High dose rate brachytherapy for superficial cancer of the esophagus

Dose reduction in HDR brachytherapy of esophageal cancer using gold and gold alloy plaques: a Monte Carlo study

In this work, the use of gold and gold alloy plaques is proposed for the first time, to reduce the dose to healthy organs in brachytherapy with Ir-192 sources. For dose simulations in tumour and healthy tissue, the MCNPX Monte Carlo code was used. The radiation source implemented in those simulations was benchmarked with well-known TG-43 criteria of dose rate constant, air-kerma strength, radial dose function, and 2D anisotropy function. For various arrangements of iridium sources and plaques of gold and gold alloy of various thicknesses, the dose distributions in an esophagus tumour and in surrounding healthy organs were simulated. The results showed that while the dose to the tumour is not much affected by the presence of gold plaques with a thickness of 3.5 mm in an optimized ¹⁹²Ir sources' configuration, a relative reduction in average organ dose of 64%, 65%, 73%, 67%, and 35% was observed, for esophagus, thyroid, heart, stomach, and liver, respectively. Moreover, it was found that a gold plaque leads to smaller doses to healthy organs than a gold alloy plaque. It is concluded that gold plaques can be used to improve the treatment of esophageal cancer by HDR brachytherapy and to protect surrounding non-target organs.

Multidisciplinary Evaluation and Management of Early Stage Esophageal Cancer

Early esophageal cancer involves the mucosal and submucosal layers of the esophagus. Early esophageal cancer is a heterogeneous group, and achieving optimal outcomes requires a multidisciplinary approach to align patients to their optimal treatment. Although organ-sparing endoscopic resection has become the preferred management option for superficial esophageal cancer, it is not adequate in all tumors, such as high-risk lesions with poorly differentiated pathology, lymphovascular invasion, or deep submucosal invasion. In such high-risk lesions, surgery, chemotherapy, and/or radiation may be required. In this article, we present our multidisciplinary approach to early esophageal cancer.

Esophageal brachytherapy: Institut Gustave Roussy's experience

PURPOSE

Esophageal cancer is characterized by its propension to local evolution, which conditions prognosis and quality of life. Brachytherapy may be a therapeutic option for all stages of esophageal cancer.

METHODS AND MATERIALS

This retrospective unicentric study included all consecutive patients treated for an esophageal high-dose-rate brachytherapy in our institution from 1992 to 2018.

RESULTS

Ninety patients were included. They were treated in four distinct indications: exclusive (7 patients), boost after external beam radiotherapy (41), reirradiation (36), or palliative aim (6). Most frequently prescribed schemes were 3 × 5 Gy (boost) or 6 × 5 Gy (exclusive treatment and reirradiation) at applicator's surface or at 5 mm. At the end of follow-up, 50% of patients had presented with local recurrence. Seventeen percent of patients had a metastatic relapse. Median overall survival was 15 months in the whole cohort: 22 months in the boost setting, 25 months for exclusive brachytherapy, 15 months for reirradiation, and only 2 months for palliative treatment. Tumor length at brachytherapy, brachytherapy dose, and interfraction response were significantly associated to overall survival. 40% of patients presented with grade 2+ toxicity, mostly esophagitis, including three toxic deaths.

CONCLUSIONS

Although local control outcomes are still poor, one must remember that patients are unfit for any curative therapeutic option and that palliative chemotherapy offers mediocre results. The most promising setting probably is reirradiation because brachytherapy offers a remarkable dose gradient allowing best organ at risk sparing, with an encouraging rate of long survivors (19% at 2 years). Esophageal brachytherapy deserves to be further investigated because some patients, even unfit, may benefit from it, with acceptable toxicity.

Esophagus and Gastrointestinal Junction Tumors

Esophageal squamous cell carcinoma and adenocarcinoma account for 95% of all esophageal malignancies. The rates of esophageal adenocarcinoma have increased in Western countries, making it the predominant type of esophageal cancer. Treatment of both types of cancer has transformed to a more minimally invasive approach, with endoscopic methods being used for superficial cancers and more frequent use of video-assisted and laparoscopic modalities for locally advanced tumors. The current National Comprehensive Cancer Network guidelines advocate a trimodal approach to treatment, with neoadjuvant chemoradiation and surgery for locally advanced cancers.

