Cancer of the urinary bladder category T2, T3, (NxMo) treated by interstitial radium implant: second report

Perpetual role of brachytherapy in organ-sparing treatment for bladder cancer: a historical review

Brachytherapy-based radiotherapy has been applied for decades in the curative treatment for solitary, ≤ 5 cm bladder tumors. This review provides a historical perspective of this organ sparing approach.

A systematic search of the published literature between 1900 and 2019 was performed on the subject of bladder brachytherapy using PubMed, with digitally retrievable articles being supplemented with articles from the personal collection of the authors.

The articles were divided into consecutive time periods, each reflecting the impact of authors on the development of brachytherapy treatment: the time of pioneers, early innovators, modifiers, and recent innovators. Three case-controlled studies comparing brachytherapy-based organ-sparing treatment with cystectomy, demonstrated similarity between the two approaches in terms of disease-free and overall survival, whereas brachytherapy-based approach offered the advantage of at least 80% chance of bladder preservation. The overview was organized in a chronological order, starting from the evolution of brachytherapy from radium, followed by remote afterloading and dose-rate adjustments, and closing with modern era of high-dose-rate and image-guided brachytherapy. Importantly, we demonstrated how essential and beneficial for the patients is a close collaboration between radiation oncologists and urologists, and how adopting a modern surgical development, i.e. the laparoscopic implantation technique, which later became robot-assisted, contributed to the success of this multidisciplinary brachytherapy treatment.

We concluded that this highly effective brachytherapy method with very limited toxicity deserves more worldwide popularity.

Overall survival, disease-specific survival and local recurrence outcomes in patients with muscle-invasive bladder cancer treated with external beam radiotherapy and brachytherapy: a systematic review

INTRODUCTION

Neoadjuvant chemotherapy followed by radical cystectomy (RC) and pelvic lymph node dissection is the standard radical management for muscle-invasive bladder cancer (MIBC). However, major pelvic surgery is not suitable for all patients and combined modality therapy (CMT) offers an alternative for patients who want to retain their bladder. Brachytherapy (BT), as part of CMT, has been offered in selective cases of bladder cancer.

OBJECTIVES

To evaluate the clinical effectiveness of BT for solitary urinary bladder tumours in terms of survival, local recurrence (LR) rates, and adverse events.

METHODS

A systematic review was conducted using defined search terms using online databases. Articles that discussed the use of BT as part of multi-modality treatments for MIBC were included.

RESULTS

Searches returned 112 articles of which 20 were deemed suitable for analysis. In all, 15 of the 20 articles reported overall survival (OS) at 5 years, 2747 patients were at risk and 1670 were alive after 5 years (60%): seven studies reported OS at 10 years, with 817 patients at risk and 350 alive at 10 years (42%). Disease-specific survival at 5 years was reported in four studies, with 371 patients at risk and 279 alive (75%) at 5 years. LR rates were reported across all 20 studies and ranged from 0% to 32%.

CONCLUSION

Brachytherapy as part of CMT for MIBC is not a standard technique. It is an effective treatment in experienced centres for a selected patient population who wish to preserve their bladder. In such patients, CMT-BT is well tolerated with an acceptable safety profile.

Robot-assisted brachytherapy of the bladder with long distance support using video conferencing

PURPOSE

The frontline treatment for localized muscle-invasive bladder carcinoma (MIBC) is radical cystectomy. However, a significant percentage of this population is elderly with either severe co-morbidities or suboptimal general health, increasing the per- and post-operative risk when undergoing a radical cystectomy. Conservative treatment options have been implemented such as robot-assisted laparoscopic brachytherapy (RALB), a minimally invasive therapeutic approach ensuring excellent results in terms of local control, survival, and low morbidity. The treatment was supported successfully long distance using videoconferencing by an expert group from the Netherlands.

MATERIAL AND METHODS

An 81-year-old man was treated with RALB. The patient was submitted to external beam radiotherapy (EBRT) in a total dose of 40 Gy in 20 fractions. A partial cystectomy followed by implantation of three catheters along the scar and brachytherapy was completed. A total dose of 25 Gy in 10 fractions was administered with dose points calculated at 5 mm from the catheters.

RESULTS

Dose planning was characterized by an homogeneity index of 62.3% and overdose index of 19.7%. Other conformity indexes were analyzed. Patient was discharged at the fourth day after the procedure. The clinical response after 6 months was documented.

CONCLUSIONS

The previously reported good rates of tumor control and survival, and the excellent tolerance and low morbidity support RALB as a promising approach for selected groups of patients with localized MIBC. This case illustrates the ability to expand efficiently this technique, particularly among inexperienced medical teams.

Intraoperative radiotherapy in gynaecological and genito-urinary malignancies: focus on endometrial, cervical, renal, bladder and prostate cancers

Intraoperative radiotherapy (IORT) refers to the delivery of a single radiation dose to a limited volume of tissue during a surgical procedure. A literature review was performed to analyze the role of IORT in gynaecological and genito-urinary cancer including endometrial, cervical, renal, bladder and prostate cancers.

Literature search was performed by Pubmed and Scopus, using the words “intraoperative radiotherapy/IORT”, “gynaecological cancer”, “uterine/endometrial cancer”, “cervical/cervix cancer”, “renal/kidney cancer”, “bladder cancer” and “prostate cancer”. Forty-seven articles were selected from the search databases, analyzed and briefly described.

Literature data show that IORT has been used to optimize local control rate in genito-urinary tumours mainly in retrospective studies. The results suggest that IORT could be advantageous in the setting of locally advanced and recurrent disease although further prospective trials are needed to confirm this findings.

