

PURPOSE

To determine the usefulness of local mitomycin C application in the prophylaxis of vaginal narrowing after irradiation.

MATERIAL AND METHODS

31 patients with advanced cervical cancer qualified for the study. They underwent brachytherapy with iridium-192 isotope and external beam therapy with linear accelerators. In a blind probe method 16 patients were chosen to have an aqueous solution of mitomycin C applied to the vagina.

RESULTS

Radiotherapy caused a shortening of vaginal length in both groups (study and control). In the "mitomycin C group" complete vaginal occlusion was visibly less frequent as were solid fibrotic vault changes.

CONCLUSIONS

This mode of morbidity prevention can potentially diminish the occurrence of local vaginal fibrosis and thus may improve patients' quality of life. Further investigations are needed to confirm these results.

Effective dose for patients undergoing coronary and femoral intravascular radiotherapy involving an HDR 192Ir source

Effective dose equivalent (EDE), and effective dose (ED) for coronary and femoral Intravascular brachytherapy (IVBT) procedures involving a 370 GBq (10 Ci) HDR 192Ir gamma source are tabulated. MIRD stylised models and the MCNP Monte Carlo code were used for the calculations. For coronary irradiation, the normalised EDE is 0.18 mSv (GBq min)(-1) and the ED is 0.056 mSv (GBq min)(-1). For femoral IVBT, the normalised EDE is 0.01629 mSv (GBq min)(-1) and the ED is 0.01195 mSv (GBq min)(-1). Although the medical benefits to a patient undergoing IVBT are often significant and justified, patient doses are high compared with dose limits for radiation protection purposes. As IVBT is becoming a routine procedure, data in this paper could be useful to manage the procedures efficiently.

Acute complications of MammoSite brachytherapy: A single institution's initial clinical experience

PURPOSE

To report the acute complications incurred by the initial 37 patients who underwent accelerated partial breast irradiation with the MammoSite balloon breast brachytherapy applicator at the Medical University of South Carolina.

METHODS AND MATERIALS

Between May 2002 and March 2003, 37 patients with ductal carcinoma in situ or invasive carcinoma had MammoSite brachytherapy catheters successfully place after lumpectomy by one of four surgeons and were deemed eligible for high-dose-rate brachytherapy. An open technique was used in 32 implants and the scar entry technique was used in 5 implants. Patients had Stage pTis-pT2N1 with negative margins. A dose of 34 Gy was prescribed to 1 cm from the balloon surface using (192)Ir high-dose-rate brachytherapy and was delivered in 10 fractions twice daily. CT was used to confirm that the balloon surface was adherent to the lumpectomy cavity and to measure the balloon surface to skin surface distance. CT images and daily fluoroscopic simulations were used for treatment planning. Patients were assessed for acute toxicity on the day of therapy completion and 4 weeks after therapy by the radiation oncologist. In addition, all available data from radiation, surgical, and medical oncology were retrospectively reviewed for documentation of complications. All patients in this series had a minimal follow-up of 3 months; the mean follow-up for all patients was 7 months.

RESULTS

The acute complications were categorized as operative wound complications, infections, skin toxicity, seromas, or catheter failures. Operative wound complications occurred in 3 patients (8%). Radiation Therapy Oncology Group Grade 2 and Grade 3 toxicity occurred in 2 (5.4%) and 1 (2.7%) patient, respectively. Six (16.2%) developed wound infections and 12 (32.4%) seromas. Catheter failures due to leak occurred in 2 patients (5.4%) and rupture in 3 (8%).

CONCLUSION

The types of complications in this experience were similar to those in the Phase I trial of the MammoSite brachytherapy applicator. However, catheter failure due to leak occurred in our experience and was not described in the Phase I trial. The incidence of complications was greater in our series than in the Phase I trial; however, differences in toxicity scoring and the length of follow-up between the two series impeded direct comparisons. The incidences of complications over time reflect the steep learning curve for accelerated partial breast irradiation using the MammoSite brachytherapy applicator. Finally, radiation recall dermatitis developed in 1 patient treated after this review was completed.

High-dose-rate iridium-192 afterloading therapy combined with external beam radiotherapy for T1c-T3bN0M0 prostate cancer

OBJECTIVES

To determine the efficacy of radiotherapy (RT) for T1c-T3bN0M0 prostate cancer in a prospective clinical trial of concurrent external beam RT and fractionated iridium-192 high-dose-rate brachytherapy.

METHODS

Included in the study were 98 patients with T1c-T3bN0M0 prostate cancer who were diagnosed between October 1997 and September 2002 and underwent high-dose-rate brachytherapy with external beam RT. Treatment consisted of external beam RT (four ports) to the prostate of 16 fractions of 2.3 Gy to a total dose of 36.8 Gy and high-dose-rate brachytherapy of 4 fractions of 6.0 Gy within 30 hours to a total dose of 24.0 Gy. No patient received adjuvant hormonal therapy after RT.

RESULTS

The most recent prostate-specific antigen level was 0.0 to 3.9 ng/mL (median 0.4). Seven patients (7.1%) developed recurrence and treatment was considered a failure (bone metastasis in two and biochemical failure in five). The overall biochemical disease-free survival (bDFS) rate was 95.9% at 2 years and 92.9% at 5 years. The bDFS rate by T stage was 98.6% at 2 years and 95.9% at 5 years for Stage T1c-T2b and 88.0% and 84.0% for Stage T3a-b, respectively (P = 0.047). The 2-year and 5-year bDFS rate was better in patients with an initial prostate-specific antigen level of less than 20 ng/mL compared with 20 ng/mL or greater (98.6% and 97.1% versus 93.1% and 82.8%, respectively, P = 0.0261). Acute toxicity was mild to moderate (Radiation Therapy Oncology Group grade 1-2) and consisted of cystourethritis or proctitis in 29 (29.6%) of 98 patients.

CONCLUSIONS

With a low complication rate and satisfactory bDFS rates, this combination therapy can be considered an alternative method for clinical Stage T1c-T3b prostate cancer and is expected to improve patient quality of life. Additional long-term follow-up is needed to confirm this treatment.