Endoluminal brachytherapy: Bronchus and oesophagus

Endobronchial brachytherapy could be proposed in case of endoluminal tumours either as a palliative or a curative treatment. As a curative treatment, endobronchial brachytherapy could obtain a high local control rate in case of limited disease. In palliative setting, endobronchial brachytherapy improved thoracic symptoms in more than 80% of cases, but it is less efficient than external beam radiation therapy for palliation. It could be also proposed to maintain the airway open after laser therapy. Oesophageal brachytherapy is a valuable option as a palliative treatment, underused at this time. It causes less side effects and a better quality of life compared to self-expanded metallic stents. For a curative aim, there is today no demonstration that a combination of external beam radiotherapy and oesophageal brachytherapy give better results than external beam radiotherapy alone in locally advanced tumours. For superficial diseases, the combination of external beam radiotherapy and oesophageal brachytherapy seems, on the contrary, promising.

Salvage high-dose-rate brachytherapy for esophageal cancer in previously irradiated patients: A retrospective analysis

PURPOSE

To evaluate outcomes after exclusive salvage high-dose-rate (HDR) intraluminal esophageal brachytherapy given to previously irradiated patients with recurrent esophageal cancer.

METHODS AND MATERIALS

We reviewed medical records of 30 patients who were treated by salvage HDR brachytherapy for local esophageal cancer. Brachytherapy delivered four to six fractions of 5-7 Gy at 5 mm from the applicator surface and 20 mm above and below the macroscopic tumor volume.

RESULTS

Eighty percentage of patients received treatment as initially planned. Complete response rate, evaluated 1 month after brachytherapy by endoscopy and biopsy, was 53%. Squamous histology and complete endoscopic tumor response at 1 month were significantly associated with better local tumor control. Median local progression-free survival was 9.8 months. Overall survival was 31.5% and 17.5% at 1 and 2 years, respectively. On univariate analysis, preserved performance status and limited weight loss (<10%) before salvage brachytherapy were associated with better overall survival. Severe toxicity (Grade ≥3) occurred in 7 patients (23%).

CONCLUSIONS

Although esophageal cancer in previously irradiated patients is associated with poor outcomes, HDR brachytherapy may be a valuable salvage treatment for inoperable patients with locally limited esophageal cancer, particularly in the subset of patients with preserved performance status and limited weight loss (≤10%) before salvage brachytherapy.

[Brachytherapy for oesophageal cancer]

The main indication of oesophageal brachytherapy is palliative: it can improve dysphagia in patients with a tumor not suitable for surgery or chemoradiotherapy. A randomized clinical trial showed that survival without dysphagia and quality of life was improved by endoluminal brachytherapy in comparison to self-expansible metallic stents. It also increases the duration of palliation after laser deobstruction. Its role as a curative treatment of locally advanced tumors is still discussed: in combination with external beam radiotherapy, it seems that brachytherapy increased the rate of severe toxicity (haemorrhages, fistula, stenosis). In superficial lesions, brachytherapy with or without external beam radiotherapy seems logical but large prospective studies are missing in this setting.

Comparison of efficacy and safety of low-dose-rate vs. high-dose-rate intraluminal brachytherapy boost in patients with superficial esophageal cancer

PURPOSE

To compare the efficacy and the incidence of complications of high-dose-rate (HDR) and low-dose-rate (LDR) intraluminal brachytherapy (IBT) boost after external beam radiation therapy in patients with superficial esophageal cancer.

METHODS AND MATERIALS

Fifty-four consecutive patients with Stage I thoracic esophageal squamous cell carcinoma who were treated with definitive radiotherapy using IBT between 1991 and 2007 were studied retrospectively. LDR-IBT and HDR-IBT were performed for 19 and 35 patients, respectively. After external beam radiation therapy of 56-60 Gy with a conventional fractionation, LDR-IBT (5 Gy × 2) or HDR-IBT (3 Gy × 3) was given within 2 weeks. The median follow-up was 47 months (7-151 months).

RESULTS

Overall, the 5-year overall survival, cause-specific survival (CSS), and locoregional control (LRC) rates were 61%, 86%, and 79%, respectively. The 5-year overall survival, CCS, and LRC rates did not differ significantly between the LDR-IBT and HDR-IBT groups (68% vs. 58% (p=0.50), 83% vs. 85% (p=0.63), and 84% vs. 75% (p=0.42), respectively). Salvage treatment was given in 8 locally recurrent patients, and 6 patients were rescued. The Grade ≥2 late morbidities of esophagus and heart/lung were observed in 5 patients (4 in the LDR-IBT group and 1 in the HDR-IBT group) and 2 patients (one from each group), respectively.

CONCLUSIONS

In view of the safety profile and effectiveness, our results encourage the continued adoption of HDR-IBT as radiation boost in medically inoperable or elderly superficial esophageal cancer patients undergoing definitive radiotherapy.