GEC-ESTRO/ACROP recommendations for performing bladder-sparing treatment with brachytherapy for muscle-invasive bladder carcinoma

The standard treatment for muscle-invasive bladder cancer (MIBC) is a radical cystectomy with pelvic lymph node dissection with or without neoadjuvant chemotherapy. In selected cases a bladder sparing approach is possible, for example a limited surgical excision combined with external beam radiotherapy and brachytherapy. To perform brachytherapy flexible catheters have to be implanted in the bladder wall. The implantation is done either by the open retropubic approach or the endoscopic surgical approach. The largest experience for brachytherapy is with low-dose rate and pulsed-dose rate, although some short-term experience with high-dose rate is also reported. The main advantage for this technique is the conservation of bladder function, with comparable local control rates as for cystectomy series in selected cases. The GEC-ESTRO/ACROP (Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology / Advisory Committee on Radiation Oncology Practice) recommendations to perform bladder implantations and brachytherapy as a treatment option for MIBC are described.

A note from history: Landmarks in history of cancer, part 7

In the 2 and half decades reviewed (1970-1995), research established that chromosomal translocation, deletion, and DNA amplification are prerequisites to cancerogenesis and that oncogenes, tumor-suppressor genes, growth factors, and cytokines play crucial roles in the pathomechanism of cancer. Human papillomavirus, human immunodeficiency virus, herpes virus, and hepatitis B virus were identified as cancer-causing viruses. Several laboratory tests were developed for the detection of primary and recurrent cancers, and cancer prevention by screening methods was popularized. Sonography, computerized tomography, magnetic resonance imaging, positron emission tomography, excision of sentinel lymph nodes, and immunohistochemical techniques became routine procedures. Clinicopathologic staging and classification of tumors were standardized. Limited surgery, adjuvant and neoadjuvant chemoradiation, and the therapeutic use of monoclonal antibodies, tumor vaccines, and targeted chemotherapy became routine practice. The decline in cancer incidence and mortality demonstrated that cancer prevention and advancement in oncology are pivotal to success in the crusade against cancer. Above all, it was clearly established that the care of patients with cancer can be accomplished best in a multidisciplinary setting involving surgical oncologists, radiologists, radiation therapists, medical oncologists, surgical pathologists, and laboratory scientists. In conclusion, the 25 years from 1970 and 1995 are the high-water mark in clinical oncology, and this is the period when oncology turned from art to science.

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.

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.

Radiotherapy for Bladder Cancer

The radiotherapy panel met to develop international consensus about the optimal use of radiotherapy, alone or in combination with surgery and chemotherapy, in the radical treatment of patients with bladder cancer. A consensus meeting of experts in the treatment of bladder cancer was convened by the Société Internationale d'Urologie (SIU). The radiotherapy committee, which had international representation from 6 countries, performed a critical review of the English-language literature and developed evidence-based guidelines for the use of radiotherapy in the treatment of patients with bladder cancer. The strength of the evidence supporting each recommendation was ranked according to a 4-point scale. Consensus statements were developed that address (1) the effectiveness of radiotherapy in the treatment of bladder cancer, (2) the most appropriate patients for curative treatment with radiotherapy, (3) the optimal method of delivery of radiotherapy, (4) the best radiation prescription for treating bladder cancer, and (5) optimal management of the patient's condition after radiotherapy has been provided. Radiotherapy is effective treatment for selected patients with bladder cancer; it produces long-term disease control with preservation of normal bladder function. Modern radiotherapy treatment techniques offer the potential to improve cure rates and reduce adverse effects. All patients in whom the condition is newly diagnosed should be assessed in a multidisciplinary setting, where the relative merits of surgery, radiotherapy, and chemotherapy can be considered on an individual basis with the aim of optimizing overall outcomes.

Radiation Therapy for Muscle-invasive Bladder Cancer: Treatment Planning and Delivery

Radiation therapy allows organ preservation therapy in selected patients with muscle invasive bladder cancer. This review sets out to explore the role of radiation therapy in the management of muscle invasive bladder cancer. It describes and assesses the potential benefits provided by technological advances in radiation delivery in optimizing the therapeutic ratio.

Conformal radiotherapy of urinary bladder cancer

Recent advances in radiotherapy (RT) are founded on the enhanced tumour visualisation capabilities of new imaging modalities and the precise deposition of individualised radiation dose distributions made possible with the new systems for RT planning and delivery. These techniques have a large potential to also improve the results of RT of urinary bladder cancer. Major challenges to take full advantage of these advances in the management of bladder cancer are to control, and, as far as possible, reduce bladder motion, and to reliably account for the related intestine and rectum motion. If these obstacles are overcome, it should be possible in the near future to offer selected patients with muscle invading bladder cancer an organ-sparing, yet effective combined-modality treatment as an alternative to radical surgery.

Bladder-conserving surgery and interstitial brachytherapy for lymph node negative transitional cell carcinoma of the urinary bladder: results of a 28-year single institution experience

BACKGROUND AND PURPOSE

We retrospectively analyzed results for lymph node negative transitional cell carcinoma of the bladder treated with brachytherapy.

PATIENTS AND METHODS

From 1975-2002, 58 patients received preoperative external irradiation, partial cystectomy (in 69%), iliac node dissection, and iridium-192. Pathologic stage was: 10 pT1, 41 pT2, and 7 pT3. A median total brachytherapy dose of 60 Gy was delivered to the tumor bed.

RESULTS

Mean follow-up was 76 months (range, 0.5-296). Tumor stage significantly impacted cause-specific and disease-free survival (P=0.02). Eight pT1 patients were free of disease and 2 died of other cause. For pT2 patients, 5-year cause-specific and overall survival rates were, respectively, 70% (CI 95%: 53-87) and 60% (CI 95%: 43-77). Three pT3 patients died of cancer. For the pT2 patients, the probability of 5-year local control was 65% (CI 95%: 47-83) and being alive without disease with a functional bladder, 50% (CI 95%: 33-67). Previous transurethral resection (TUR) increased the bladder relapse risk among pT2 patients (P=0.03). Twelve patients had severe acute complications and 5 had severe late effects. A high dose of external irradiation increased risk of late complications (P=0.01). Most complications occurred in patients treated before 1985.

