Lip cancer treatment with high dose rate brachytherapy.

We present 39 patients with lip carcinoma treated with HDR, (needles) with 5-5.5 Gy per 8-10 fractions b.i.d. (total dose 40.5-45 Gy). Three-year cause-specific survival and local control are 91 and 88% (95% T1-2, 74% T4, p<0.05). Acute and chronic reactions are like LDR cases. We think that HDR results are equivalent to LDR.     

Intracavitary radiation in the treatment of advanced esophageal carcinoma: A comparison of high dose rate vs. low dose rate brachytherapy

Twenty-two patients were irradiated using two different dose schedules of intracavitary irradiation for palliation of locally advanced or metastatic carcinoma of the esophagus. Irradiation was given solely with either manually afterloaded low/Intermediate dose Cesium-137 (LDR) or high dose rate Iridium-192 (HDR) delivered via remote afterloader. This study was designed to test the effectiveness of HDR intracavitary brachytherapy in the relief of dysphagia and the maintenance of esophageal patency and to compare with our previous experiences with LDR intracavitary brachytherapy. Accelerated treatments were especially suited for patients with poor physical condition or short life expectancy unlikely to complete a full course of external beam irradiation without treatment interruption. Two thousand cGY in three fractions of LDR was compared with 1,250 cGY in one fraction HDR with essentially equal results. © 1993 Wiley-Liss, Inc.     

Cervix cancer brachytherapy: High dose rate

Cervical cancer, although less common in industrialized countries, is the fourth most common cancer affecting women worldwide and the fourth leading cause of cancer death. In developing countries, these cancers are often discovered at a later stage in the form of locally advanced tumour with a poor prognosis. Depending on the stage of the disease, treatment is mainly based on a chemoradiotherapy followed by uterovaginal brachytherapy ending by a potential remaining tumour surgery or in principle for some teams. The role of irradiation is crucial to ensure a better local control. It has been shown that the more the delivered dose is important, the better the local results are. In order to preserve the maximum of organs at risk and to allow this dose escalation, brachytherapy (intracavitary and/or interstitial) has been progressively introduced. Its evolution and its progressive improvement have led to the development of high dose rate brachytherapy, the advantages of which are especially based on the possibility of outpatient treatment while maintaining the effectiveness of other brachytherapy forms (i.e., low dose rate or pulsed dose rate). Numerous innovations have also been completed in the field of imaging, leading to a progress in treatment planning systems by switching from two-dimensional form to a three-dimensional one. Image-guided brachytherapy allows more precise target volume delineation as well as an optimized dosimetry permitting a better coverage of target volumes.     

Percutaneous and endobronchial high dose rate brachytherapy for lung cancer

Endobronchial and percutaneous high dose rate (HDR) brachytherapy was performed with a microSelectron HDR using iridium-192 as a radiation source. As spontaneous pain was uncontrollable by external beam radiation (EBR), chemotherapy, hyperthermia or a combination of these treatment methods, three patients with lung cancer infiltration into the chest wall underwent percutaneous HDR brachytherapy for palliation of severe pain. Selectron needles were inserted under CT guidance and the irradiation dose was set to 10 or 12 Gy at the point 1 cm from the center of the radiation source. A total of 2-4 selectron needles was introduced by means of a template. Irradiation was performed once a week for 1-2 weeks depending on the degree of alleviation of spontaneous pain. In all 3 cases, alleviation of spontaneous pain occured within 7 days after the completion of HDR brachytherapy, and the mean pain score decreased from a value of 2 to 1 within 2 weeks. After discharge from the hospital, the pain score remained between 1-4 in all 3 patients. One problem in percutaneous brachytherapy is the possible hindrance of multiple selectron needle insertion through the template by the ribs depending on the location of the lesion. Six patients aged 51-75 years were subjected to endobronchial HDR brachytherapy. Two of these patients had postoperative recurrence of lung cancer, and 3 patients received concomitant chemotherapy. Brachytherapy was performed 3.4 months (average) after the administartion of 40-70 Gy of EBR. Endobronchial irradiation was performed at a dose of 7 Gy, measured at 1 cm from the center of the radiation source, once a week over a 3 week period for a total of 21 Gy. With the exception of 2 patients who died due to systemic exacerbation, local control of the illness has been good. In endobronchial HDR brachytherapy, it is important to develop a system for altering radiation dose in response to changes in the caliber of the tracheobronchial tree and the degree of the tumor invasion under the bronchial mucosa.     