The multidisciplinary management of gastrointestinal cancer. Multimodal treatment of oesophageal cancer

Treatment of oesophageal cancer requires a multidisciplinary approach. Single modality treatment, especially surgical excision, is only indicated in small tumours or in patients unable to support multimodal treatment. In Stage I-II adenocarcinoma, multimodal treatment using neoadjuvant therapy is indicated in the absence of contra-indications. However, this statement is not universally accepted. The choice between radio-chemotherapy and chemotherapy depends on patients' characteristics and the preferences of the treatment centre. In selected Stage III adenocarcinomas, especially from the lower oesophagus, neoadjuvant chemotherapy (with post-operative chemotherapy when feasible) may induce tumour regression, which may facilitate surgical resection and improve survival rates, as has been demonstrated for cancers of the oesophagogastric junction.

High dose rate brachytherapy (HDR-BT) in locally advanced oesophageal cancer. Clinic response and survival related to biological equivalent dose (BED)

INTRODUCTION

Ninety percent of oesophageal cancers are locally advanced at diagnosis, and treatment yields discouraging results. High dose rate brachytherapy (HDR-BT) permits an increment of local doses without a significant increment of toxicity. The goal of our study is to compare different HDR-BT fractions and assess global survival (GS) and cause-specific survival (CSS).

MATERIAL AND METHODS

Twenty-six patients were treated for locally advanced oesophageal cancer with chemotherapy concomitant with conformal three-dimensional radiotherapy (C3DR) from January 1994 to December 2000. Of this group, 96.2% were males, mean age 63.08 years; the most frequent location was medium third, for 50% of cases. Eighty-four percent of cases were G2-3 epidermoid carcinomas. The administration consisted of 44.2 Gy with C3DR and 5 applications of HDR-BT of 500 cGy each.

RESULTS

Actuarial GS and CSS at 5 years is 10.18% and 12.96%, a mean survival of 25.68 and 29.14 months respectively. The following factors (C3DR total dose, fraction dose and total dose of HDR-BT, number of applications, active length of application, total dose of C3DR plus HDR-BT, and BED of HDR-BT) are evaluated to find if they have an influence on treatment response, GS and actuarial CSS. The only result that yields statistical significance, in univariant analysis, is the active length in HDR-BT, thus for a greater active length of application, a minor response is obtained and GS diminishes (p=0.05). We grouped BT fractions on biological equivalent dose (BED) into: <28, 28-33 and >33 Gy; mean survival and GS at 5 years increases with BED>or=28 Gy (p=0.016).

CONCLUSION

Tumour response increases (complete and partial) when BED on HDR-BT is increased, regardless of the fraction employed. A BED higher than 28 Gy yields a significant increase of mean survival and GS at 5 years (p=0.016).

External beam radiation therapy followed by high-dose-rate brachytherapy for inoperable superficial esophageal carcinoma

PURPOSE

The aim of this study was to retrospectively evaluate the feasibility, efficacy, and tolerance of external beam radiotherapy followed by high-dose-rate brachytherapy in inoperable patients with superficial esophageal cancer.

PATIENTS AND METHODS

From November 1992 to May 1999, 66 patients with superficial esophageal cancer were treated with exclusive radiotherapy. The median age was 60 years (range, 41-85). Fifty-three percent of them were ineligible for surgery owing to synchronous or previously treated head-and-neck cancer. Most of the patients (n = 49) were evaluated with endoscopic ultrasonography (EUS) or computed tomography (CT). The mean doses of external beam radiotherapy and high-dose rate brachytherapy were 57.1 Gy (+/-4.83) and 8.82 Gy (+/-3.98), respectively. The most frequently used regimen was 60 Gy followed by 7 Gy at 5 mm depth in two applications.

RESULTS

Among patients evaluated with EUS or CT, the complete response rate was 98%. The 3-, 5-, and 7-year survival rates were 57.9%, 35.6%, and 26.6%, respectively. Median overall survival was 3.8 years. The 5-year relapse-free survival and cause-specific survival were 54.6% and 76.9%. The 5-year overall, relapse-free, and cause-specific survival of the whole population of 66 patients was 33%, 53%, and 77%, respectively. Local failure occurred in 15 of 66 patients; 6 were treated with brachytherapy. Severe late toxicity (mostly esophageal stenosis) rated according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale occurred in 6 of 66 patients (9%).

CONCLUSION

This well tolerated regimen may be a therapeutic alternative for inoperable patients with superficial esophageal cancer. Only a randomized study could be able to check the potential benefit of brachytherapy after external beam radiation in superficial esophageal cancer.

