High dose rate brachytherapy boost treatment in radical radiotherapy for prostate cancer.

The natural history of prostate cancer is for early invasion of the prostatic capsule and seminal vesicles. This will be present in the majority of patients presenting with a prostate specific antigen (PSA) >10 or Gleason score >7. In these patients a combination of external beam treatment to provide a regional dose of radiation followed by a high dose rate afterloading brachytherapy boost to enable conformal dose escalation within the prostate gland presents an attractive option in local treatment. Accurate placement of catheters is now possible using transrectal ultrasound to provide high quality implants. A number of centres have now developed this technique as a routine clinical tool. There remains variation in the optimal dose fractionation with a range of BED(10) values from 100 to 77 and BED(3) values from 246.6 to 122.5. This does not, however, take into account geometric variations in dose distribution exploiting the physical advantage of BT in achieving a rapid dose fall off close to critical structures such as the rectum. Early results show PSA response levels of around 90% with grade III toxicity in 5-9% of patients. Critical evaluation of this technique in prospective, randomized trials is required.     

High dose rate brachytherapy boost for prostate cancer: A systematic review

Studies of dose-escalated external beam radiation therapy (EBRT) and low dose rate brachytherapy (LDR-BT) have shown excellent rates of tumor control and cancer specific survival. Moreover, LDR-BT combined with EBRT (i.e. “LDR-BT boost”) is hypothesized to improve local control. While phase II trials with LDR-BT boost have produced mature data of outcomes and toxicities, high dose rate (HDR)-BT has been growing in popularity as an alternative boost therapy. Boost from HDR-BT has theoretical advantages over LDR-BT, including improved cancer cell death and better dose distribution from customization of catheter dwell times, locations, and inverse dose optimization. Freedom from biochemical failure rates at five years for low-, intermediate-, high-risk, and locally advanced patients have generally been 85–100%, 80–98%, 59–96%, and 34–85%, respectively. Late Radiation Therapy Oncology Group grade 3–4 toxicities have also been encouraging with <6% of patients experiencing any toxicity. Limitations of current HDR-BT boost studies include reports of only single-institution experiences, and unrefined reports of toxicity or patient quality of life. Comparative effectiveness research will help guide clinicians in selecting the most appropriate treatment option for individual patients based on risk-stratification, expected outcomes, toxicities, quality of life, and cost.     

Early-stage breast cancer conservative treatment: high-dose-rate brachytherapy boost in a single fraction of 700 cGy to the tumour bed

Background and purpose  

Conservative treatment represents the current therapy for early-stage breast cancer. When risk factors for local relapse exist, a tumour bed boost is required. Retrospectively, we evaluated the prognostic factors influencing local recurrence (LR), overall survival (OS) and disease-free survival (DFS).     

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.     

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.     

Techniques of tumour bed boost irradiation in breast conserving therapy: current evidence and suggested guidelines

Breast conservation surgery followed by external beam radiotherapy to breast has become the standard of care in management of early carcinoma breast. A boost to the tumour bed after whole breast radiotherapy is employed in view of the pattern of tumour bed recurrences in the index quadrant and was particularly considered in patients with some adverse histopathological characteristics such as positive margins, extensive intraductal carcinoma (EIC), lymphovascular invasion (LVI), etc. There is however, now, a conclusive evidence of improvement in local control rates after a boost radiotherapy dose in patients even without such factors and for all age groups. The maximum absolute reduction of local recurrences by the addition of boost is especially seen in young premenopausal patients. At the same time, the addition of boost is associated with increased risk of worsening of cosmesis and no clear cut survival advantage. Radiological modalities such as fluoroscopy, ultrasound and CT scan have aided in accurate delineation of tumour bed with increasing efficacy. A widespread application of these techniques might ultimately translate into improved local control with minimal cosmetic deficit. The present article discusses the role of radiotherapy boost and the means to delineate and deliver the same, identify the high risk group, optimal technique and the doses and fractionations to be used. It also discusses the extent of adverse cosmetic outcome after boost delivery, means to minimise it and relevance of tumour bed in present day scenario of advanced radiotherapy delivery techniques like (IMRT).     

