Organ preservation in invasive bladder cancer: Brachytherapy, an alternative to cystectomy and combined modality treatment?

A feasibility study of utilizing a cadaveric training model for novel robotic bladder cancer brachytherapy techniques

PURPOSE

The current standard of care for muscle-invasive bladder cancer is neoadjuvant chemotherapy followed by radical cystectomy with lymph node dissection. Although this treatment provides therapeutic benefit, it is associated with notable morbidity. Bladder sparing techniques, such as concurrent chemo-radiation, are less invasive and prioritize organ preservation in individuals with invasive bladder cancer and offer comparable disease control. High-dose-rate brachytherapy is an emerging paradigm in the management of muscle-invasive bladder cancer. During high-dose-rate brachytherapy, radioactive sources are introduced to the area of the primary tumor through specialized catheters. The specific placement of brachytherapy catheters results in heightened effectiveness of the radiation treatment with less radiation damage to surrounding structures. For bladder-sparing therapies such as brachytherapy to rival radical cystectomy, these techniques need to be refined further by radiation oncologists.

PROCEDURE

One such modality for developing and practicing these techniques is the use of cadaveric models in innovation-focused clinical training facilities, which provide a simulated sterile surgical environment without the concern for extending intraoperative time.

FINDINGS AND CONCLUSIONS

The objective of this technical note is to demonstrate how clinical training facilities such as the Houston Methodist Institute for Technology, Innovation & Education are ideal for the development, testing, and training of novel brachytherapy techniques using cadaveric models. By utilizing a network of similarly innovative training centers, research and development of brachytherapy techniques can be expedited, and novel bladder-sparing treatment methods can be implemented as the standard of care for bladder cancer.

Pushing the Envelope: The Role of Radiation Therapy in Non-muscle-Invasive Bladder Cancer

The standard of care for non-muscle-invasive bladder cancer (NMIBC) is transurethral resection followed by risk stratified use of intravesical immune- or chemotherapy and for multifocal, recurrent and high grade disease, radical cystectomy with high rates of cure. Bladder preservation analogous to the trimodality therapy approach in muscle-invasive bladder cancer (MIBC) has not been adequately explored but the available data suggests that NMIBC is a radioresponsive malignancy and that in a proportion of patients bladder preservation would be possible. Combination modality with chemotherapy, hypoxia sensitisation, hyperthermia and immunotherapy are all approaches which have been shown effective. Unfortunately the quality of the available data is poor. Although there are many putative prognostic biomarkers for progression in NMIBC none have emerged in clinical use and there are none predictive for response to non-surgical treatment. This would be an important component of future large scale studies to evaluate the precise role of radiotherapy within a multimodality schedule for bladder reservation in NMIBC.

Systematic review and meta-analysis of radiation therapy for high-risk non-muscle invasive bladder cancer

INTRODUCTION

Radiation therapy (XRT) has been investigated as a possible treatment for high-risk non-muscle invasive bladder cancer (NMIBC) with the goal of bladder preservation, especially with the ongoing Bacillus Calmette-Guerin (BCG) shortage. Yet, little is known about the clinical efficacy and the quality of evidence supporting XRT for NMIBC. Herein, we performed a systematic review and meta-analysis to evaluate XRT in the treatment of patients with high-risk NMIBC.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, and Web of Science were searched for high-risk NMIBC (high grade T1, T1/Ta with associated risk features: carcinoma in-situ (CIS), multifocality, > 5cm in diameter, and/or multiple recurrences) treated with primary XRT. Outcomes evaluated were recurrence-free survival (RFS), cancer-specific-survival (CSS), overall survival (OS), and salvage cystectomy and progression to metastatic disease rates. A meta-analysis was performed to assess outcomes for XRT in NMIBC.