Urethral stricture following high dose rate brachytherapy for prostate cancer

Purpose

To evaluate the incidence, timing, nature and outcome of urethral strictures following high dose rate brachytherapy (HDRB) for prostate carcinoma.

Methods and materials

Data from 474 patients with clinically localised prostate cancer treated with HDRB were analysed. Ninety percent received HDRB as a boost to external beam radiotherapy (HDRBB) and the remainder as monotherapy (HDRBM). Urethral strictures were graded according to the Common Terminology Criteria for Adverse Events v3.0.

Results

At a median follow-up of 41 months, 38 patients (8%) were diagnosed with a urethral stricture (6-year actuarial risk 12%). Stricture location was bulbo-membranous (BM) urethra in 92.1%. The overall actuarial rate of grade 2 or more BM urethral stricture was estimated at 10.8% (95% CI 7.0-14.9%), with a median time to diagnosis of 22 months (range 10-68 months). All strictures were initially managed with either dilatation (n = 15) or optical urethrotomy (n = 20). Second line therapy was required in 17 cases (49%), third line in three cases (9%) and 1 patient open urethroplasty (grade 3 toxicity). Predictive factors on multivariate analysis were prior trans-urethral resection of prostate (hazard ratio (HR) 2.81, 95% CI 1.15-6.85, p = 0.023); hypertension (HR 2.83, 95% CI 1.37-5.85, p = 0.005); and dose per fraction used in HDR (HR for 1 Gy increase per fraction 1.33, 95% CI 1.08-1.64, p = 0.008).

Conclusions

BM urethral strictures are the most common late grade 2 or more urinary toxicity following HDR brachytherapy for prostate cancer. Most are manageable with minimally invasive procedures. Both clinical and dosimetric factors appear to influence the risk of stricture formation.     

Role of high dose rate brachytherapy in the treatment of prostate cancer

High dose rate (HDR) brachytherapy in intermediate and high-risk prostate cancer patients has started in the late eighties in Europe and the United States, as a boost combined with external beam radiation therapy, as an attractive method for dose escalation. The results of the first dose-escalation study performed at William Beaumont Hospital has established the safety and efficacy of this combined treatment approach. Likewise, this landmark study enabled a paradigm shift in the radiobiology of prostate cancer, demonstrating that the alpha/beta of prostate cancer was much lower than previously believed to be and therefore the sensitivity of this tumor model to higher-than-conventional doses per fraction led to a dramatic increase of hypofractionated treatment regimens, the object of significant clinical research efforts, currently under way. The excellent toxicity profile and clinical outcome of HDR boost combined treatment prompted investigators to expand HDR brachytherapy indications to low/intermediate prostate cancer patients as the sole treatment modality. The results, toxicity and a brief review of the literature for both HDR boost and HDR monotherapy will be presented.     

Optimization in high dose rate brachytherapy for utero-vaginal applications.