CONCLUSIONS

Highly select patients presenting with pT2 tumors less than 5 cm with no history of previous TUR may be successfully treated with low-dose external irradiation, limited partial cystectomy, and interstitial brachytherapy. High-risk pT1 patients may also benefit. Postoperative complications and late side effects are minimized with modern management. We recommend lifelong cystoscopic surveillance, with prompt surgical salvage for recurrence.

Radiotherapy for muscle-invasive carcinoma of the bladder: results of a randomized trial comparing conventional whole bladder with dose-escalated partial bladder radiotherapy

PURPOSE

To investigate whether delivering an increased radiation dose to the tumor-bearing region of the bladder alone would improve local disease control without increasing treatment toxicity.

METHODS AND MATERIALS

A total of 149 patients with unifocal T2-T3N0M0 bladder carcinoma were randomized between whole bladder conformal radiotherapy (WBRT, 52.5 Gy in 20 fractions, n = 60) and partial bladder conformal RT (PBRT) to tumor alone with 1.5-cm margins within either 4 weeks (PBRT4, 57.5 Gy in 20 fractions, n = 44) or 3 weeks (PBRT3, 55 Gy in 16 fractions, n = 45). The response was assessed cystoscopically after 4 months.

RESULTS

The 5-year overall and CFS rate was 58% and 47%, respectively, for the whole population. The CR rate was 75% for WBRT, 80% for PBRT4, and 71% for PBRT3 (p = 0.6), with a 5-year local control rate of 58%, 59%, and 34%, respectively (p = 0.18). Solitary new tumors arose within the bladder, outside the irradiated volume, in 6 (7%) of 89 patients who underwent PBRT. The 5-year overall survival and cystectomy-free survival rate was 61% and 49% for WBRT, 60% and 50% for PBRT4, and 51% and 41% for PBRT3 (p = 0.81 and p = 0.59). The treatment toxicity was mild and equivalent across the three trial arms.

CONCLUSION

The reduction in treatment volume allowed delivery of an increased radiation dose without a reduction in local tumor control or the development of excess toxicity. However, this dose-escalated partial bladder approach did not result in significantly improved overall survival.

Saving bladders with brachytherapy: implantation technique and results

PURPOSE

To analyze and report the treatment results of brachytherapy for solitary bladder cancer in the Arnhem Radiotherapy Institute.

METHODS AND MATERIALS

Between January 1983 and October 1998, 63 patients with a solitary bladder tumor were treated with a combination of transurethral resection, external beam radiotherapy (EBRT), and interstitial radiotherapy. The indications for bladder-conserving treatment were tumor < or =5 cm, T1G3 (n = 14), T2G2 (n = 8), T2G3 (n = 37), and T3a (n = 4). The prescribed implant dose was either 55 Gy (range 50-65 Gy) in combination with small pelvis external beam RT, 3-4 fractions of 3.5 Gy (n = 58), or 30 Gy in combination with 20 fractions of 2 Gy external beam radiotherapy (n = 5). Brachytherapy was performed with 2-8 137Cs needles until 1995 (n = 48) and 2-5 afterloading catheters (192Ir) since 1996 (n = 15). Follow-up cystoscopies were performed at 3-month intervals during the first 2 years, then every 6 months for 3 years, and annually after the fifth year. The median follow-up was 4.9 years.

RESULTS

Twenty patients developed local recurrences, of which 6 were "true in-implant recurrences," 12 were in second bladder locations, and 2 were urethral recurrences. All recurrences developed within 2.5 years after treatment. Of these 20 patients, 13 underwent cystectomy: 6 stayed disease-free, 1 died of postoperative complications, 2 developed regional metastases, and 4 developed distant metastases. The 5-year disease-specific survival rate was 80% for patients with Stage T1 and 60% for those with Stage T2 disease. The local control rate was 70% in the whole patient population and 80% after salvage cystectomy. Forty-four bladders were saved. Acute complications were seen in 14 patients, and no significant late complications occurred.

CONCLUSION

Using this treatment technique, a high cure rate with conservation of the bladder and only minor toxicity can be obtained in a selected patient population having a solitary tumor < or =5 cm.

Prevention of implantation metastases after resection of proximal bile duct tumours with pre-operative low dose radiation therapy

AIMS

Pre-operative endoscopic retrograde cholangiopancreatography (ERCP) with biliary drainage is associated with a greater risk of implantation metastases after resection of proximal bile duct tumours. In a previous study among patients who had undergone biliary drainage before resection, eight patients (20%) developed implantation metastases, within 1 year following resection. The aim of this analysis was to evaluate the results of pre-operative irradiation with regard to a possible reduction of implantation metastases.

METHODS

Twenty-one patients with proximal bile duct tumours who had undergone resection following pre-operative irradiation were retrospectively analysed. Pre-operative radiation therapy consisted of three fractions of 3.5 Gy external beam irradiation of the hilar area.

RESULTS

Pre-operative biliary drainage was performed in 19 patients (90%). All patients received pre-operative radiotherapy during which no complications were noted. None of the patients developed implantation metastases within a follow-up time of 2 to 79 months.

CONCLUSION

The results of this study suggest that pre-operative radiotherapy in patients with a resectable proximal bile duct tumour who have undergone pre-operative drainage, decreases the risk of implantation metastases. To be certain about the role of pre-operative radiotherapy, a randomized study is required. Until then, we advocate standard low dose radiotherapy preceding resection in all patients with lesions suggestive of a proximal bile duct tumour who have undergone biliary drainage.

[Late effects of radiations on the bladder]

Clinical effects of radiation on bladder are in relation with their effects on various tissus of this organ. The most important is the vessels. According to clinical models; it is possible to evaluate the different factors, especially the dose and the irradiated volume. The risk of complications rise with these two factors. Drugs used in bladder cancer don't seem to increase the risk of complications. The prevention of the late effects lies on the tissue protection and on the precise evaluation of the irradiated volume in view to reduce them.