RESULTS

Overall,13 studies including 746 patients met the search criteria. The 5-year rates of RFS, CSS and OS were 54% (95% CI = 38% - 70%), 86% (95% CI = 80% - 92%), and 72% (95% CI = 64% - 79%). Notably, 13% of patients proceeded to salvage radical cystectomy and 9% developed metastatic disease. All studies were of poor quality, comprising single institution and retrospective studies with only one clinical trial.

CONCLUSION

XRT for high-risk NMIBC provides some degree of oncologic control, although distant progression was noted. In the setting of the low-quality evidence, a prospective clinical trial is needed to clearly define the risks and benefits of this approach.

[Organ-sparing treatment of bladder cancer]

BACKGROUND

Muscle invasive bladder cancer is a frequent disease in Germany. The accepted therapy of choice is radical cystectomy. Due to comorbidities, radical removal of the bladder is often associated with increased perioperative morbidity; therefore alternatives to a radical procedure should be offered.

OBJECTIVES

Overview and description of focal therapeutic concepts in muscle invasive bladder cancer to provide therapeutic alternatives for radical organ removal.

MATERIALS AND METHODS

Database research, analysis and discussion of clinical trials presenting therapeutic concepts for focal therapy in muscle invasive bladder cancer.

RESULTS

High-energy shock waves, high-intensity focused ultrasound and laser therapy are experimental concepts for muscle invasive bladder cancer. Transurethral resection and radiotherapy in combination with chemotherapy, where appropriate, are available as focal therapy in bladder cancer.

CONCLUSIONS

Cystectomy is the accepted therapy for muscle invasive bladder cancer. Several therapeutic procedures are available as focal therapy. In selected cases, focal therapy can offer an alternative therapy in muscle invasive bladder cancer.

The Curie-Da Vinci Connection: 5-Years' Experience With Laparoscopic (Robot-Assisted) Implantation for High-Dose-Rate Brachytherapy of Solitary T2 Bladder Tumors

PURPOSE

To report experience and early results of laparoscopic implantation for interstitial brachytherapy (BT) of solitary bladder tumors and the feasibility of a high-dose-rate (HDR) schedule.

METHODS AND MATERIALS

From December 2009 to April 2015, 57 patients with a T2 solitary bladder tumor were treated in Arnhem with transurethral bladder resection followed by external beam irradiation, applied to the bladder and regional iliac lymph nodes, 40 Gy in 20 fractions, 5 fractions per week, and within 1 week interstitial HDR BT, in selected cases combined with partial cystectomy and lymph node dissection. The BT catheters were placed via a transabdominal approach with robotic assistance from a Da Vinci robot after a successful initial experience with a nonrobotic laparoscopic approach. The fraction schedule for HDR was 10 fractions of 2.5 Gy, 3 fractions per day. This was calculated to be equivalent to a reference low-dose-rate schedule of 30 Gy in 60 hours. Data for oncologic outcomes and toxicity (Common Toxicity Criteria version 4) were prospectively collected.

RESULTS

These modifications resulted in an average postoperative hospitalization of 6 days, minimal blood loss, and no wound healing problems. Two patients had severe acute toxicity: 1 pulmonary embolism grade 4 and 1 cardiac death. Late toxicity was mild (n=2 urogenital grade 3 toxicity). The median follow-up was 2 years. Using cumulative incidence competing risk analysis, the 2-year overall, disease-free, and disease-specific survival and local control rates were 59%, 71%, 87%, and 82%, respectively.

CONCLUSIONS

The benefits of minimally invasive surgery for implantation of BT catheters and the feasibility of HDR BT in bladder cancer are documented. The patient outcome and adverse events are comparable to the best results published for a bladder-sparing approach.

Bladder preservation with brachytherapy compared to cystectomy for T1-T3 muscle-invasive bladder cancer: a systematic review

Purpose

Radical cystectomy currently is the treatment of choice in muscle-invasive bladder cancer. However, cystectomy is associated with considerable morbidity. Bladder sparing treatment consists of transurethral resection of the tumor (with or without partial cystectomy), external beam radiotherapy, and brachytherapy. The purpose of this study is to compare bladder preservation with brachytherapy to cystectomy by a systematic review.