BACKGROUND AND PURPOSE: High dose rate (HDR) remote afterloading intracavitary brachytherapy is an effective treatment modality which has some advantages over low dose rate (LDR) techniques for gynaecological cancer. Optimization is one of the possibilities of modern brachytherapy techniques, especially the stepping source technology. The use of the term 'optimization' implies achieving the desired optimum dose distribution by changing some parameters of the treatment. The aim of this study was to theoretically evaluate the optimization possibilities by modifying dwell times and dwell positions of the uterine and vaginal sources. MATERIALS AND METHODS: Working on a virtual utero-vaginal model, the dose distribution variations in the rectum, bladder, mean point B reference points and volume parameters were investigated whilst giving a standard dose to point A in the Manchester system. In this model, the intrauterine tandem consisted of 27 dwell positions for 2.5 mm steps and 14 dwell positions for 5 mm steps. Vaginal colpostats consisted of five dwell positions each for 2.5 mm steps. Using a Nucletron Plato treatment planning system and a Microselectron Ir-192 HDR stepping source unit, the dwell times of the intrauterine (T(u)) and vaginal sources (T(v)) were modified at the ratios of (T(u)/T(v)) 1:1; 1:2; 1:3; 1:4; 1:0.50; 1:0.33; and 1:0.25 for the two different dwell positions, 2.5 and 5 mm steps, of the intrauterine tandem. RESULTS: All evaluated parameters decreased with increasing dwell time ratios of uterine tandem to vaginal colpostats, with the greatest fall in the percentage of rectum reference dose (D(R) %), 23 and 28% for 2.5 and 5 mm dwell positions respectively; in addition, the reference isodose volume decreased by 14 and 17% for 2.5 and 5 mm dwell positions, respectively. All evaluated parameters increased with decreasing dwell time ratios of uterine tandem to vaginal colpostats for both dwell positions. The DR% of 1:1-1:4 (T(u)/T(v)) weightings showed an increase from 40.6 to 58.3 (44%) for 2.5 mm and from 49.2 to 67.5 (37%) for 5 mm dwell positions. The volume was increased by 27 and 37% for 2.5 and 5 mm dwell positions respectively. CONCLUSION: Modern brachytherapy techniques enable the individualization of treatments by optimization procedures in gynaecological brachytherapy applications. By altering the dwell time and position, some important changes in reference points, volume and treatment time can be achieved, whilst maintaining a standard dose to point A.     

Radiation therapy of esophageal cancer

Radiation therapy has been used extensively in the management of patients with cancer of the esophagus. It has demonstrated an ability to cure a small minority of patients. Cure is likely to be limited to patients who have lesions less than 5 cm in length and have minimal, if any, involvement of lymph nodes. Esophagectomy is likely to cure a similar, small percentage of patients with the same presentation of minimal disease but has a substantial acute postoperative mortality rate and greater morbidity than irradiation. Combining surgery and either preoperative or postoperative irradiation may cure a small percentage of patients beyond the number cured with either modality alone. Radiation has demonstrated benefit as an adjuvant to surgery following the resection of minimal disease. However, radiation alone has never been compared directly with surgery for the highly select, minimal lesions managed by surgery. Radiation provides good palliation of dysphagia in the majority of patients, and roughly one third may have adequate swallowing for the duration of their illness when "radical" doses have been employed. Surgical bypass procedures have greater acute morbidity but appear to provide more reliable, prolonged palliation of dysphagia. They constitute the best approach for patients with persistent or recurrent dysphagia following esophageal irradiation. Several approaches to improving the efficacy of irradiation are currently under investigation. Fewer large fractions appear to be equivalent to conventionally fractionated radiotherapy in terms of local control and survival but produce more prompt palliation and shorten courses of palliative therapy. Multiple-daily-fractionation schedules and hyperfractionation have theoretical appeal and clear basis for investigation from the early suggestions of improved response rates in advanced squamous-cell cancer of the head and neck. Hypoxic-cell radiosensitizers, neutron-beam, and helium-ion therapy results have not been overly encouraging in esophageal cancer, thus far. However, the new generation of particle beams and the new radiation-sensitizer drugs require further evaluation. Better means of dealing with the high incidence of disseminated disease are clearly needed. It is clear that combined-modality approaches using both local and systemic therapy will ultimately be desirable in esophageal-cancer treatment.(ABSTRACT TRUNCATED AT 400 WORDS)     

Imaging technologies for high dose rate brachytherapy for cervical cancer: a systematic review

The aim of this overview was to assess the utility of various imaging technologies (fluoroscopy, ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography) for the treatment planning of high dose rate brachytherapy for cervical cancer. Reviews and primary studies comparing different imaging technologies used during high dose rate brachytherapy for cervical cancer and published from 1988 to 2008 were sought by searching MEDLINE and EMBASE databases, the Cochrane Library, personal files and reference lists of identified studies, and by contacting experts. Study selection, study quality assessment and data extraction were carried out in duplicate. Twelve studies met the inclusion criteria. No systematic reviews or randomised controlled studies (RCTs) were located. The validity assessment revealed that the quality of the existing studies is very variable. This is the first systematic review in the area of imaging technologies for cervix brachytherapy. No RCTs have been located and it is possible that an RCT is not the optimal methodology to assess imaging technologies. However, in this area there is a need for more prospective studies and for studies that consider the expertise of the operators in their design. The studies found supported the use of three-dimensional imaging as opposed to the traditional two-dimensional imaging. However, apart from the effectiveness of visualising tumours and surrounding tissues, the utility of imaging technologies in clinical practice is determined by other contextual factors, such as their availability, accessibility and ease of use.     