Muscle invasive bladder cancer treated by transurethral resection, followed by external beam radiation and interstitial iridium-192

PURPOSE

To evaluate the results of transurethral resection (TUR), external beam radiotherapy (EBRT), and interstitial radiation (IRT) with iridium-192, using the afterloading technique in patients with muscle invasive bladder cancer.

METHODS AND MATERIALS

From May 1989 until September 1995, 66 patients with primary, solitary muscle invasive bladder cancer were treated with TUR, EBRT, and IRT, aiming at bladder preservation. According to the protocol, in three patients low-dose EBRT was applied, whereas 63 patients received high-dose EBRT. Immediately prior to IRT, 42 patients underwent a lymphnode dissection, and in 16 cases a partial cystectomy was performed. For IRT, two to five catheters were used and IRT was started within 24 h after surgery. The majority of patients received 30 Gy of IRT, with a mean dose rate of .58 Gy/h. In three patients, additional EBRT was applied following IRT. Follow-up consisted of regular cystoscopies, mostly done during joint clinics of urologist and radiation oncologist, with urine cytology routinely performed. The median follow-up period was 26 months. The Kaplan-Meier method was used for the determination of survival rates.

RESULTS

In seven patients, a bladder relapse developed. The probability of remaining bladder relapse free at 5 years was 88%. The bladder was preserved in 98% of the surviving patients. Metastases developed in 16 patients, and the probability of remaining metastasis free at 5 years was 66%. The cumulative 5-year overall and bladder and distant relapse free survival were 48% and 69%, respectively. Acute toxicity was not serious in the majority of cases; surgical correction of a persisting vesicocutaneous fistula was necessary in two patients, whereas a wound toilet had to be performed in another patient. Serious late toxicity (bladder, RTOG Grade 3) was experienced by only one patient.

CONCLUSIONS

Interstitial radiation preceded by TUR and EBRT, in a selected group of patients with muscle invasive bladder cancer, yields an excellent bladder tumor control rate with a high probability of bladder preservation. Survival was mainly dependent on the development of distant metastases. Serious acute and late toxicity was rare.

Invasive bladder cancer: treatment strategies using transurethral surgery, chemotherapy and radiation therapy with selection for bladder conservation

PURPOSE

Combined modality therapy has become the standard oncologic approach to achieve organ preservation in many malignancies.

METHODS AND MATERIALS

Although radical cystectomy has been considered as standard treatment for invasive bladder carcinoma in the United States, good results have been recently reported from several centers using multimodality treatment, particularly in patients with clinical T2 and T3a disease who do not have a ureter obstructed by tumor.

RESULTS

The components of the combined treatment are usually transurethral resection of the bladder tumor (TURBT) followed by concurrent chemotherapy and radiation therapy. Following an induction course of therapy a histologic response is evaluated by cystoscopy and rebiopsy. Clinical "complete responders" (tumor site rebiopsy negative and urine cytology with no tumor cells present) continue with a consolidation course of concurrent chemotherapy and radiation. Those patients not achieving a clinical complete response are recommended to have an immediate cystectomy. Individually the local monotherapies of radiation, TURBT, or multidrug chemotherapy each achieve a local control rate of the primary tumor of from 20 to 40%. When these are combined, clinical complete response rates of from 65 to 80% can be achieved. Seventy-five to 85% of the clinical complete responders will remain with bladders free of recurrence of an invasive tumor.

CONCLUSIONS

Bladder conservation trials using combined modality treatment approaches with selection for organ conservation by response of the tumor to initial treatment report overall 5-year survival rates of approximately 50%, and a 40-45% 5-year survival rate with the bladder intact. These modern multimodality bladder conservation approaches offer survival rates similar to radical cystectomy for patients of similar clinical stage and age. Bladder-conserving therapy should be offered to patients with invasive bladder carcinoma as a realistic alternative to radical cystectomy by experienced multimodality teams of urologic oncologists.

Modern brachytherapy: current state and future prospects

This article reviews the current trends and future developments in brachytherapy. Established techniques including interstitial and high-dose rate brachytherapy are discussed with particular reference to lung, oesophageal, cervical and endometrial cancer. Intra-operative high-dose rate brachytherapy and other new techniques are also mentioned.

A feasibility study of high dose rate brachytherapy in solitary urinary bladder cancer

PURPOSE

To determine the feasibility of high dose rate brachytherapy in the treatment of T1-T3 solitary bladder cancer and to compare results and side-effects to those obtained by others using conventional, i.e., low dose rate regimens.

METHODS AND MATERIALS

Between July 1992 and 1995, 16 patients entered the study. Median age at diagnosis was 64 years (range: 45-79 years). Diagnostic transurethral resection showed four T1, five T2, and seven T3 lesions, all proven solitary by random biopsies. Radiotherapy consisted of low-dose preoperative external beam irradiation (3 x 3.5 Gy on the 3 consecutive days prior to implantation), followed by high dose rate brachytherapy (15 x 3 Gy during the 8 consecutive days thereafter). Median follow-up from the date of implantation was 23 months (range: 6-43 months). In 15 patients, cystoscopy was systematically performed during follow-up, whereas the 16th patient was followed on a clinical basis only.

RESULTS

Recurrences have occurred in 2 of 15 evaluable patients (both stage T3): metastasis in 1 and combined local plus distant failure in the other patient. Cystoscopic evaluation showed persisting alterations of the implanted portion of the bladder mucosa in 11 of 15 evaluable patients (ulceration, calcifications, and/or punctiform bleedings). Symptomatic radiation cystitis was mild and transient in 14 but persisting and severe in 2 patients.

CONCLUSION

This study documents the feasibility of high dose rate brachytherapy in a selected group of bladder cancer patients. Both patient outcome and side-effects are comparable to the best results obtained with low dose rate schedules. Additional follow-up is still needed to enforce the comparison.