Material and methods

A systematic review was conducted using PubMed electronic database. Article selection was done independently by two authors. Data were extracted on cause-specific survival and overall survival at 2, 5, and 10 years. Comparison of the two treatment modalities was done by a Weibull survival analysis with metaregression analysis and estimation of Hazard Ratio's (HR's) with 95% confidence intervals (CI).

Results

Large differences in tumor staging and tumor grading were found between cystectomy and bladder sparing series. The adjusted HR's for cause-specific survival and overall survival were 1.27 (95% CI: 1.15-1.40) and 0.85 (95% CI: 0.84-0.87), respectively for bladder sparing relative to radical cystectomy.

Conclusions

Robustness of the analysis is hampered by the retrospective character of the study and differences in patient characteristics. For selected cases, bladder sparing by brachytherapy leads to at least similar overall survival compared to radical cystectomy for muscle invasive bladder cancer.

The role of radiotherapy in bladder cancer

In this article we report on the current role of radiotherapy in the management of non-muscle invasive as well as in muscle invasive bladder cancer.
Radiotherapy seems to have no role in non-muscle invasive bladder cancer.
In muscle invasive bladder tumors, the role of radiotherapy is under investigation in view of new radiotherapy techniques and novel cytotoxic and biological agents.

Bladder function preservation with brachytherapy, external beam radiation therapy, and limited surgery in bladder cancer patients: Long-term results [corrected]

PURPOSE

To report long-term results of a bladder preservation strategy for muscle-invasive bladder cancer (MIBC) using external beam radiation therapy and brachytherapy/interstitial radiation therapy (IRT).

METHODS AND MATERIALS

Between May 1989 and October 2011, 192 selected patients with MIBC were treated with a combined regimen of preoperative external beam radiation therapy and subsequent surgical exploration with or without partial cystectomy and insertion of source carrier tubes for afterloading IRT using low dose rate and pulsed dose rate. Data for oncologic and functional outcomes were prospectively collected. The primary endpoints were local recurrence-free survival (LRFS), bladder function preservation survival, and salvage cystectomy-free survival. The endpoints were constructed according to the Kaplan-Meier method.

RESULTS

The mean follow-up period was 105.5 months. The LRFS rate was 80% and 73% at 5 and 10 years, respectively. Salvage cystectomy-free survival at 5 and 10 years was 93% and 85%. The 5- and 10-year overall survival rates were 65% and 46%, whereas cancer-specific survival at 5 and 10 years was 75% and 67%. The distant metastases-free survival rate was 76% and 69% at 5 and 10 years. Multivariate analysis revealed no independent predictors of LRFS. Radiation Therapy Oncology Group grade ≥3 late bladder and rectum toxicity were recorded in 11 patients (5.7%) and 2 patients (1%), respectively.

CONCLUSIONS

A multimodality bladder-sparing regimen using IRT offers excellent long-term oncologic outcome in selected patients with MIBC. The late toxicity rate is low, and the majority of patients preserve their functional bladder.

Brachytherapy after external beam radiotherapy and limited surgery preserves bladders for patients with solitary pT1-pT3 bladder tumors

BACKGROUND

Several French, Belgian and Dutch radiation oncologists have reported good results with the combination of limited surgery after external beam radiotherapy (EBRT) followed by brachytherapy in early-stage muscle-invasive bladder cancer.

PATIENTS AND METHODS

Data from 12 of 13 departments which are using this approach have been collected retrospectively, in a multicenter database, resulting in 1040 patients: 811 males and 229 females with a median age of 66 years, range 28-92 years. Results were analyzed according to tumor stage and diameter, histology grade, age and brachytherapy technique, continuous low-dose rate (CLDR) and pulsed dose rate (PDR).