Post-operative high dose rate brachytherapy in patients with low to intermediate risk endometrial cancer.

BACKGROUND AND PURPOSE: This paper investigates the outcome using different dose/fractionation schedules in high dose rate (HDR) post-operative vaginal vault radiotherapy in patients with low to intermediate risk endometrial cancer. MATERIALS AND METHODS: The world literature was reviewed and thirteen series were analyzed representing 1800 cases. RESULTS: A total of 12 vaginal vault recurrences were identified representing an overall vaginal control rate of 99.3%. A wide range of dose fractionation schedules and techniques have been reported. In order to analyze a dose response relationship for tumor control and complications, the biologically effective doses to the tumor and late responding tissues were calculated using the linear quadratic model. A threshold was identified for complications, but not vaginal control. While dose fractionation schedules that delivered a biologically effective dose to the late responding tissues in excess of 100 Gy(3) (LQED=60 Gy) predicted for late complications, dose fractionation schedules that delivered a modest dose to the vaginal surface (50 Gy(10) or LQED=30 Gy) appeared tumoricidal with vaginal control rates of at least 98%. CONCLUSIONS: By using convenient, modest dose fractionation schedules, HDR vaginal vault - brachytherapy yields very high local control and extremely low morbidity rates.     

Dosimetric comparisons between high dose rate interstitial and MammoSite balloon brachytherapy for breast cancer.

BACKGROUND AND PURPOSE: To make a quantitative dosimetric comparison between treatment plans of multicatheter-based interstitial brachytherapy (IB) and MammoSite brachytherapy (MSB) for breast cancer. PATIENTS AND METHODS: Seventeen patients treated with IB and twenty-four with MSB were selected for the study. The irradiations for IB patients were planned using conventional two-film reconstruction technique. Following the implantation each patient was CT scanned, then the planning target volume (PTV) was retrospectively defined on the CT data set, and the original plan was reconstructed (CONV plans). Furthermore, conformal plans were also created by dose optimization on target (CONF plans). The planning for MammoSite applicator was based on CT imaging. The dose distributions were evaluated with dose-volume histograms. The following parameters were calculated and compared: volume of the PTV and its percentage receiving 90, 100, 150 and 200% of the prescribed dose (V90, V100, V150 and V200, respectively), percentage dose covering 90% of the PTV (D90), minimum dose in the PTV (D(min)), maximum dose in the PTV (D(max)) for MSB only, dose homogeneity index (DHI), and conformal index (COIN). To assess the dose to organs at risk maximum point dose to skin, lung and heart was used. RESULTS: The median number of implanted catheters for IB was 11 (range: 6-13), the average balloon volume for MSB was 59.1cm(3) (range: 43.4-75.3 cm(3)). The average volume of PTV was 63.4 and 109.6 cm(3) for IB and MSB patients, respectively. The average V90, V100, V150, V200 were 76, 70, 26 and 9% for IB(CONV); 92, 87, 55 and 32% for IB(CONF) and 96, 88, 27 and 3% for MSB, respectively. The average D90 was 72, 94 and 99%, the D(min) was 47, 58 and 67%, respectively. The mean D(max) was 258% for MSB. The average DHI was 0.63, 0.37 and 0.70 for IB(CONV), IB(CONF) and MSB, respectively. D(max) to skin, lung and heart were 45, 54 and 31% for IB(CONV), 50, 55 and 29% for IB(CONF,) 97, 66 and 27% for MSB, respectively. CONCLUSIONS: Target volume coverage was better for MSB than conventional IB, and it was comparable to conformal IB. The suboptimal coverage for IB patients is due to radiography based planning, which is unable to provide 3D information of the target. Dose homogeneity was somewhat better for MSB than IB(CONV), but the dose to skin and lung was higher for MSB. The MSB provides dosimetrically acceptable dose plans. The quality of interstitial implants can be improved with image-guided catheter insertions regarding both homogeneity and conformality.     