Iridium-192 Interstitial Brachytherapy as Adjunctive Treatment for Canine Cutaneous Mast Cell Tumors

Eleven dogs with cutaneous mast cell tumors (MCTs) were treated with surgery and iridium-192 (192Ir) interstitial brachytherapy. Minimum tumor doses ranged from 47.2 to 63.3 Gy. Treated tumors were classified as grade II (n=7) or III (n=4). Five dogs had recurrences with a median progression-free interval of 1391 days, and six dogs had no recurrence at a median follow-up time of 942 days. Acute adverse effects were well tolerated, and late effects were mild. One dog developed a second tumor of a different cell type in the radiation treatment field.

Eyelid and scleral necrosis following bare iridium-192 seed for retinoblastoma

A 2 1/2-year-old girl with a history of bilateral retinoblastoma underwent primary enucleation of the right eye and was referred for further management of persistent tumor in the fellow eye. Previous treatment of the left eye included external beam radiotherapy, systemic chemotherapy, laser photocoagulation, cryotherapy, and direct scleral application of a bare iridium-192 radioactive seed. Examination revealed focal full-thickness necrosis of the left upper and lower eyelid and a large inferonasal viable retinoblastoma tumor with overlying retinal detachment. Systemic chemotherapy and direct laser photocoagulation were administered. Four months after presentation, the patient developed focal scleral necrosis with 360 degrees hemorrhagic choroidal detachment. Enucleation was performed and histopathologic examination demonstrated full-thickness scleral necrosis with adjacent viable retinoblastoma tumor cells. Follow-up examinations showed no evidence of recurrent or metastatic tumor. This case is the first report of scleral necrosis following combined modality treatment of retinoblastoma.

Iridium-192 implantation for T1 and T2a carcinoma of the tongue and floor of mouth: retrospective study of the results of treatment at the Royal Berkshire Hospital

Carcinomas of the tongue and floor of mouth are relatively rare tumours, which may be treated using several modalities. We reviewed the results of iridium wire implants performed at the Royal Berkshire Hospital between 1994 and 2000. 24 patients had iridium wire implants as primary treatment for tongue and floor of mouth cancers. Four patients were treated after excision biopsy with close or involved margins. One patient was treated for a recurrence after surgery. The median age at treatment was 61 years. There were 18 men and 11 women. 21 patients had tumours of the tongue and eight of the floor of mouth. 13 had T1 tumours and 11 had T2a tumours. The median follow up was 42 months. The primary tumour was controlled in 22 of the 29 patients by the implant alone. Of the seven patients with local recurrence four were successfully salvaged with surgery. The acturarial 2 year survival rates were: overall survival 81%, disease specific survival 91%, local recurrence free survival 85% and nodal relapse free survival 76%. The recorded complication rate was low, one patient developing radionecrosis of the mandible at 7 years post implant. We believe these results show that brachytherapy remains a treatment option for patients with early tongue carcinoma with a high rate of local control and low toxicity.

Antioxidants attenuate atherosclerotic plaque development in a balloon-denuded and -radiated hypercholesterolemic rabbit

BACKGROUND

Oxidation of lipoproteins is considered to be a key contributor to atherogenesis. Antioxidants are potential antiatherogenic agents because they can inhibit lipoprotein oxidation. Radiation has been shown to increase oxidative stress leading to increased atherogenesis. This study is designed to test the potential of antioxidants to inhibit atherosclerotic plaque progression in balloon-denuded and -radiated rabbits.

METHODS AND RESULTS

Two groups of New Zealand white rabbits (n=36) were fed with 1% cholesterol diet (control diet) or with 1% cholesterol diet containing a mixture of various antioxidants for 1 week. Iliac arteries in all the animals were balloon denuded and continued to fed with 0.15% cholesterol diet or 0.15% cholesterol diet containing antioxidants (antioxidant diet). Four weeks after balloon denudation one iliac artery in 12 animals from each group was radiated and all the animals were continued to be fed with the same diet. Four weeks after radiation animals were sacrificed and morphometric analysis of iliac arteries (n=12) in nonradiated and radiated animals were performed. Plaque area (PA) in the rabbits that were fed with cholesterol diet is 0.2+/-0.12 mm2, and it is increased by 2.75-fold (P<.05) in the radiated arteries of animals fed with cholesterol diet. Plaque area in the animals fed with antioxidant diet is 50% less then the one in the animals fed with cholesterol diet. Similarly, plaque area in radiated arteries of the animals fed with antioxidant diet is 50% less then the animals fed with cholesterol diet.

CONCLUSION

Antioxidants significantly attenuate atherosclerotic plaque progression in balloon-injured and -radiated hypercholesterolemic rabbits.

[Accidents in radiotherapy: historical account]

Radiotherapy accidents are exceedingly rare. However, they may have major negative consequences: for health (and sometimes life) of victims as well as for the trust that patients put in radiotherapy and radiation oncologists. Each accident must be pointed out, analysed and reported, in order to allow preventive actions, avoiding repetitive accidents. Through examples of majors accidents occurred all over the world in the last decades, affecting professionals, public or patients themselves, the necessity of transparency is demonstrated. The International Commission of Radiobiological Protection has drawn positive lessons from such accidents and insists on following recommendations: necessity of sufficient number and competent professionals, importance of continuous and initial education, information of professionals and, in general, a strict Quality Assurance program. It is clear that each radiotherapy center remains at risk for errors. It is essential to develop preventive procedures to avoid transformation of errors into accidents. In that context, complete and detailed description and reports of each anomaly or incident must be encouraged as it is done for sectors of aviation or nuclear industry. Radiation oncology must develop such a culture of transparency and of systematic report of all incidents.

Long-term outcome of patients treated with repeat percutaneous coronary intervention after failure of gamma-brachytherapy for the treatment of in-stent restenosis

BACKGROUND

Although (192)Ir intracoronary brachytherapy has been demonstrated to dramatically reduce the recurrence of in-stent restenosis, up to 24% of these patients will still require repeat target-vessel revascularization. The short- and long-term outcomes of repeat percutaneous intervention in this population have not been characterized.