RESULTS

At 1, 3 and 5 years, the local recurrence-free probability was 91%, 80% and 75%, metastasis-free probability was 91%, 80% and 74%, disease-free probability was 85%, 68% and 61% and overall survival probability was 91%, 74% and 62%, respectively. The differences in the outcome between the contributing departments were small. After multivariate analysis, the only factor influencing the local control rate was the brachytherapy technique. Toxicity consisted mainly of 24 fistula, 144 ulcers/necroses and 93 other types.

CONCLUSIONS

EBRT followed by brachytherapy, combined with limited surgery, offers excellent results in terms of bladder sparing for selected groups of patients suffering from bladder cancer.

Dosimetric evaluation of a novel high dose rate (HDR) intraluminal / interstitial brachytherapy applicator for gastrointestinal and bladder cancers

High dose rate (HDR) brachytherapy is one of the accepted treatment modalities in gastro-intestinal tract and bladder carcinomas. Considering the shortcoming of contact brachytherapy routinely used in gastrointestinal tract in treatment of big tumors or invasive method of bladder treatment, an intraluminal applicator with the capability of insertion into the tumor depth seems to be useful. This study presents some dosimetric evaluations to introduce this applicator to the clinical use. The radiation attenuation characteristics of the applicator were evaluated by means of two dosimetric methods including well-type chamber and radiochromic film. The proposed 110 cm long applicator has a flexible structure made of stainless steel for easy passage through lumens and a needle tip to drill into big tumors. The 2mm diameter of the applicator is thick enough for source transition, while easy passage through any narrow lumen such as endoscope or cystoscope working channel is ensured. Well-chamber results showed an acceptably low attenuation of this steel springy applicator. Performing absolute dosimetry resulted in a correlation coefficient of R = 0.9916 (p-value ≈ 10-7) between standard interstitial applicator and the one proposed in this article. This study not only introduces a novel applicator with acceptable attenuation but also proves the response independency of the GAFCHROMIC EBT films to energy. By applying the dose response of the applicator in the treatment planning software, it can be used as a new intraluminal / interstitial applicator.

Bladder cancer

PURPOSE OF REVIEW

To review the diagnosis and management of all stages of bladder cancer with an emphasis on studies and developments within the last year.

RECENT FINDINGS

Cystoscopy remains the mainstay in the detection and surveillance of bladder cancer, though fluorescent light may enhance detection as well as prolong recurrence-free survival. Urine cytology remains the gold standard for diagnosis and surveillance of bladder cancer; however, there are continued efforts in the development of urinary bladder cancer markers. Transurethral resection and instillation of perioperative chemotherapy remains the treatment of choice for superficial bladder cancer in most patients. Data supports the use of intravesical Bacillus Calmette-Guerin (including a maintenance regimen) for those at high risk for disease progression. Radical cystectomy with thorough pelvic lymphadenectomy remains the gold standard for management of muscle invasive disease. Research on the use of laparoscopy, robot-assisted laparoscopy, the effect on patient's health-related quality of life, and the potential role for bladder preservation strategies is ongoing. The value of neoadjuvant versus adjuvant chemotherapy around the time of cystectomy is still debated, though the best level-one evidence supports the use of neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin followed by cystectomy. Platinum-based chemotherapeutic agents are most commonly used in the community setting. Work is ongoing to develop new regimens, especially in patients who cannot take cisplatin. Research in the development of targeted therapies alone or in combination with chemotherapeutic regimens continues and will hopefully broaden our treatment strategy for patients with advanced/metastatic disease.

SUMMARY

We are encouraged by the progress in bladder cancer diagnosis and management; however, continued research is needed in order to improve the lives of our patients with this disease.