Opportunities with combined modality therapy for selective organ preservation in muscle-invasive bladder cancer

Combined-modality therapy for organ preservation represents an appropriate alternative to radical surgery in the management of several malignant diseases. The standard therapy for muscle-invasive bladder cancer in the United States has been radical cystectomy. Although the sequelae of radical surgery have been ameliorated somewhat by techniques for the construction of orthotopic bladders, the ideal therapy should both cure the patient of cancer and maintain a functioning natural bladder. Years of experience in Europe and Canada with bladder preservation using radiation therapy are documented. Advances in transurethral surgery technique and in the combination of radiation and chemotherapy have led to safe and effective regimens for patients with bladder cancer. Several recent trials with combined-modality therapy have established this treatment as a viable alternative to radical cystectomy in selected patients.

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.

The response of the urinary bladder, urethra, and ureter to radiation and chemotherapy

A comprehensive review of the physiological and clinical response of the urinary bladder, ureter, and urethra to radiation and chemotherapy is presented. The clinical syndromes that follow therapy for cancer of the bladder, prostate, and cervix are reviewed in detail. Methods of assessing, scoring, and managing toxicity are discussed.

Brachytherapy: criteria for case selection

Brachytherapy has an established role in the management of a number of malignancies. Contributing to successful application of brachytherapy techniques are proper planning, technical sophistication, and meticulous execution. Equally important, presumably, is proper case selection although conditions favoring brachytherapy utilization are not well described. To facilitate discussion of this topic, a semiquantitative system of brachytherapy case selection is proposed. Variables considered include the natural history of the malignancy, risks involved in the procedure, accessibility of implant site, and results obtainable with other treatment modalities. Brachytherapy Case Selection Scores (0-8) were generated for a number of malignancies. Higher scores were found for sites in which the use of brachytherapy is generally accepted and practiced, implying that the clinical factors considered in this system are clinically relevant, and that such a system could be useful when considering the use of brachytherapy in individual cases. Additional critical analysis regarding brachytherapy case selection is desirable.

Bladder conservation in selected T1G3 and muscle-invasive T2-T3a bladder carcinoma using combination therapy of surgery and iridium-192 implantation

OBJECTIVE

To retrospectively analyse the efficacy and toxicity of conservative treatment for T1G3 and T2-3a bladder carcinoma and to compare the results with those obtained in a previous study using caesium implantation.

PATIENTS AND METHODS

Between 1987 and 1990 12 patients with high-grade T1 tumours and 28 with T2-3a tumours were treated using this combined approach. All tumours were solitary with a diameter not exceeding 5 cm. Treatment consisted of transurethral resection, a course of external irradiation (30 Gy in 15 fractions) to the whole pelvis and an implant procedure.

RESULTS

With a mean follow-up of 40 months (range 24-65) 31 patients remained free of disease and nine relapsed: three with distant metastases, two with bladder recurrence and four with combined bladder and distant relapse. Three patients showed tumour at the original site. The 5 years actuarial rate of local control was 84% with an overall 5 years actuarial survival of 86%. Early problems included bladder leakage, wound infection and psychological problems. Late complications in four patients, was transient ulceration at the implant side causing mild dysuria.

CONCLUSIONS

Implantation with iridium is equally effective as with caesium but has significantly fewer complications.

Radical treatment for primary bladder cancer: where are we and where do we go from here? A review

The management of the primary tumour in muscle-invasive bladder cancer is determined more by geographical location than by firm evidence of the superiority of either surgery or radiotherapy over the other. Recent technological advances in both specialties may change their acceptability and efficacy, but as yet none has been fully evaluated. The effect of chemotherapy on primary tumour control may also influence management choices. There is a need to reexamine the merits of surgery and radiotherapy in the modern era.

Treatment of T3a bladder cancer with iridium implantation

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

Bladder cancer. Advances in laboratory innovations and clinical management, with emphasis on innovations allowing bladder-sparing approaches for patients with invasive tumors

In the present decade important progress has been made in the understanding of the biology and management of bladder cancer. Experimental laboratory models and new investigative tools have revealed potentially important prognostic markers and have led to an improved understanding of the histogenesis of the disease. Advances in the management of superficial bladder cancer (intravesical chemotherapy or immunotherapy, improved urinary cytology, laser technology, flexible fiberoptic cystoscopy, and photodynamic therapy) have, in some subgroups, improved tumor control while decreasing patient complications. For invasive bladder cancer (invasive of bladder muscle or beyond) improved techniques of cystectomy and radiotherapy have reduced the complications of treatment and may have contributed small but important improvements in cure. A major improvement in the last decade has occurred in objective remission rates with chemotherapy for patients with metastatic bladder cancer. From 20% to 40% of patients achieve a complete remission, and 10% to 20% may survive for more than 3 years. Randomized Phase III trials are currently in progress and must be completed to define the true role of multidrug chemotherapy in patients with metastatic disease and to validate data from the regimens of cyclophosphamide, methotrexate, and vincristine (CMV) and methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) before any of these approaches to treatment can be considered of proven benefit. Preliminary data from the Massachusetts General Hospital are presented of a potentially effective approach to select patients with invasive tumor for successful bladder preservation. In this approach transurethral debulking surgery is combined with upfront CMV chemotherapy plus cisplatin and 4000 cGy. If tumor is found on cystoscopic reevaluation with biopsy and cytology immediately following cisplatin and 4000 cGy, cystectomy is performed; if not, consolidation by a radiation boost to 6480 cGy plus cisplatin is given. The approach is fairly well tolerated, allows cystectomy without undue complications, has yielded a 88% complete response rate in patients selected for bladder preservation, and resulted in 90% of patients free of distant metastases with follow-up ranging from 6 to 30 months. A randomized Phase III trial with and without neoadjuvant MCV chemotherapy for selective bladder preservation is now under way and accruing well.