METHODS AND RESULTS

Analysis was performed of all patients enrolled in the GAMMA-I and GAMMA-II brachytherapy trials who underwent repeat percutaneous target lesion revascularization (TLR) because of restenosis. Subjects were divided into 2 cohorts: those who had received (192)Ir brachytherapy and those randomized to placebo. Forty-five (17.6%) of a total of 256 patients whose index treatment was intracoronary radiation therapy and 36 (29.8%) of 121 patients whose index treatment was placebo required repeat percutaneous TLR. The mean time to this first TLR was 295+/-206 days in the irradiated group and 202+/-167 days in the placebo group (P=0.03). Acute procedural success occurred in 100% of irradiated patients and 94% of placebo controls (P=0.19). After the first TLR, a subsequent TLR was required in 15 (33.3%) of 45 brachytherapy patients versus 17 (47.2%) of 36 placebo failure patients (P=0.26). There was no significant difference in time to second TLR between the 2 groups. Other long-term major adverse event rates in both groups were comparable to those of other contemporary angioplasty/stenting series.

CONCLUSIONS

In those patients who "fail" (192)Ir intracoronary brachytherapy for in-stent restenosis, treatment with (192)Ir delays the time to first TLR. Additionally, repeat percutaneous intervention in these patients is safe and efficacious in the short term, with acceptable long-term results.

Geographical miss during intracoronary irradiation: impact on restenosis and determination of required safety margin length

OBJECTIVE

The goal of this study was to evaluate the incidence and effects of underdosage of injured segments during intracoronary irradiation and to define the minimal length of safety margin required to avoid mismatched source placement.

BACKGROUND

Underdosage of injured segments due to misplacement of active source has been suggested as the underlying mechanism for the occurrence of edge restenosis.

METHODS

Baseline angiograms of 112 vessels in 109 patients with in-stent restenosis undergoing coronary reintervention followed by intracoronary irradiation ((192)Ir: Checkmate, Cordis, Miami, Florida; (32)P: Gallileo, Guidant, Houston, Texas; (90)Sr/Y: Beta-Cath, Novoste, Norcross, Georgia) were analyzed. The distances between the outermost injury and outermost end of "reference isodose length" (RIL), defined as a segment with >/=90% of reference dose at 1 mm vessel wall depth, were measured. "Safety margin" was defined as the distance between the outermost injury and outermost end of the RIL, "geographical miss" (GM) as a complete injured segment not being covered by the RIL, and "restenosis" as the percent diameter stenosis >50%.

RESULTS

Baseline angiographic analysis was performed for 224 edges in 112 vessels. Geographical miss was found in 46 (20.6%) edges. The incidence of target lesion restenosis within the 78 vessels with available follow-up was 43.3% for patients with GM versus 14.9% for patients with no GM (p = 0.005). Analysis of various injured segments exposed highest restenosis rates in injured segments with negligible irradiation (27.8%) in comparison with injured segments with dose fall-off (16.7%) or injured segments with full-dose irradiation (7.7%) (p = 0.006). Receiver operating curve analysis revealed a safety margin of 10 mm required per vessel (i.e., 5-mm safety margin/edge) to achieve 95% specificity of GM.

CONCLUSIONS

Geographical miss is associated with a higher incidence of restenosis at the corresponding edges. Restenosis was more pronounced in injured segments with negligible irradiation than in injured segments at the dose fall-off zones. We recommend a safety margin of 10 mm per vessel to minimize GM.

Cytogenic investigations of serious overexposures to an industrial gamma radiography source

This paper describes the sequence of events, medical aspects and dose estimations for two radiographers and their driver who were seriously exposed to an iridium-192 industrial radiography source that became detached from its wind-out cable. The men came to medical attention about 1 month later by which time all three were severely leucopenic and one had skin burns on both hands. Doses were estimated by (i) physics calculations combined with their accounts of the event. (ii) the levels of depression of their blood neutrophils, (iii) electron spin resonance on tooth enamel and (iv) blood lymphocyte chromosomal analyses by the conventional dicentric and the fluorescence in situ hybridisation methods. Intercomparison of these methods for estimating doses showed a good level of agreement. In brief, the averaged whole body dose for the most seriously exposed man was about 2.5-3.0 Gy and for the others it was 1.0-2.0 Gy.

Ytterbium-169: a promising new radionuclide for intravascular brachytherapy

PURPOSE

To explore the feasibility of 169Yb (gamma, 93 keV) as a new radionuclide for intravascular brachytherapy (IVBT) in terms of dose distribution, penetration power, and radiation safety features as compared with 125I and 192Ir.

METHODS

The dose distributions for catheter-based sources, 169Yb, 125I, and 192Ir, in homogeneous water and in the presence of calcium and a steel stent have been determined and compared using the Monte Carlo method (MCNP4B2 code). The dose rates of the sources were evaluated from 0.02 to 100 cm.

RESULTS

In the short distance range (0.02<r<1.0 cm), the dose distributions in homogeneous water are very similar for the three radionuclides when the dose rates are normalized at 2 mm. Between 1 and 20 cm, the relative dose rates fall off similarly for 169Yb and 192Ir, whereas for 125I, it decreases much more rapidly. At a distance further away (r approximately 100 cm), the dose rate of 169Yb is about 10 times lower than that of 192Ir, indicating the cathlab radiation shielding requirement for 169Yb is substantially reduced as compared with 192Ir. Calcified plaques and stents cause a drastic dose reduction in the arterial wall for 125I, but have no effect for 192Ir gamma-rays. Only slight dose reductions were detected for 169Yb beyond a layer of 1.0-mm calcium (2-3%), and behind a steel stent strut (5%).

CONCLUSION

169Yb is a promising new radionuclide for IVBT. It has a much better penetrating power through calcified plaques and stents compared with the low-energy source 125I. It also provides easier radiation protection measures for cardiac cathlab personnel than the high-energy source 192Ir, while preserving a favorable dose distribution in tissues surrounding an arterial vessel.

High-dose-rate endobronchial brachytherapy effectively palliates symptoms due to airway tumors: the 10-year M. D. Anderson cancer center experience

PURPOSE

To evaluate the toxicity and efficacy of Iridium-192 high-dose-rate (HDR) endobronchial brachytherapy (EBBT) for the palliation of symptoms caused by relapsed or persistent endobronchial tumors.