Radiochemotherapy for bladder cancer

Standard treatment for muscle-invasive bladder cancer is cystectomy. Multimodality treatment, including transurethral resection of the bladder tumour, radiation therapy, chemotherapy and deep regional hyperthermia, has been shown to produce survival rates comparable with those of cystectomy. With these programmes, cystectomy has been reserved for patients with incomplete response or local relapse. During the past two decades, organ preservation by multimodality treatment has been investigated in prospective series from single centres and co-operative groups, with more than 1000 patients included. Five-year overall survival rates in the range of 50-60% have been reported, and about three-quarters of the surviving patients maintained their bladder. Clinical criteria helpful in determining patients for bladder preservation include such variables as small tumour size (<5 cm), early tumour stage, a visibly and microscopically complete transurethral resection, absence of ureteral obstruction, and no evidence of pelvic lymph node metastases. On multivariate analysis, the completeness of transurethral resection of a bladder tumour was found to be one of the strongest prognostic factors for overall survival. Patients at greater risk of new tumour development after initial complete response are those with multifocal disease and extensive associated carcinoma in situ at presentation. Close co-ordination among all disciplines is required to achieve optimal results. Future investigations will focus on optimising radiation techniques, including all possibilities of radiosensitisation (e.g. concurrent radiochemotherapy, deep regional hyperthermia), and incorporating more effective systemic chemotherapy, and the proper selection of patients based on predictive molecular makers.

Brachytherapy versus cystectomy in solitary bladder cancer: a case control, multicentre, East-Netherlands study

PURPOSE

Comparing the outcome of surgery and brachytherapy-based radiotherapy in patients with solitary T1G3/T2 bladder tumour in, a retrospective case-control study, because efforts for a randomised clinical trial comparing these modalities have failed.

MATERIALS AND METHODS

Cystectomy group. Patients were selected using the pathological registration system (PALGA). 289 cases of TURT followed by cystectomy, indicated by a muscle--invading bladder tumour were performed in three East-Netherlands medical centres between 1991 and 2001. Out of this group 179 patients with clinical T2N0M0 bladder tumour were selected. All the consecutive files were analysed by a urologist and a radiation oncologist and 65 of those patients (mean age 63.7 years) would have been eligible for brachytherapy, based on an initial analysis: cystoscopy estimated tumour size, post-TURT pathological report, completed by CT-scan and/or, MRI-scan. A final pathological report after radical cystectomy was not considered for patients' selection. Brachytherapy group. Patients were selected using a prospective registration study aiming at determination of our treatment results. 89 Patients (mean age 68.4 years) underwent TURT followed by a course of external beam irradiation and interstitial brachytherapy from 1983 till 2005 in the Arnhem Radiotherapy Institute.

RESULTS

The median follow-up for the brachytherapy group was 5.7 years (range 0.2-21.4 years), for the cystectomy group was 5.05 years (range: 0.04-16.8 years). No difference in disease-specific survival (DSS) could be detected with a 5- and 10-year DSS of 71% and 66% in the brachytherapy group and 60% and 57% in the cystectomy group, respectively. Five-year overall survival (OS) was 57% in the brachytherapy group and 52% in the cystectomy group, however, the 10-year OS was better in the cystectomy than in the brachytherapy group (42% and 33%, respectively). This is caused by the significant age difference in favour of the cystectomy group. Cystectomy-free survival in the brachytherapy group was 70%.

CONCLUSION

Radical cystectomy is the treatment of choice for patients with muscle-invasive bladder carcinoma. However, in a selected patient population a bladder sparing treatment, i.e. a combination of transurethral tumour resection (TURT), external beam irradiation and interstitial brachytherapy, can be applied successfully. This concerns a solitary, T1G3 or T2 bladder tumour, with a diameter<5 cm.

Bladder cancer

PURPOSE OF REVIEW

This article will review the diagnosis and management of bladder cancer at each stage, from superficial to metastatic disease with an emphasis on recent developments over the last year.