早期乳腺癌保乳术后瘤床同步加量短疗程放疗临床观察

目的 探讨早期乳腺癌保乳术后瘤床同步加量短疗程放疗疗效、不良反应以及美容效果。方法 2008—2010年本院收治早期乳腺癌保乳术后患者 306例,其中 160例行常规分割放疗(常规组),两野切线全乳照射,后续瘤床电子线推量,总疗程 46~48 d;146例行短疗程放疗(短程组),两野切线全乳照射,同步瘤床电子线推量,总疗程 30~32 d。Kaplan-Meier法计算生存率和局部复发率并Logrank检验差异,χ²检验两组资料可比性、不良反应及美容效果。结果 中位随访时间26个月,随访率为100%。两组1、2、3年生存率均为100%,均无局部复发(χ²=0.00,P=1.000)。常规组与短程组1、2级急性皮肤反应发生率分别为46.9%与45.1%(χ²=0.73,P=0.695)、16.3%与13.7%(χ²=0.73,P=0.695),1级皮肤及皮下组织晚期反应发生率分别为16.9%与17.1%(χ²=0.00,P=0.954);1级中性粒细胞减少发生率分别为11.9%与13.7%(χ²=0.23,P=0.633);美容优良率分别为66.2%与65.5%(χ²=0.01,P=0.927)。结论 保乳术后全乳放疗同步瘤床加量的短疗程方案与常规放疗的疗效相似,美容效果相当且未加重皮肤反应,但还需进一步研究。     

Attitudes and treatment outcome of breast conservation therapy for stage I & II breast cancer using peroperative iridium‐192 implant boost to the tumour bed

Breast conservation therapy for early breast cancer is an established but grossly under‐utilized treatment option in India for various reasons. Breast conservation therapy was offered to 200 suitable breast cancer patients between June 1993 and June 1998. Fifty‐one patients (25%) opted for breast conservation and the remaining preferred mastectomy. In patients agreeing to conservation therapy, surgery was performed first along with peroperative implantation of iridium‐192 to deliver a boost. Whole breast irradiation of 45 Gy was delivered 3–4 weeks after the boost. Cosmesis was assessed at the end of 6 months from completion of therapy. The main reason for refusal of breast conservation therapy was fear of recurrence in the remaining breast (60%). There were no locoregional failures in our study at a median follow up of 42 months; one patient experienced a systemic relapse. Cosmesis was good to excellent in 80% of patients. Breast conservation therapy using peroperative iridium‐192 implant provides excellent locoregional disease control and cosmesis. The results of our study indicate that patient preference for mastectomy is an important reason for the under‐utilization of breast conservation therapy in India.     

High dose rate brachytherapy for superficial cancer of the esophagus

PURPOSE: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. METHODS AND MATERIALS: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. RESULTS: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p = 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. CONCLUSION: High dose rate brachytherapy permits the treating of patients with superficial esophageal cancer with good tolerance. Early tumors, located in the mucosa, might be treated by HDR brachytherapy alone or by a combined modality treatment in which HDR brachytherapy can take place like a boost. This approach may cure localized recurrences.     

High dose rate brachytherapy: its clinical applications and treatment guidelines

Brachytherapy has the advantage of delivering a high dose to the tumor while sparing the surrounding normal tissues. With proper case selection and delivery technique, high-dose-rate (HDR) brachytherapy has great promise, because it eliminates radiation exposure, allows short treatment times, and can be performed on an outpatient basis. Additionally, use of a single-stepping source, allows optimization of dose distribution by varying the dwell time at each dwell position. However, when HDR brachytherapy is used, the treatments must be executed carefully, because the short treatment times do not allow any time for correction of errors, and mistakes can result in harm to patients. Hence, it is very important that all personnel involved in HDR brachytherapy be well trained and be constantly alert. It is expected that the use of HDR brachytherapy will greatly expand over the next decade and that refinements will occur primarily in the integration of imaging (computed tomography, magnetic resonance imaging, intraoperative ultrasonography) and optimization of dose distribution. It is anticipated that better tumor localization and normal tissue definition will help to optimize dose distribution to the tumor and reduce normal tissue exposure. The development of well-controlled randomized trials addressing issues of efficacy, toxicity, quality of life, and costs-versus-benefits will ultimately define the role of HDR brachytherapy in the therapeutic armamentarium.     