METHODS AND MATERIALS

We reviewed the treatment outcomes between 1988 and 1997 in 175 lung cancer patients who underwent HDR EBBT for recurrent or metastatic tumors at The University of Texas M. D. Anderson Cancer Center. One hundred sixty of these patients had previously received thoracic external-beam irradiation. This updated report includes 74 patients from a previous series. Most patients received 3,000-cGy EBBT delivered at a distance of 6 mm and divided into 2 fractions over 2 weeks. Subjective response was assessed by questionnaire at follow-up. Objective response was assessed by physical examination, bronchoscopy, and chest radiograph.

RESULTS

The median actuarial survival for the entire group was 6 months from the time of the first EBBT treatment session. Of the 115 patients (66%) who showed symptomatic improvement, 32% were much improved and 34% were slightly improved. Patients showing improvement survived for significantly longer than those who showed no change or worsening symptoms (7 vs. 4 months, p = 0.0032). Repeat bronchoscopy demonstrated a 78% overall objective response rate that correlated significantly with subjective response and symptom relief. Complications occurred in 19 patients (11% crude rate) with an actuarial complication rate of 13% at 1 year from the time of the first EBBT treatment session. The actuarial hazard for fatal hemoptysis due to EBBT was 5%.

CONCLUSION

HDR EBBT effectively palliates most patients' symptoms caused by endobronchial lesions. This relief correlates significantly with an overall survival benefit. Treatment complications appear to be few, even for patients who have received prior external-beam irradiation.

Radioactive plaque therapy for metastatic choroidal carcinoma

PURPOSE

To describe the outcome of radioactive episcleral plaque therapy for treatment of metastatic carcinoma to the choroid.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Five patients (six eyes) with carcinoma metastatic to the choroid.

METHODS

Retrospective review of the clinical records of five patients (six eyes) who underwent radioactive episcleral plaque therapy for choroidal metastases.

MAIN OUTCOME MEASURES

Tumor height, visual acuity, radiation optic neuropathy, and radiation retinopathy.

RESULTS

Radioactive episcleral plaque therapy resulted in shrinkage of the treated tumors and resolution of subretinal fluid in all eyes. After plaque treatment, best-corrected visual acuity was maintained within two lines of initial visual acuity for two eyes, decreased more than two lines for one eye, and improved more than two lines in three eyes. The treatment was well tolerated and there was no acute toxicity. Late complications included optic nerve atrophy (at 2 years) with proliferative radiation retinopathy (at 3 years) in one eye and optic atrophy (at 6 months) in another eye that had received prior external beam therapy.

CONCLUSIONS

In carefully selected cases, radioactive episcleral plaque therapy appears to be an effective and reasonable treatment for carcinoma metastatic to the choroid.

Single dose irradiation response of pig skin: a comparison of brachytherapy using a single, high dose rate iridium-192 stepping source with 200 kV X-rays

An experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell kinetics and radiation-induced responses are similar to human skin. Brachytherapy was performed using a microSelectron high dose rate (HDR) afterloading machine with a single stepping source and a custom-made template. In this study the acute epidermal reactions of erythema and moist desquamation and the late dermal reactions of dusky mauve erythema and necrosis were evaluated after single doses of irradiation over a follow-up period of 16 weeks. The major aims of this work were: (a) to compare the effects of iridium-192 (192Ir) irradiation with effects after X-irradiation; (b) to compare the skin reactions in Yorkshire and Large White pigs; and (c) to standardize the methodology. For 192Ir irradiation with 100% isodose at the skin surface, the 95% isodose was estimated at the basal membrane, while the 80% isodose covered the dermal fat layers. After HDR 192Ir irradiation of Yorkshire pig skin the ED50 values (95% isodose) for moderate/severe erythema and moist desquamation were 24.8 Gy and 31.9 Gy, respectively. The associated mean latent period (+/- SD) was 39 +/- 7 days for both skin reactions. Late skin responses of dusky mauve erythema and dermal necrosis were characterized by ED50 values (80% isodose) of 16.3 Gy and 19.5 Gy, with latent periods of 58 +/- 7 days and 76 +/- 12 days, respectively. After X-irradiation, the incidence of the various skin reactions and their latent periods were similar. Acute and late reactions were well separated in time. The occurrence of skin reactions and the incidence of effects were comparable in Yorkshire and Large White pigs for both X-irradiation and HDR 192Ir brachytherapy. This pig skin model is feasible for future studies on clinically relevant multifractionation schedules in a brachytherapy setting.

Feasibility study combining low dose rate (192)Ir brachytherapy and external beam radiotherapy aiming at delivering 80-85 Gy to prostatic adenocarcinoma

BACKGROUND

Increasing the radiation dose to prostatic adenocarcinoma has provided higher local control rates. A total of 80 Gy seem necessary to achieve this goal but patient set-up and prostate motion remain difficult problems to solve in conformal radiotherapy. Brachytherapy which overcomes these points could be an alternative way to external beam boost fields. We wanted to transpose the irradiation models largely used in cervix cancer treatment combining external beam radiotherapy and low dose rate brachytherapy.

MATERIALS AND METHODS

In 71 patients with 19.5 and 13 ng/ml mean and median PSA levels, respectively, a dose escalation from 74 to 85 Gy was performed in four groups.

RESULTS

Shifting from intraoperative placement of sources vectors (Group I) to positioning under ultrasound controls (groups II-IV), improving the implantation shape and optimizing radiation delivery to urethral bed have reduced the total dose to rectal wall under 65 Gy and to urethra under 100 Gy. Rectal/prostate dose ratio was lowered from 0.7 (Groups I-II) to 0.58 (Groups III-IV) while avoiding problems resulting from pelvic bone arch interference, prostate volume or seminal vesicles location. The mean and median follow-up periods are 28 and 18 months. In Groups III and IV 85% of patients without hormonotherapy treated with 80-85 Gy normalized PSA under 1 ng/ml within 6 months. No severe late effect has been noted for patients implanted under echographic control.

CONCLUSIONS

The method described allows to deliver 85 Gy. Longer follow-up is however needed but the levels of dose delivered are not expected to induce prohibitive side effects.