RECENT FINDINGS

Bacille Calmette-Guerin is the most effective therapy for carcinoma in situ. All patients who receive intravesical therapy with bacille Calmette-Guerin should be considered for ongoing maintenance therapy. The management of muscle invasive disease in the United States centers on radical cystectomy with bilateral pelvic lymphadenectomy. Areas of research include the optimal role for bladder preservation therapy, a growing experience in centers with laparoscopy, the effect of urinary diversion on quality of life, and the optimal standard for pelvic lymphadenectomy at surgery. The role of combination chemotherapy for advanced bladder cancer continues to evolve. Many questions remain unanswered including the relative value of neoadjuvant versus adjuvant chemotherapy for locally advanced disease and optimal chemotherapy regimen.

SUMMARY

The detection of bladder cancer continues to rely on direct visualization with cystoscopy. Efforts are underway to improve the utility of urinary markers and cystoscopy through fluorescence endoscopy. The management of superficial bladder cancer is based on transurethral resection of the tumor with perioperative intravesical instillation of chemotherapy strongly suggested for most patients. Risk stratifying patients with high-risk superficial bladder cancer remain a challenge and area of future research.

Results of bladder-conserving treatment, consisting of brachytherapy combined with limited surgery and external beam radiotherapy, for patients with solitary T1-T3 bladder tumors less than 5 cm in diameter

PURPOSE

To evaluate the long-term, local relapse-free, distant metastasis-free, and overall survival rates in patients with a solitary bladder tumor <5 cm in diameter who were treated with external beam radiotherapy, limited surgery, and brachytherapy.

METHODS AND MATERIALS

The results of 122 patients after bladder-saving treatment were analyzed. After EBRT, the patients underwent cystotomy, and catheters were implanted. Of the 122 patients, 99 were treated with a continuous low-dose-rate technique and 23 patients with a pulsed-dose-rate technique. The median follow-up period was 5 years.

RESULTS

The 5-year local and distant relapse-free survival rate was 76% and 83%, respectively. The 5 and 10-year relapse-free survival rate was 69% and 66%, respectively. For overall survival, the corresponding rates were 73% and 49%. Toxicity was low. No differences were found between the continuous low-dose-rate and pulsed-dose-rate groups.

CONCLUSION

The results of our study have shown that external beam radiotherapy followed by brachytherapy as a bladder-saving treatment for a selected group of patients with bladder cancer yields excellent local tumor control and low toxicity.

Bladder cancer

PURPOSE OF REVIEW

This article reviews the diagnosis and management of bladder cancer with an emphasis on studies and developments over the past year.

RECENT FINDINGS

Cystoscopy remains the mainstay in the detection and surveillance of bladder cancer, though efforts continue in the development of urinary bladder cancer markers. Superficial bladder cancer continues to be managed predominantly through transurethral resection with perioperative instillation of chemotherapy recommended for most patients. Intravesical bacille Calmette-Guerin (including a maintenance regimen) should be used for those at high risk for progression. Muscle invasive disease continues to be managed by radical cystectomy. Research continues on the use of laparoscopy, the effect on patient's health-related quality of life, and the potential role for bladder preservation strategies. The role of neoadjuvant versus adjuvant chemotherapy around the time of cystectomy remains to be resolved. The mainstays of chemotherapy remain methotrexate, vinblastine, doxorubicin, and cisplatin, and gemcitabine and cisplatin, but work is ongoing to develop new regimens, especially in patients who cannot take cisplatin.

SUMMARY

Although great strides continue to be made each year in the diagnosis and management of bladder cancer considerably more work needs to be done in order to improve the lives of our patients with this disease.