A teaching booklet for patients receiving high dose rate brachytherapy.

A teaching booklet developed for patients with lung cancer who were about to receive high dose rate (HDR) brachytherapy is described and presented. The booklet was developed by nurses assigned to a radiation oncology center and details the procedure using text and photographs.     

Intrauterine high dose rate afterloading brachytherapy: Experience of fractionated therapy using a cervical sleeve technique

Using a standard three-channel Manchester-type tube and ovoid high dose rate applicator system, 46 consecutive patients have been treated for carcinoma of the cervix or endometrium. To facilitate fractionated treatments using high dose rate afterloading, a technique has been developed using an indwelling cervical sleeve inserted under an initial general anaesthetic. All patients received at least two insertions; in five patients we have delivered a total of six consecutive fractions on an outpatient basis without anaesthesia once the sleeve was in situ. Acute morbidity related to the procedure was some degree of uterine pain, which was relieved with nitrous oxide inhalation, and mild, but self-limiting, vaginal discharge. Complete late morbidity data are not yet available, but, in 30% of 25 evaluable patients, minor problems have been observed, particularly vaginal oedema and stenosis. Only one major late event has required surgery.Fractionated afterloading intrauterine brachytherapy can be delivered on an outpatient basis without anaesthesia using this cervical sleeve technique.     

Treatment of non-small cell lung cancer with external beam radiotherapy and high dose rate brachytherapy.

Between August 1985 and September 1989, 62 patients with medically inoperable or surgically unresectable, non-small cell lung cancer were treated with both external beam radiotherapy and high dose rate bronchial brachytherapy. Treatment consisted of external beam radiotherapy (5000-6000 cGy in 5-6 1/2 weeks) and weekly high dose rate bronchial brachytherapy (three to five fractions, 500 cGy at 1 cm from the source) delivered either concurrently or sequentially. Median survival for all patients was 13 months (m). Stage I and Stage IIIA-B patients had median survivals of 20 m and 10 m, respectively. Patients without nodal disease (No) had a significantly longer median survival compared to patients with regional node metastases (N1-3), 17 m versus 9 m. A total of 54 patients were evaluable for local tumor control analysis. Local tumor control was achieved in six of eight patients who had a normal pre-treatment radiograph. Patients with measurable tumor on the pre-treatment radiograph and negative regional nodes had local tumor control in eight of twenty-two (36%) cases. In patients with regional lymphadenopathy, loco-regional tumor control was achieved in four of eight cases. Additionally, there were sixteen patients with non-measurable tumor due to associated effusion, atelectasis and/or infiltrate. Four of these (25%) were considered to have local tumor control. Of 60 evaluable patients, there were nine occurrences of fatal hemorrhage, one of whom was disease-free (NED) at autopsy. The remaining eight patients had either clinical or pathological evidence of recurrent or persistent tumor. Patients who had follow up bronchoscopies were found to have varying degrees of concentric narrowing in the treated areas. One such patient had total lung collapse with no evidence of tumor. While this form of treatment may yield high local control rates in earlier stages, this study suggests the potential risk of fatal complication. Additional studies are warranted to further investigate the use of this modality in the treatment of lung cancer.     

High dose rate brachytherapy in the treatment of prostate cancer.

Because the HDR brachytherapy treatments are delivered within minutes and on an outpatient basis, HDR brachytherapy is very well tolerated by patients and offers complete radiation safety. Published studies2, 11, 12, 13, 16, 17, 18, 22, 24, 25 have shown high local clinical and biochemical control rates. Chronic complications have been acceptably low. Very low rates of urinary incontinence and high sexual potency rates have been reported. Gastrointestinal morbidity has been minimal. The development of Ir-192 HDR afterloading brachytherapy and refinements in the dosimetry have ushered in a new era in prostate brachytherapy. The control of the radiation dose and the ability to shape the radiation treatment envelope using a stepping source have allowed a giant step forward in radiation oncology technology. It is now possible to deliver tumoricidal doses of radiation conformally to the prostate while minimizing the dose to the bladder, urethra, and rectum. At present, HDR afterloaded brachytherapy is the optimal whole-organ and tumor-specific conformal radiation therapy for prostate cancer.