Interstitial iridium-192 implantation for recurrent and/or locally advanced head and neck cancer

We report our experience with the use of interstitial iridium-192 implantation in the management of patients with recurrent and locally advanced squamous cell carcinoma of the head and neck. Between June 1992 and July 1998 this technique was employed in the management of two groups of patients: (1) a primary group, comprising 42 patients who had presented for the first time with advanced head and neck disease, and had therefore not undergone any previous treatment; and (2) a salvage group of 16 patients with recurrent disease previously treated with external beam radiotherapy (four received therapy to the neck, one to the cheek, eight to the tongue and three to the floor of the mouth). The follow-up in each group was short, ranging from 3 to 56 months. The overall response in the primary group was 38/42 (90%). A complete response was achieved in 35/42 (83%). In the salvage group, the overall response was 13/16 (81%); 4/16 (25%) showed a complete response and 9/16 (56%) a partial response. The estimated percentage surviving at 1 year for patients with primary disease is 70% (95% confidence interval (CI) 54-86). For those receiving salvage therapy the estimated percentage surviving at 1 year is 45% (95% CI 19-71).

[Combined treatment of localized prostate cancer with HDR-Iridium 192 remote brachytherapy and external beam irradiation]

BACKGROUND

The localized prostate cancer can be treated curatively by radiation therapy. The combined treatment of external beam irradiation and HDR-Iridium 192 remote brachytherapy allows higher radiation doses within the tumor without increasing radiation sequelae.

PATIENTS AND METHODS

Patients of our clinic have been treated with this combined procedure since 1991. Between 1991 and 1994 15 patients received 2 x 9 Gy of high-dose-rate brachytherapy, followed by 36 Gy external beam irradiation (group A). Because of the frequent local failures in group A, the reference dose of external beam irradiation was increased to 50.4 Gy after brachytherapy between 1994 and 1996.

RESULTS

Seven of 15 patients (47%) in group A developed a local recurrence after a median of 17 (13 to 30) months. In group B (20 patients) local failure occurred in 3 patients (15%) after 11, 16 and 32 months.

CONCLUSION

The combined radiation therapy of localized prostate cancer cannot substitute radical prostatectomy completely, but it is a promising alternative in the curative treatment in selected patients.

A lost pigtail

Images

[Interstitial brachytherapy in infiltrating cancer of the bladder. The Nancy experience]

PURPOSE

From 1975 to 1996, 98 patients with infiltrative vesical carcinomas were treated at the Centre Alexis Vautrin by conservative surgery and interstitial brachytherapy (192lr). The mean follow-up was about eight years. From this retrospective non randomized study, we tried to determine the tolerance to this treatment.

MATERIALS AND METHODS

There were 86 men and 12 women. The mean age was 63 years. We found three pTis tumors, 28 stage pT1 tumors, 38 stage pT2 tumors, 24 stage pT3A tumors, four stage pT3B tumors and one stage Tx tumors. The therapeutic scheme consisted of pelvic radiation therapy (3 fractions of 3,5 Gy) immediately followed by lymphadenectomy (for stage pT3 tumors) and by cystotomy or partial cystectomy during which we inserted brachytherapy plastic tubes. The delivered dose was 50 Gy for superficially infiltrative tumors and 30 Gy for deeply infiltrative tumors; at the lowest dose, the treatment ended with external beam irradiation.

RESULTS

At 5 years the control rate was 72%, the specific survival 80% and the global survival 71%. Twenty-nine patients had a local recurrence. Of these, seven underwent total cystectomy. Thirty-seven patients developed 43 complications; 35 were intravesical, 10 (28%) were estimated to be higher than grade 2 because of technical problems that led us to modify the technique.

CONCLUSION

It is essential to develop close collaboration between surgeons and brachytherapists, to select patients and to use a rigorous technique. Interstitial brachytherapy for infiltrative vesical carcinomas thus yields both high local control and satisfying results in regard to patient's well-being.

An examination of radiation exposure to clinical staff from patients implanted with 137Cs and 192Ir for the treatment of gynecologic malignancies

The treatment of cancers by placement of radioactive materials within or adjacent to a tumor is clinically known as brachytherapy. Although the intracavitary treatment of gynecologic cancers using 137Cs has been in widespread use for nearly a century, interstitial techniques using 192Ir have developed within the last decade. Both procedures are performed as temporary implants and typically require a hospital stay of approximately 48 h. Significant differences in source strengths, loading conditions, and patient care requirements are visible between the intracavitary and interstitial techniques. Facilities that are experienced in the use of intracavitary techniques may lack clinical experience in the use of newer interstitial procedures. An examination of radiation exposure to the radiation oncology staff administering the treatment, exposure rate at frequently occupied points in the patient room, and exposure to the nursing staff will be of value to those institutions considering integration of interstitial brachytherapy techniques into their department.

Outcome of treatment of upper third vaginal recurrences of cervical and endometrial carcinomas with interstitial brachytherapy

PURPOSE

To describe an original brachytherapy technique using a dedicated intravaginal template for the treatment of vaginal vault recurrences and to evaluate the results of such a treatment.

METHODS AND MATERIALS

Between 1978 and 1993, 78 patients with isolated recurrence of cervical or endometrial carcinoma located in the vaginal vault have been treated in Lyon. Initial treatment was surgery alone in 49 cases and irradiation with surgery in 37 cases. Treatment of the vaginal recurrence was performed with interstitial Iridium 192 brachytherapy combined with pelvic external beam radiation therapy in 34 patients. The tumor was implanted with a dedicated intravaginal plastic template. Six parallel metallic needles were implanted in the vaginal vault and afterloaded with Iridium 192 wires of 4 to 6 cm long. The mucosa of the upper half of the vagina received the same dose as the one encompassing the tumor on the 85% isodose of the Paris system.

RESULTS

At 5 years the local control rate was 70% and the overall survival rate 56%. Grade 3 complications occurred in 10% of the cases and only in patients who had received irradiation during the initial treatment of the primary tumor.

CONCLUSIONS

This brachytherapy technique makes it possible to perform Iridium 192 implants in a difficult situation with a favorable long-term control rate and an acceptable rate of complications.