A feasibility study of using gold seeds as fiducial markers for bladder localization during radical radiotherapy

Target localization and verification of the treatment position is important for the accurate delivery of conformal radiotherapy. The bladder in particular is a deformable structure whose shape and position continually varies throughout a course of radiation treatment as a result of bladder filling. We report a novel technique of organ localization using gold seeds as fiducial markers that are implanted into the bladder using a specially adapted applicator that is passed through a rigid cystoscope. The seeds are readily apparent on electronic portal imaging taken at the time of radiotherapy and can thus act as a surrogate for bladder position. The feasibility and technical aspects of performing such a procedure on eight patients were assessed. In all of the patients, some of the seeds were visible on the planning CT scan and remained within the bladder wall throughout the course of radiotherapy treatment. The drop-out rate was minimized by the use of cystodiathermy at the site of seed insertion. It was possible to place the seeds in both areas of normal and diseased bladder tissue. The procedure was associated with minimal toxicity. This technique will form the basis for planning further studies on bladder localization.

Trimodality Treatment and Selective Organ Preservation for Bladder Cancer

Standard treatment for muscle-invasive bladder cancer is cystectomy. Trimodality treatment, including transurethral resection of the bladder tumor (TURBT), radiation therapy and chemotherapy, has been shown to produce survival rates comparable to those of cystectomy. With these programs, cystectomy has been reserved for patients with incomplete response or local relapse. During the past 15 years, organ preservation by trimodality treatment has been investigated in prospective series from single centers and cooperative groups, with more than 1,000 patients included. Five-year overall survival rates in the range of 50% to 60% have been reported, and approximately three quarters of the surviving patients maintained their bladder. Clinical criteria helpful in determining ideal patients for bladder preservation include early tumor stage (including high-risk T1 disease), a visibly complete TURBT, and absence of ureteral obstruction. Close coordination among all disciplines is required to achieve optimal results. Future investigations will focus on (1) optimizing radiation techniques and incorporating more effective systemic chemotherapy, and (2) the proper selection of patients based on molecular makers.

Bladder-sparing approaches to invasive disease

Although immediate radical cystectomy remains the standard of care for invasive bladder cancer, a large body of international experience from single institutions and cooperative groups has accumulated, suggesting favorable results with bladder-sparing approaches in appropriately selected patients. Modern selective bladder preservation with trimodality therapy, consisting of transurethral resection of the bladder tumor, radiation, and chemotherapy, can achieve complete response rates of 60-80%, 5-year survival rates of 50-60%, and survival rates with an intact bladder of 40-45%. Although no randomized comparisons between cystectomy and trimodality therapy exist, long-term data confirm that the 10-year overall and disease-specific survival rates for patients in bladder-sparing protocols are comparable to outcomes reported in contemporary cystectomy series. In addition, quality of life studies have demonstrated that the retained native bladder functions well. Thus, trimodality therapy with careful cystoscopic surveillance and with prompt cystectomy for invasive recurrences has emerged as a legitimate alternative to extirpative surgery. Future work will continue to optimize the bladder-sparing regimen while limiting toxicity.

Evaluating the Effect of Reducing the High-dose Volume on the Toxicity of Radiotherapy in the Treatment of Bladder Cancer

AIMS

The radiation dose used to treat bladder cancer is limited by the risk of inducing severe late bladder toxicity. Retrospective data suggest that radiation tolerance is greater for partial rather than whole bladder irradiation. Limiting the high-dose region to a section of the bladder may reduce toxicity, opening the way for dose escalation. The aims of this study were to establish the efficacy and compare the late toxicity between (1) a two-phase technique limiting the high-dose area and (2) a conventional single-phase radiotherapy to the whole bladder.

MATERIALS AND METHODS

A cohort study was undertaken of 229 patients with invasive bladder cancer treated with computed tomography-planned radical radiotherapy at the Royal Marsden Hospital from 1984 to 1998. In total, 154 patients received a single-phase treatment to the whole bladder with a 2 cm margin. Seventy-five patients with solitary, well-localised tumours were selected for treatment using a two-phase technique. The first phase (12 Gy) aimed to treat the tumour with a 2 cm margin. A second phase treated the whole bladder with 52 Gy. One hundred and forty-one patients were planned to receive a dose of 60-64 Gy/30-32 fractions over 6-6.5 weeks, whereas 88 patients received an accelerated regime. Data on late bladder and bowel toxicity (using Radiation Therapy Oncology Group criteria) were collected prospectively at the annual review.