Radiation therapy alone for stage I (UICC T1N0M0) squamous cell carcinoma of the esophagus: indications for surgery or combined chemoradiotherapy

BACKGROUND AND AIM

The aim of this study was to clarify the efficacy and limitations of radiation therapy (RT) for superficial esophageal carcinoma, and to explore the indications for more aggressive therapy, such as combined chemo-radiotherapy.

METHODS

Sixty-eight patients with stage I (UICC T1N0M0) esophageal squamous cell carcinoma treated by definitive RT alone were analyzed. Brachytherapy was administered in 36 patients as a boost, and the prescribed doses were 10 Gy (5 Gy x 2 times) at a low dose rate (19 patients) and 9 Gy (3 Gy x 3 times) at a high dose rate (17 patients). Recurrence patterns and survival rates were assessed and the factors predisposing to recurrences after RT were statistically investigated by univariate analysis.

RESULTS

The 5-year cause-specific survival rate and the locoregional control rate were 79.9% and 82.1%, respectively. No case of recurrence or disease-related death was observed in any of the patients with mucosal cancer. Among the cases with the cancer invading the submucosa, there were 12 cases with locoregional recurrence and two cases with distant metastases. In cases of submucosal esophageal cancer, the tumor length was the only statistically significant factor predicting locoregional control. The 5-year locoregional control rate in cases with a short length of the tumor (<or=5 cm) was 83.3%, whereas the corresponding rate in cases with the tumor measuring >5 cm in length was 57.8% (P = 0.036). Patients treated by additional brachytherapy exhibited better cause-specific survival and locoregional control rates than those receiving external RT alone, however, the addition had no statistically significant influence on the outcome.

CONCLUSIONS

RT was a successful treatment for stage I esophageal cancer, and the treatment outcome using RT was nearly comparable to that of surgery. However, it is suggested that chemo-radiation should be considered in inoperable cases of submucosal cancer when the tumor is more than 5 cm in length.

The Experience of Concurrent Chemoradiation for Japanese Patients With Superficial Esophageal Squamous Cell Carcinoma: A Retrospective Study

PURPOSE

To evaluate the treatment outcome of concurrent chemoradiation therapy (cCRT) for 13 clinically confirmed T1 esophageal cancer patients.

METHODS

Between June 2000 and February 2004, patients with T1 esophageal cancer (tumor invading lamina propria or submucosa) received cCRT (50.4 Gy; CDDP: 75 mg/m2, day 1, bolus; 5-FU: 1000 mg/m2, days 1 to 4, continuous) (n = 13, T1 group). This treatment regimen was compared with the following 2 other groups treated during the same period: one was treated with radiation therapy alone for T1 disease (n = 5, RT-alone group); and the other group of patients consisted of those with T2 disease (tumor invading muscularis propria) who received the same cCRT regimen as the first T1 group (n = 9, T2 group).

RESULTS

The overall survival rates at 1 and 3 years were in the T1 group, 75% and 75%; in the T2 group, 75% and 45% (P =0.2890); and in the RT-alone group, 60% and 40% (P = 0.2978). No treatment-related mortalities occurred in the T1 and RT-alone groups, but one patient in the T2 group died of radiation-induced pneumonitis.

CONCLUSIONS

Although this study was not randomized, the results showed that cCRT is a safe and effective method for treating patients with superficial esophageal cancer.

Long-term results of definitive radiotherapy for stage I esophageal cancer

PURPOSE

To analyze retrospectively the long-term results of external beam radiotherapy (RT) with or without intraluminal brachytherapy (ILBT) for patients with Stage I esophageal cancer.

METHODS AND MATERIALS

A total of 34 patients with esophageal squamous cell carcinoma, clinically diagnosed as having Stage I disease, were treated with definitive RT, with or without ILBT. The median age was 69 years. Seven patients were treated with external beam RT alone (median, 64 Gy), and 27 were treated with external beam RT (median, 52 Gy) plus ILBT (8-12 Gy in two to three fractions).

RESULTS

The 5-year overall survival, local relapse-free survival, and cause-specific survival rate was 58.9%, 68.4%, and 80.0%, respectively, with a median follow-up of 61 months. Of 9 patients with local recurrence after initial therapy, 7 were successfully treated, and the 5-year cumulative rate of esophagectomy was 19.6%. The 2-year local relapse-free rate for patients with and without ILBT was 79.1% and 53.6%, respectively.