Pulsed low dose rate brachytherapy in a rat model: dependence of late rectal injury on radiation pulse size

PURPOSE

Clinical protocols utilizing pulsed low dose rate brachytherapy (PDR) to replace traditional continuous low dose rate brachytherapy (CLDR) employ irradiation in individual pulses given at intervals of a few hours. A critical factor in determining whether PDR will produce equivalent or greater late-occurring normal tissue toxicity is the dose per pulse. A rat rectal model was used to determine the role of pulse size in modifying dose effectiveness in producing late-occurring toxicity.

METHODS AND MATERIALS

A rat model in which the rectum is irradiated with 192Ir sources was used in conjunction with an intracavitary applicator. A section of rectum 1.3 cm in length was irradiated with either 0.75 Gy/h CLDR or one of five schemes of PDR. The schemes applied 0.375, 0.75, 1.5, 3.0, or 6.0 Gy pulses at 0.5, 1.0, 2.0, 4.0, or 8.0 h intervals, respectively. Rats were observed for up to 300 days after completion of irradiation for rectal obstruction. Rectal specimens were taken at the time of sacrifice for obstruction or at the end of follow-up and analyzed histologically for injury.

RESULTS

Effectiveness of irradiation was analyzed by calculating the ED50 for incidence of obstruction and severe histological injury. The ED50 for obstruction after treatment with CLDR and pulse sizes of 0.375, 0.75, and 1.5 Gy were 70.5, 68.0, 68.6, and 68.8 Gy, respectively. These values were not significantly different. Compared to CLDR, the ED50 for obstruction after pulse sizes of 3.0 and 6.0 Gy were significantly different at 60.9 and 46.3 Gy, respectively. The relative changes in ED50 for the different radiation schemes in producing ulceration, fibrosis, and vascular sclerosis injury were similar to that observed for obstruction. The endpoints of colitis cystica profunda and atypical epithelial regeneration varied less with increasing pulse size.

CONCLUSIONS

We have demonstrated that for late rat rectal injury, dose responses to PDR pulse sizes up to 1.5 Gy at 2-h intervals are not distinguishable from that seen with CLDR at a dose rate of 0.75 Gy/h.

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.

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.

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.

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.

Salvage treatment for inoperable neck nodes in head and neck cancer using combined iridium-192 brachytherapy and surgical reconstruction

The results of debulking surgery and re-irradiation with radioactive implants (brachytherapy) are reported for 39 patients with inoperable metastatic neck nodes from primary head and neck cancers. For 13 patients conventional salvage by partial debulking surgery and brachytherapy proved effective, with 68 per cent control at 1 year, but six patients suffered severe radiation fibrosis, necrosis and contractures. Some 26 patients were treated by combined tumour debulking, skin resurfacing and brachytherapy implant. Initial tumour control and freedom from serious toxicity was achieved in 24 patients. Local control was achieved in 63 per cent of patients at 1 year, with a serious morbidity rate of 12 per cent.

External beam and intraluminal radiotherapy for locally advanced bile duct cancer: role and tolerability

BACKGROUND AND PURPOSE

Cholangiocarcinoma is rare but carries a poor prognosis. Radiotherapy has been used either as an adjuvant treatment following surgical resection of tumour or for palliation. The purpose of this study was to assess the feasibility and morbidity of accelerated external beam radiotherapy with or without intraluminal radiotherapy in the treatment of locally advanced bile duct cancer.

MATERIALS AND METHODS

Thirty eight patients were treated. Surgical procedures performed prior to radiotherapy were extended hepatectomy (3), hepaticojejunostomy with tumour resection (6), palliative biliary-enteric bypass (6), biopsy (4), Whipple's procedure (1), gastrojejunostomy (1) and cholecystectomy (1). Twenty patients received external beam radiotherapy (ERT). Six patients received one Phase of ERT and 12 received two Phases, separated by a 2-week gap. Dose per Phase was 22.5 Gy in 10 twice daily fractions. After 1989, dose per Phase was increased to 27.5 Gy. One patient received Phase I ERT (30.0 Gy) using conventional fractionation and one patient received an uninterrupted, conventionally fractionate course of treatment (50.0 Gy). Fourteen patients received both ERT and intraluminal radiotherapy (IRT) using iridium-192 (192Ir) wire passed through a percutaneous, transhepatic catheter (median dose, ERT 23.8 Gy + IRT 40.0 Gy). In addition, four patients received IRT alone (median dose 45.0 Gy at 1 cm radius). Patients were followed for at least 42 months.

RESULTS

Median overall survival was 15 months. Overall survival for the whole group at 1,2 and 3 years was 59.6%, 32.5% and 16.2%. Thirty four patients died of disease. Radiotherapy caused acute toxicity in seven patients. According to RTOG/EORTC criteria toxicity was Grade 1 in four cases, Grade 2 in two cases and Grade 3 in one case. Two patients developed gastrointestinal bleeding as a late complication of radiotherapy.

CONCLUSIONS

Accelerated external beam radiotherapy with or without intraluminal radiotherapy is feasible and associated with acceptable toxicity when used in the management of advance cholangiocarcinoma.

Combined surgery and brachytherapy in the treatment of some cancers of the bladder (partial cystectomy and interstitial iridium-192)

Eighty-five bladder cancers were treated at the Urology Clinic of Nancy and the Centre Alexis Vautrin from 1975 to 1992 with short course preoperative radiation therapy (3 x 3.5 Gy), conservative surgery and brachytherapy by iridium-192. The tumours were classified according to the 1979 UICC pTNM classification. There were 27 pT1, 31 pT2 and 22 pT3, two pT4 and three pTx. The pT1-pT2 cases received only one brachytherapy (50 Gy at least) after the short course preoperative irradiation. The pT3 cases received only 30 Gy of brachytherapy and an external irradiation boost (generally 40 Gy to the node areas and 30 Gy to the tumour, but the dose varied during the time course). Surgery was often preceded by an endoscopic resection consisting of a tumoral resection or a partial cystectomy according to the localisation. The plastic vector tubes were put into place at the time of partial cystectomy. Until 1983 the radioactive wires were loaded into the vector tubes on the day following surgery, thereafter it was done one week later. The 85 patients were classified into two groups: 63 patients who were untreated previously and 22 patients who had received one or more endoscopic resections for recurrences. The median follow-up was 84 months. The local controls at 5 years were 78% in the first group versus 56% in the second group (p = 0.005) with an overall survival of 73 and 65%, respectively. The local control did not vary according to the differentiation (grade 1/2 vs. grade 3). The local control for pT1, pT2, pT3 was 85, 64 and 70% with a specific survival of 85, 76 and 72%, and an overall survival of 78, 66 and 66%. Among early complications, delay in healing of the bladder wall with subsequent vesico-cutaneous fistula depends mainly on the loading time of radioactive wires after surgery and is rare if the loading is delayed by one week. The late complications depend mostly on dosimetric factors. We found 24 grade 1, three grade 2, four grade 3 and one grade 4. The following factors are significant: the surface treated (> 14 cm2), a distance between the sources of more than 2 cm and, especially, activity of the wires of more than 2 mCi/cm (this factor was found in the five complications of grade 3 and 4), the other factors were not significant in univariate analyses.