Brachytherapy boost to the tumour bed in high risk patients after limited surgery for breast cancer

The results of treatment for 174 patients at high risk of local recurrence, referred for radiotherapy after conservative surgery for early breast cancer, are evaluated. Microscopic margin involvement, extensive carcinoma in situ, and vascular/lymphatic invasion were the main risk factors for local recurrence. Whole-breast irradiation (40 Gy in 15 fractions over 3 weeks) followed with a brachytherapy boost (Ir192 wire implant or PDR Ir192) of 25 Gy was applied. Median follow-up was 80 months. The actuarial 6-year overall survival rate was 91% and the within breast recurrence-free survival was 88%. The most common risk factor among those recurring within the breast was involved surgical margins (13 out of 17). Cosmesis was reported to be good or excellent in 79% of cases. In patients at high risk for local recurrence, tumour-bed boost with brachytherapy can provide satisfactory local control after limited surgery and external radiotherapy.     

Indications and technical aspects of brachytherapy in breast conserving treatment of breast cancer.

Improved local control rates have been demonstrated in retrospective studies as well as in randomised trials on brachytherapy with increasing doses to the tumour bed. The higher local control obtained by interstitial breast implants, as compared to external photon or electron beam boosts, have been mainly attributed to the higher doses actually delivered to the tumour bed by these implants for the same nominal dose as compared to external beam radiotherapy (RT). On the other hand, poor cosmesis has also been correlated with radiation dose to the breast skin (radiation teleangiectases), and breast tissue (retraction due to fibrosis), the latter depending not only on RT dose but also on the treated boost volume. For this reason, a possible benefit of interstitial implants will only be realized when the gain in local control goes together with minimal cosmetic damage. Therefore, the ballistic advantages of interstitial implants have to be maximally exploited: i.e. the treated volume should be maximally adapted to the target volume, and additional irradiation of the breast skin by the boost technique should be avoided. This paper deals in detail with the technical aspects of breast brachytherapy that seem to be relevant for high quality outcome.     

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.     

High dose rate brachytherapy as monotherapy for localised prostate cancer

Background and purpose

To evaluate the oncological outcome of a three-implant high dose rate (HDR) brachytherapy (BRT) protocol as monotherapy for clinically localised prostate cancer.

Early breast cancer with positive margins: excellent local control with an upfront brachytherapy boost

Standard breast conservation therapy consists of lumpectomy and whole breast radiation with boost. The effectiveness of radiation in cases of positive margins is controversial. Two potential treatment-related factors are time to initiation of radiation and localization of the boost. Here, we examine long-term outcomes of positive margin cases treated with an upfront interstitial brachytherapy boost. This particular treatment arrangement may reduce those treatment-related effects on local control. Historically, a low dose interstitial implant was a common boost technique. One approach administered the boost before external beam. A review of 521 cases treated at our institution was conducted. Patients were selected for this study if they received an upfront brachytherapy boost and had close or positive margins. Forty-four breast cancers were identified. Median follow-up of survivors was 11.3 years (8.1-21.7). Implant was performed at lumpectomy (12) or axillary dissection (32). Margin statuses were: focal carcinoma at ink (37), multifocal carcinoma at ink (1), carcinoma <1 mm from ink (2), and DCIS at ink (4). Median tumor size was 1.2 cm (0.5-3.5 cm). Ten patients had nodal involvement. Total median dose was 60 Gy (58.6-65.3 Gy). Median boost dose was 15 Gy (12-20.3 Gy). Lumpectomy to boost interval was median of 3 weeks (0-10.8). No ipsilateral breast recurrences or second primaries were identified. Four developed contralateral breast cancer. Eleven are deceased, four from breast cancer-all from metastasis. 12-year Kaplan-Meier estimates were: overall survival 78 ± 7 %, cause specific survival 93 ± 4 %, and recurrence-free survival 82 ± 6 %. Univariate analysis identified nodal disease as significant for cause specific survival (log rank p = 0.005). No ipsilateral breast recurrences were found. Early administered radiation and accurate boost localization were identified as suspected treatment-related factors for local recurrence. When these two treatment-related factors are minimized, long-term local control rates do not suffer.