RESULTS

At the 5-year follow-up there was no difference in overall survival (hazard ratio = 0.91, 95% confidence interval 0.64-1.3) or failure-free survival (hazard ratio = 1.02, 95% confidence interval 0.73-1.43) between the two techniques. The two-phase reduced volume treatment was less toxic, with a 19% absolute reduction in overall grade 3-4 late toxicity (P = 0.02). These differences were more marked for bladder toxicity compared with bowel toxicity.

CONCLUSIONS

The two-phase reduced volume technique was associated with less bladder and bowel toxicity than conventional whole bladder radiotherapy without evidence of impaired survival.

X-ray volume imaging in bladder radiotherapy verification

PURPOSE

To assess the clinical utility of X-ray volume imaging (XVI) for verification of bladder radiotherapy and to quantify geometric error in bladder radiotherapy delivery.

METHODS AND MATERIALS

Twenty subjects undergoing conformal bladder radiotherapy were recruited. X-ray volume images and electronic portal images (EPIs) were acquired for the first 5 fractions and then once weekly. X-ray volume images were co-registered with the planning computed tomography scan and clinical target volume coverage assessed in three dimensions (3D). Interfraction bladder volume change was described by quantifying changes in bladder volume with time. Bony setup errors were compared from both XVI and EPI.

RESULTS

The bladder boundary was clearly visible on coronal XVI views in nearly all images, allowing accurate 3D treatment verification. In 93.5% of imaged fractions, the clinical target volume was within the planning target volume. Most subjects displayed consistent bladder volumes, but 25% displayed changes that could be predicted from the first three XVIs. Bony setup errors were similar whether calculated from XVI or EPI.

CONCLUSIONS

Coronal XVI can be used to verify 3D bladder radiotherapy delivery. Image-guided interventions to reduce geographic miss and normal tissue toxicity are feasible with this technology.

Radical radiotherapy for invasive bladder cancer: What dose and fractionation schedule to choose?

PURPOSE

To establish the alpha/beta ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes.

METHODS AND MATERIALS

Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED.

RESULTS

The estimated alpha/beta ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined.

CONCLUSION

With the clinical data currently available, a reliable estimation of the alpha/beta ratio for bladder cancer is not feasible. It seems reasonable to use a conventional alpha/beta ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer.

Survival after Bladder-Preservation with Brachytherapy versus Radical Cystectomy; A Single Institution Experience

OBJECTIVE

To evaluate the long-term survival following brachytherapy and following cystectomy of patients with invasive bladder cancer treated in our institution.

PATIENTS AND METHODS

Between 1988 and 2000 108 patients with solitary, organ confined T1-T2 invasive bladder cancer of < or = 5 cm were treated with a transurethral resection, and a course of external beam radiotherapy (30 Gy) followed by 40 Gy brachytherapy. The overall and disease specific survival rates of these patients are compared with those of 77 patients with T1-T2 invasive bladder cancer treated with cystectomy between 1988-2003.

RESULTS

The 5/10 year overall survival rates were 62%/50% after brachytherapy and 67%/58% after cystectomy (p = 0.67). The 5/10 year disease specific survival rates were 73%/67% after brachytherapy and 72%/72% after cystectomy (p = 0.28). When adjusted for age, multiplicity, T-stage, N-stage and grade, the 5/10 year overall survival rates were 65%/53% after brachytherapy and 62%/51% after cystectomy, respectively. The adjusted disease specific survival rates were 75%/70% after brachytherapy and 66%/66% after cystectomy.

CONCLUSIONS

This study does not provide evidence regarding survival against the use of bladder preservation with brachytherapy for patients with solitary, T1-T2 invasive bladder cancer of < or = 5 cm diameter, seeking bladder-sparing alternatives to radical cystectomy.