[Osteoradionecrosis of the jaws]

9 patients with osteoradionecrosis of the mandible were treated during 1975-1994. All primary tumor had received high dose external radiation or brachytherapy, using iridium-192 sources. In 6 patients the complication was triggered, shortly before or after irradiation, by surgical interventions such as tooth extraction, or by the presence of an infected focus in the mandible. The complications were treated conservatively, including 2 cases by hyperbaric oxygen. The value of prevention is emphasized.

192Ir induced radiation damage in monkey brain assessed with magnetic resonance imaging and histological examination

The effects of irradiation on a large volume of normal brain tissue as occurs in interstitial brachytherapy were investigated. Double iridium-192 seed assemblies were stereotactically implanted into the right centrum semiovale of eight adult Japanese monkeys (Macaca fuscata). The morphological changes induced in the normal brain tissue were evaluated with magnetic resonance (MR) imaging with and without gadolinium-diethylenetriaminepenta-acetic acid (Gd) enhancement at 2 days and 1, 3, and 6 months after the brachytherapy. After each MR imaging examination, randomly selected experimental animals were sacrificed to analyze the histological changes. The low intensity area seen inside the ring of contrast enhancement on the T1-weighted image with Gd enhancement was well correlated with histologically defined necrosis. The high intensity area seen outside the area showing contrast enhancement on the T2-weighted image was well correlated with an area of histological edema and demyelination. The sizes of the lesion and the high intensity area were maximum during the acute stage (2 days) following interstitial irradiation. This monkey model with MR imaging can be used to investigate the development of brain damage induced by interstitial irradiation. We further recommend careful monitoring to detect the development of brain edema during the acute stage after interstitial brachytherapy, especially when large tumors are treated.

[Long-term follow-up of actinic thoracic wall ulceration after radiation accident caused by an industrial radiation source]

The long-term outcome of a patient injured by an industrial x-irradiation-source is demonstrated and the problems of actinic chest wall damage as well as the development of plastic surgery technique within a 25 year period is discussed by means of this case report.

Iridium-192 interstitial brachytherapy for equine periocular tumours: treatment results and prognostic factors in 115 horses

One hundred and fifteen horses with periocular tumours were treated with iridium-192 interstitial brachytherapy. Tumours included squamous cell carcinomas (n = 52) and sarcoids (n = 63). All horses were scheduled to receive 60 Gy (minimal tumour dose) given at a low dose rate (0.034 +/- 0.010 Gy/h). The mean and median follow-up times to last contact or death were 24 and 16 months, respectively. Chronic radiation reactions included palpebral fibrosis (10.4%), cataract (7.8%), keratitis and corneal ulceration (6.9%). Cosmetic changes included permanent epilation (21.7%) and hair dyspigmentation (78.3%). The one year progression-free survival (PFS) rates for sarcoids and carcinomas were 86.6% and 81.8% and the 5 year PFS rates were 74.0% and 63.5%, respectively. The horse age and sex, histopathological type, anatomical subsite and classification (WHO T1-3) were included in the analysis of prognostic factors. The only significant prognostic factor that independently affected PFS time was the WHO T-classification (P = 0.009, relative risk = 0.85). When compared to horses with T1 lesions, horses with T2 and T3 lesions had 1.8-fold and 3.4-fold increased risks, respectively, for tumour recurrence (relative excess risk). The one year PFS rates for T1, T2 and T3 lesions were 95.2%, 89.5% and 66.2%, respectively. The 5 year PFS rates were 72.2%, 74.0% and 53.1%, respectively. The results of this study indicate that irradiation is an effective treatment option for horses with T1-2 lesions and should be part of a combined treatment modality for horses with T3 lesions.

Salvage irradiation by brachytherapy of velotonsillar squamous cell carcinoma in a previously irradiated field: results in 73 cases

PURPOSE

The salvage brachytherapy performed in patients presenting velotonsillar carcinoma in a previously irradiated field is evaluated in terms of local control, complications and survival.

METHODS AND MATERIALS

Between 1976 and 1990, 73 patients presenting with velotonsillar squamous cell carcinoma in a previously irradiated area were treated at Center Alexis Vautrin with brachytherapy along using an 192Ir implant (afterloading technique) with curative intent. According to the UICC 1987 TNM classification, there were 45 T1 N0, 20 T2 N0, one T3 NO, one T3 N2 and six Tx Nx.

RESULTS

The 5-year actuarial local control for T1 N0 and T2 N0 are 80% and 67% respectively. The regional relapse rate was 10% in both groups. Grade 2 complications occurred in 13% of patients and these were neither related to the volume treated nor the dose rate. There were no Grade 3 or 4 complications. The 5-year specific survival is 64%, with a plateau after the 5th year, but the 5-year overall survival is only 30%. Fourty-two percent of the patients in this series died from another carcinoma. All but two of these were related to continued alcohol and tobacco intoxication.

CONCLUSION

We conclude that brachytherapy alone (60 Gy) is optimal treatment for patients presenting with velontonsillar carcinoma in a previously irradiated field. The greatest challenge is the screening of these patients and the prevention of subsequent head and neck cancers. Recognizing the fact that these patients are at high risk for subsequent malignancies of upper aerodigestive tract, lung and esophagus, close surveillance is necessary for: (a) early diagnosis and prompt treatment; and (b) development of prevention strategies of field cancerization.