Carcinoma of the urinary bladder category T2,3NXM0 treated by 40 Gy external irradiation followed by cesium137 implant at reduced dose (50%)

Forty-eight bladder cancers T2NXM0 with bad prognostic factors and 42 T3NXM0 growths, suitable for interstitial treatment, were submitted to 40 Gy external irradiation immediately followed by Cae137 Implant at "reduced dose". Intercurrent death corrected 5-year survival for both groups was about 80%. The influence of previously identified bad prognosticators (more than one TUR, WHO grade 3, 4, vascular invasion in the biopsy specimen, pathological IVP) was nearly eradicated.

Treatment alternatives for invasive bladder cancer

Radical cystectomy remains the gold standard in the treatment of patients with muscle invasive bladder cancer. However, the specter of high failure rates coupled with morbid treatment methods has caused urologists, oncologists, and radiotherapists to explore modifications in, and alternatives to, the traditional treatments for invasive bladder cancer. The identification of the active methotrexate-platinum-based combination chemotherapy regimens heralds a new era in our ability to treat advanced disease effectively. Patients with less extensive muscle invasive tumors may be efficiaciously treated using conservative surgical excision, either alone or in combination with adjunctive treatments. In addition, definitive radiation therapy, given via the interstitial route or in combination with radiosensitizers, may result in long-term survival and preservation of bladder function. Progress has been made on multiple fronts in our ability to improve overall survival rates while allowing for the preservation of bladder function. The ability of these new mixed multimodality treatment initiatives to produce viable statistics equal to that of radical exenteration is an important landmark on the route towards an ideal treatment for invasive bladder cancer.

Conservative treatment of bladder carcinoma by partial cystectomy and interstitial iridium 192

From 1971 to 1984, 85 patients with bladder carcinoma were treated conservatively at the Henri Mondor Hospital by a combination of short course of pre-operative external pelvic irradiation, iliac node dissection, partial cystectomy, and iridium 192 implantation. There were 79 transitional cell carcinomas (G1: 12, G2: 25, G3: 36, Gx: 6) and 6 squamous cell carcinomas. By clinical stage, based on endoscopic resection, there were 43 T1, 30 T2, 5 T3, and 7 Tx. After partial cystectomy the pathologic stage distribution was: 41 pT1, 31 pT2, and 13 pT3. Crude disease-free survival at 5 years is 72% for T1 tumors and 55% for T2, but overall only 16% of patients died of bladder carcinoma. Local failures were seen in 11.5% of T1 and 0% of T2 tumors, and second bladder tumors developed at a distance from the treated site in 11.5% of T1 and 7% of T2. There is a non significant trend for intravesical recurrences (both local failures and second tumors) to occur more frequently for G1 tumors (25%) than for G2 (16%) or G3 (7%). At 5 years 95% of disease-free survivors have a functioning bladder. Regional or distant metastases occurred in 54% of patients with pT3 tumors and 10% of those with pT1 or pT2; within each stage there was no apparent influence of grade on metastatic risk. The four patients with histologically positive iliac nodes received additional post-operative external pelvic irradiation; three died of metastases and one is disease free at 10 years. No abdominal scar recurrences were seen. Late complications occurred in 6% of the population. For T1 tumors we suggest modification of the described protocol, eliminating the pre-operative irradiation and the lymph node dissection. If there is no doubt as to the pathologic stage after complete endoscopic resection, iridium 192 implantation delivering a dose of 60 Gy, without partial cystectomy, may be sufficient management. By contrast, for T2 tumors, all elements of the protocol seem important to obtain optimal results.

Discrepancies in dose and dose specification in interstitial implants

The first step in the execution of an interstitial implant is the decision on size and location of the target volume. Several implant systems, e.g. the Paterson-Parker system and the Paris system, give instructions for the optimal arrangement of sources to assure that the planned target volume is adequately covered. They also give guidelines to calculate the reference dose rate encompassing the planned target volume. These systems provide different solutions for the source arrangement for the same planned target volume, and vice versa, resulting in different reference dose rates. The problem of dose specification is discussed. For a number of theoretical implants predicted reference dose rates for the planned target volume were compared with the computer calculated dose rates for that volume. Discrepancies increase when moderate digressions from the adopted implant system rules are allowed, such as could commonly occur clinically. For a number of examples the degree of change in dose rate, if over 10%, and the position where this deviation is likely to occur are described. For optimal results the clinician should be well aware of these variations.

Treatment of bladder cancer with interstitial iridium-192 implantation and external beam irradiation

Although interstitial implantation of invasive carcinoma of the bladder has been shown to be an effective treatment in Europe, there has been little experience with this method in the U.S. During the past 6 years, 14 patients at the Hospital of the University of Pennsylvania with single bladder tumors less than 5 cm and no evidence of carcinoma in situ on random bladder biopsies have been treated by a combination of external beam radiation and iridium wire implant. The iridium wire is inserted by an afterloading technique following tumor exposure via suprapubic cystotomy. Following delivery of the prescribed dose, the sources are removed percutaneously. Three patients with recurrent or high grade T1 lesions and 11 patients with T2-T3A lesions have been treated. With a median follow-up of 22 months (range 17 to 65 months), 9 patients are currently NED, 4 patients have died of disease, and 1 patient has died of intercurrent disease. There have been two isolated bladder recurrences, both non-invasive, one having been treated with cystectomy and one being treated locally. In addition, one patient developed regional failure, two developed distant metastases only, and one developed local recurrence following distant failure. The 2-year actuarial local control rate is 84%, with an overall 2-year actuarial survival of 66%. Complications have been minimal. Bladder implantation by this method is technically simple and produces excellent local control with acceptable morbidity.

A comparison of preoperative radiotherapy regimens for bladder carcinoma. The University of Pennsylvania experience

Between 1976 and 1985, 155 patients from the Hospital of the University of Pennsylvania, the Philadelphia Veterans Administration Hospital, and the Fox Chase Cancer Center were divided into groups, each of which was treated with one of three preoperative radiotherapy regimens to be followed by cystectomy. Patients initially were treated with 4000 cGy during 4 weeks followed by cystectomy (16 patients). Beginning in 1978, patients received 2000 cGy in 1 week prior to surgery (70 patients). Since 1982, 40 patients were treated with 500 cGy on the day prior to surgery with postoperative radiation therapy reserved for patients with either involved margins of resection, advanced stage or high grade. A fourth group of 20 patients was either not offered or refused preoperative radiation. Nine patients received only postoperative radiation therapy. The 5-year actuarial disease-free survival for pathologic Stages B2, C, and D lesions (T3-4, N0-2), was 63% for those who had received high-dose radiation versus 21% for those that had low-dose or no radiation. Patients with advanced pathologic stage disease who had received greater than 2000 cGy had a reduced rate of local failure (11% versus 27% for those who had received less treatment). Patients with abnormal upper tracts as shown on the intravenous pyelograms (IVP) had a reduced 5-year determinate survival of 23% versus 65% for patients with normal upper tracts. This condition did not independently affect survival, but rather reflected advanced stage. Patients with abnormal creatinine levels had a decreased survival that was independent of stage. Computed tomography was found to have low sensitivity for determining extravesical extension (39%) and metastatic lymphadenopathy (12%). Patients with clinical Stage B2 and C disease (T3) that were downstaged had a 63% 5-year survival versus 18% of those that were not downstaged. The incidence of both ureteroenteral strictures and stomal complications was found to be higher in the 2000 cGy group than in those patients treated with the other regimens. The overall incidence of complications in that group was also significantly greater. We conclude that there is a continuing role for adjuvant radiotherapy in invasive bladder carcinoma to improve both pelvic control and survival. The 500 cGy radiotherapy "sandwich" regimen was equal in terms of pelvic control and survival to the other regimens and showed less overall morbidity. The 2000 cGy regimen was associated with the greatest incidence of morbidity and did not substantially improve pelvic control.

Intraoperative radiation therapy in patients with bladder cancer. A review of techniques allowing improved tumor doses and providing high cure rates without loss of bladder function

Conventional external beam irradiation, using modern megavoltage techniques and doses that do not harm bladder function, will permanently eradicate local bladder cancer in 30% to 50% of patients, compared with 70% to 90% with cystectomy. In appropriately chosen patients, open surgery can safely provide excellent exposure for the selective delivery of more radiant energy directly to the tumor and less to the uninvolved portion of the bladder. Intraoperative radiation therapy, by either a removable radium or iridium implant or a large single dose of electrons, has been reported to be safe and can permanently cure the bladder of cancer and also preserve bladder function in more than 75% of patients with solitary tumors that invade into but not beyond the bladder muscle. With the increasing interest in and availability of intraoperative radiation therapy in the US, this curative and bladder-sparing treatment for operable patients with bladder cancer invading the trigone is appropriate for careful clinical trial.

Prognostic indices for bladder cancer: an analysis of patients with transitional cell carcinoma of the bladder primarily treated by radical megavoltage X-ray therapy

A group of 889 patients who completed radical X-ray therapy for transitional cell carcinoma of the bladder during a 12 year period were analysed by a multivariate technique. The patient's age, tumour category, tumour size and haemoglobin level were shown to be independent prognostic covariates. A prognostic index was derived and four prognostic subgroups were identified. The prognostic index could divide patients within each T category into those with good, moderate, fair or poor prognosis. The 5 year actuarial survival rate for patients in the poor prognosis group was 5.8% compared to 69.8% for patients in the good prognosis group. Durable local tumour control after radical radiotherapy was also analysed by a multivariate technique. Tumour category, grade, haemoglobin and urea level were found to be significant covariates. A tumour control index was derived and two groups were identified corresponding to a high probability of lasting local control after radical radiotherapy (47.8% of patients) or a low probability of control (52.2%).

Factors influencing the prognosis in bladder cancer

In the categories T1, T2 and T3NxM0 bladder cancer, diameter not exceeding 5 cm, the treatment in the Rotterdam Radio-Therapy Institute consists of interstitial irradiation with needles containing radioactive material. The results of treatment and the role of additional external irradiation are discussed. Category T3NxM0 tumors diameter exceeding 5 cm are treated by external irradiation followed by cystectomy; the results are presented here. Factors influencing prognosis appeared to be degree of differentiation, number of transurethral resections (TURs) prior to definitive treatment, intravenous pyelography (IVP), vascular invasion, T category after preoperative irradiation, and postsurgical histopathologically-assessed T category (pT).

Results of implantation for T1 and T2 bladder tumours

In the period from January 1972 through December 1983 a total of 123 patients was treated for a bladder malignancy by preoperative external irradiation followed by interstitial therapy. Criteria for selection of patients are solitary lesion, tumour smaller than 5 cm in diameter, state T1 and T2. The majority of patients was in state T2 (89 patients). Persisting local control was achieved in 29 out of 34 T1 cases and in 69 out of 85 T2 cases. The actuarial 10 years survival was 72% for T1 and 34% for T2, with a total disease-free percentage at 10 years of 77% for T1 and 56% for T2. Although in many patients delayed wound healing was noticed, no serious late reactions were seen in skin, bladder or intestine. The causes of death are distant metastases in 13 patients and intercurrent diseases in another 21 patients.

Radical irradiation of T2 and T3 bladder carcinoma. A retrospective investigation

The relative 5-year survival was 32 per cent in 97 patients with T2 or T3 bladder carcinoma (1972-1978) treated with high dose radiation therapy (CRE greater than or equal to 1700 reu). A slight but significant difference was noted between the two T categories. Fifty-three patients who were tumour-free 3 to 4 months after irradiation had a 55 per cent survival. No other prognostic parameters were identified on the basis of histologic or radiologic findings. In 14 patients severe radiation complications were observed (bladder 9, small bowel 3, combined 2). In patients with radiation sensitive bladder carcinoma, radical radiation therapy seems to be a comparable alternative to total cystectomy.