Place of Iridium 192 implantation in definitive irradiation of faucial arch squamous cell carcinomas

PURPOSE

We have reviewed the results of 165 T1 and T2 squamous cell carcinomas of the faucial arch treated by definitive irradiation including or not Iridium 192 brachytherapy to ascertain whether a significant relationship existed between Iridium implantation, local control, complications, and survival.

METHODS AND MATERIALS

From March 1971 to November 1990, 58 T1 and 107 T2 (NO: 107/165; N1: 30/165; N2: 9/165; N3: 19/165) biopsy proven squamous cell carcinomas of the tonsillar region (104/165) and the soft palate and uvula (61/165) were treated in Henri Mondor Hospital by definitive irradiation with curative intent. From 1971 to 1981 (period 1), only guide gutter technique was available, so that implants were reserved for small tumors: patients were either managed by definitive telecobaltherapy to tumor site and neck node areas (Group 1; n = 48; mean dose: 70 Gy; confidence interval: +/- 5.5; 5 fractions of 1.8 Gy per week) or by exclusive Iridium implant (Group 2; n = 11; all T1NO; 64 Gy +/- 4.8) or by a combination of external beam radiation therapy to tumor site and neck nodes areas and Iridium implant (Group 3; n = 40). In 1981 (Period 2), a new plastic tube technique, which enables implantation of larger areas, was introduced in the department and all patients (Group 4; n = 66) were then managed by external radiation therapy (Group 3 + 4: 47 Gy +/- 4.3) followed by an Iridium implant (31 Gy +/- 10.5). Clinically positive neck nodes either received additional external dose with electrons or were excised.

RESULTS

Overall 5-year survival (Kaplan Meier) was 21%, 50.5%, and 60% in groups 1, 2, and 3 + 4, respectively (p < 0.001, log rank). Five-year local control was 58%, 100%, and 91%, respectively (p < 0.001). Five-year necrosis rate was 4.5%, 20.5% and 18%, respectively (N.S.). Comparison of results between the two periods of the study (Group 1 + 2 + 3 vs. group 4) show that these two groups are statistically comparable according to site and size of tumor and N status and that both local control (77% vs. 94% at 5 years; p < 0.01) and disease-free survival (56% vs. 71%; p = 0.03) were improved after 1980, while there was a trend to an increase in overall survival (42% vs. 53% at 5 years; p = 0.08); nodal control (86% vs. 95% at 5 years), and necrosis rate (11% vs. 20% at 5 years) were not modified. Multivariate analysis showed that both local control (p < 0.0001) and overall survival (p < 0.0001) were improved when tumor was implanted.

CONCLUSION

We recommend then to treat T1 and T2 squamous cell carcinomas of the faucial arch by external radiation therapy to tumor site and neck areas (45 Gy/25 fractions/5 weeks) followed by a 30 Gy Iridium implant and, for patients with clinically positive nodes, either a further 25-30 Gy electron beam irradiation to the nodes or neck node dissection.

[Radiation stenosis and fistula formation developed after iridium-192 high-dose-rate intracavitary radiation boost therapy for carcinoma of the esophagus]

Intracavitary irradiation using a high-dose-rate Ir-192 remote after-loading system was applied to 14 advanced or inoperable patients with esophageal carcinoma as a boost therapy. The total dose of external irradiation was 45-70 Gy/15-35 fractions and that of intracavitary irradiation was 11.6-34.0 Gy/2-4 fractions at a point 5 mm deep from the inner surface of the esophageal mucosa. The time-dose-fractionation factor (TDF) of the whole treatment was 116-186 (mean, 146). Six patients (43%) had complete response (CR), three (21%) had partial response and five (36%) had no response. Esophageal carcinoma that showed exophytic growth, was less than 5 cm ling, and showed favorable response to external irradiation was likely to be a good candidate for intracavitary radiation boost therapy. Fistula formation was produced in five patients (36%), four of whom were irradiated at more than 140 TDF. All six CR patients were free from esophageal tumors, but severe esophageal stenosis due to radiation injury developed in five (83%) of them. They were irradiated at more than 135 TDF. One- and two-year survival rates were 28.6% and 14.3%, respectively. The poor prognosis was ascribed to the frequent occurrence of fatal radiation stenosis and fistula formation. An appropriate therapeutic dose for esophageal carcinoma that does not cause severe radiation stenosis was estimated to be under 120 TDF.

Carcinoma of the penis: a retrospective review of treatment with iridium mould and external beam irradiation

This paper is a retrospective review of the treatment of carcinoma of the penis with radiotherapy alone over a 30-year period from 1960-1990 at The Royal London Hospital. During that time, 44 patients aged 31-85 years (mean 63) underwent treatment in our department, all of whom had histologically proven squamous carcinoma. Patients initially treated by surgery and those treated with combined surgery and radiotherapy were excluded from analysis. Twenty-four patients were treated by an iridium mould, and 20 by external beam irradiation. There were 67% complete responses; 79% for the patients treated by an iridium mould, 53% for those treated by external beam irradiation, although this difference between the two treatment groups was due to a more favourable stage distribution in the iridium group. Actuarial 2-, 5- and 10-year overall survivals were 87.9%, 85.1% and 72.3% respectively, with no significant difference between the iridium and external beam groups. For Stage I patients, the response rates and actuarial penile disease free survivals were comparable for the iridium and external beam groups. Urethral stricture was recorded in 10% of those treated by external beam irradiation and 13% of those treated by iridium mould. These results confirm that conservative treatment of carcinoma of the penis with radical radiotherapy allows preservation of a functioning penis with acceptable morbidity and a high proportion of long term survivors when surgery is used for salvage of locoregional relapse.(ABSTRACT TRUNCATED AT 250 WORDS)

[Radiobiological research to optimize high-dose-rate afterloading therapy with Ir-192 in extragenital tumors]

Since the introduction of the high-dose rate afterloading therapy a higher biological effectivity of this method has been well known in comparison with the low-dose contact therapy. This will practically taken into account by reducing the dose and more fractionating of the total dose. With our test we want: firstly to prove the influence of the therapy break on the duration of the radiation reaction. Secondly we want to prove the influence of the dose rate on the efficiency of the radiation reaction. We have tried to answer the question by the animal model guinea pig skin. We examined early reactions as well late reactions.