Treatment of bladder tumors by iridium 192 implantation. The Créteil technique

The technique and results of a treatment protocol for bladder cancer combining low dose pre-operative external beam irradiation followed by external iliac nodal dissection, limited partial cystectomy and curietherapy with iridium 192 are described. In 55 patients treated from 1971 to 1979, 37/45 (67%) are alive NED at 5 years--23/31 pT1, 10/14 pT2, 4/10 pT3--with 9/55 bladder recurrences at 5 years--7/31 pT1, 1/14 pT2, 1/10 pT3. Only two patients (total cystectomy) have not retained a functional bladder. These favorable results have been obtained in a carefully selected population; our indications for the technique being T1, T2, T3a tumors with a total surface area not exceeding 5 cm, not involving the bladder neck and unifocal or in some cases plurifocal, but closely grouped. The advantages and precise details of each stage of the technique will be described and compared with large series in which radium 226 is utilized and results of curietherapy will be compared with other modalities of treatment employed under similar circumstances for similar patient groups. We feel that curietherapy has certain advantages over other methods in the treatment of bladder cancer and that an afterloading technique employing iridium 192 wires permits the curietherapy to proceed under optimal conditions, allowing combination with partial cystectomy, optimal placement of sources, precise radiographic control and dosimetry, dose reduction in many cases, optimal conditions of radioprotection and widening of the indications for the technique.

Full-dose irradiation for patients with invasive bladder carcinoma: clinical and histological factors prognostic of improved survival

We reviewed the outcome of 55 patients treated from 1974 to 1982 by full-dose radiation therapy (6,400 to 6,800 rad) to identify factors associated with tumor radioresponsiveness and patient cure. All patients had histological proof of muscle invasion by tumor. Of the patients 8 (14 per cent) had clinical stage T2, 29 (53 per cent) stage T3 and 18 (33 per cent) stage T4 disease. Thirteen patients are alive, all but 2 without evidence of cancer. Survivors include 1 of 9 patients who underwent salvage cystectomy for a local recurrence. The actuarial 5-year survival rate for the entire group was 28 per cent, with a corrected survival of 33 per cent. Median survival was 2.3 years. Corrected survival for patients with stages T2 and T3 disease was 45 per cent versus 9 per cent for those with stage T4 cancer (p equals 0.009). Within the group with stages T2 and T3 cancer (all with proof of muscle invasion) the most striking prognostic factor was papillary surface histological findings, with local control by radiation therapy alone of 63 per cent versus 20 per cent in the group with solid or flat tumors (p equals 0.01), and corrected 5-year survival of 62 per cent (papillary) versus 0 per cent (flat or solid) (p equals 0.002). Other significant prognostic factors for 5-year survival in this group were extent of transurethral resection (54 per cent complete versus 17 per cent incomplete, p equals 0.009) and ureteral obstruction on excretory urography (47 per cent without versus 14 per cent with, p equals 0.01). Our results suggest that full-dose radiation therapy can be offered to patients with muscle-invading bladder cancer, with a relatively higher probability of success in those with less advanced tumors by clinical stage, papillary surface histological findings and no ureteral obstruction, and in whom a complete transurethral resection is possible.

Bladder cancer. The selection of patients for treatment by full-dose irradiation

Cure of muscle-invading bladder carcinoma in 20% to 39% of patients using full-dose external beam irradiation has been reported by many institutions in the last 10 years. Local failure occurs in 50% of patients so treated, however, and successful selection criteria for bladder-sparing radiotherapy are necessary. Prognostic factors which have been identified to be associated with a relatively successful outcome using full-dose irradiation include (1) the clinical stages T2 and T3, (2) the absence of ureteral obstruction on initial intravenous pyelogram, (3) a visibly "complete" transurethral resection having been achieved, and (4) complete response of the local tumor to radiation. In addition, local tumor control appears to be related to total dose administered. Analysis of the results of precystectomy radiation therapy, where papillary tumor histology and small tumor size yielded improved survival, suggests that these characteristics also may prove to be beneficial in patients selected for full-dose irradiation. The four-field box technique has become accepted as the best method to treat patients using beams from linear accelerators or betatrons. The bladder and pelvic lymph nodes should be treated to 50.4 Gy in 1.8 Gy fractions, 5 days/week. A cone-down boost to the tumor volume only then is given for a total dose of 64.8 Gy to 68.4 Gy in 7.5 weeks. The posterior rectosigmoid should receive less than 60 Gy, and the anus and femoral head and neck should be limited to 45 to 50 Gy to avoid toxicity. Innovative approaches to treatment of muscle-invading bladder cancer now are being explored and include the use of intravesical misonidazole combined with fractionated external beam irradiation, and systemic cisplatin administration in combination with radiation. Techniques which have yielded good results in superficial bladder cancer include open interstitial implantation, intraoperative single-dose electron beam irradiation, and trans-Foley radium applications. Further prospective evaluations of clinical and histologic tumor characteristics, treatment techniques and doses reviewed here will be necessary before definitive selection criteria for treatment with full-dose irradiation are established.

Relation between local cure and dose-time-volume factors in interstitial implants

The dose and volume data of 119 patients treated with radium or iridium-192 implants for cancer of the tongue, bladder or perineum are presented. The computer dosimetry system used in the Antoni van Leeuwenhoek Hospital permitted analysis of data regarding treated volume, dose variation inside the treated volume, patterns of geographical defects and their impact on the result of treatment. Dose was expressed in a number of ways, including prescribed (reference) and average dose and the CRE (Cumulative Radiation Effect) level attained. The CRE value included a time correction and a volume correction. The average dose proved to be the best predictor of local result in case of tongue and perineal implants. Great care is needed in case of tongue carcinoma to avoid a geographical miss by an inadequate treatment volume or geometric defects. The hypothesis that a dose reduction factor is necessary, in case of a high dose rate, could not be validated.