CONCLUSION

Although local recurrence was frequent within 2 years, the disease-specific survival rate was high owing to effective salvage therapy. Definitive RT is a reasonable treatment option for highly comorbid and elderly patients with Stage I esophageal cancer. The role of ILBT needs to be clarified.

Clinical results of radiation therapy for stage I esophageal cancer: a single institutional experience

From 1992 through 2001, 29 patients with stage I esophageal cancer were treated with radiation therapy. All patients had squamous cell carcinoma. Seventeen patients were treated with radiotherapy alone, and 12 were treated with a combination of chemotherapy and radiotherapy. Most of the chemotherapy regimens included cisplatin and/or 5-fluorouracil (5-FU). Twelve patients were treated with intracavitary irradiation (low-dose rate: 6, high-dose rate: 6) after external radiotherapy. Median fraction and total doses of external radiotherapy given were 2.0 Gy and 60.6 Gy, respectively. Median doses of intracavitary irradiation were 18 Gy/6 fractions in low-dose-rate brachytherapy and 13.5 Gy/4.5 fractions in high-dose-rate brachytherapy. The 5-year overall survival rate was 62%. The 5-year local control rate was 44%. Of the 29 patients, 9 had in-field recurrence in the esophagus and 1 had recurrence in the esophagus outside of the irradiated field. Of 9 patients with in-field local recurrence, 1 also developed mediastinal lymph node metastases and 1 had distant metastasis. Radiation therapy is an effective treatment modality for stage I esophageal cancer.

Photodynamic therapy for early oesophageal cancer

BACKGROUND

Photodynamic therapy is an endoscopic treatment of early cancers based on the photosensitisation of neoplasms following the administration of a photosensitiser prior to laser light-induced tissue destruction.

AIM

To assess the results of photodynamic therapy using Photofrin(Axcan Pharma Inc., Quebec, Canada) in patients with an early oesophageal cancer.

PATIENTS

Twenty-four patients with early oesophageal cancer presenting as a not well-demarcated irregular dyschromic area of mucosa and unsuitable for any other treatment underwent photodynamic therapy. RESULTS.: Seventy-five per cent were successfully treated; three of them recurred and two died from head and neck cancer. To date, 54% of patients are alive without recurrence; the average follow-up is 21 months. There were one oesophageal lethal perforation and six stenosis. Results of photodynamic therapy were limited in this series by three failures, three recurrences and three deaths from previous head and neck cancers.

CONCLUSION

This study provides some promising data for photodynamic therapy of oesophageal carcinomas in selected patients. It also emphasises the need for a best delivery device of laser light.

Clinical outcomes and prognostic factors for patients with early esophageal squamous cell carcinoma treated with definitive radiation therapy alone

GOALS AND BACKGROUND

There are great differences between treatment methods for early-stage esophageal cancer in institutions. Radiation therapy has been considered to be an effective modality as organ-preserving treatment of the disease. The aim of this study is to assess the effect and limitation of radiation therapy on patients with early esophageal cancer.

STUDY

The subjects were 38 patients with stage I (T1N0M0) squamous cell carcinoma of the esophagus who had received definitive radiation therapy alone. Eleven tumors were assessed within the mucosal layer, whereas 27 tumors showed submucosal invasion by examination using endoscopic ultrasound. All patients were treated with more than 60 Gy using a conventional daily fractionation dose at 2 Gy. An additional boost with brachytherapy was performed for 20 patients, and the prescribed doses were 10 Gy (5 Gy x 2 times) with low dose rate (8 patients) and 9 Gy (3 Gy x 3 times) with high dose rate (12 patients). Outcomes and prognostic factors, including the efficacy of intraluminal brachytherapy, were investigated.

RESULTS

The cause-specific survival rate and the local control rate at 5 years were 82.6% and 86.3%, respectively. Recurrences were noted in 8 patients with submucosal cancer, but no recurrence was observed in patients with mucosal cancer. In the present study, tumor length was a statistically significant prognostic factor for cause-specific survival (P = 0.018) and tumor depth tended toward statistical significance (P = 0.073). In 27 patients with submucosal cancer, the tumor length was also statistically significant for the survival (P = 0.032). The 5-year cause-specific survival rates for the short tumor group and the long tumor group were 85.7% and 55.6%, respectively. On the other hand, the use of intraluminal brachytherapy had no significant effect on patient survival.

CONCLUSION

Radiation therapy is very effective for early esophageal squamous cell carcinoma with tumor length less than 5 cm, but other treatment modalities, including chemoradiotherapy especially for inoperable patients, should be considered for submucosal cancer with a tumor length of 5 cm or more.

Palliative treatment by high–dose-rate intraluminal brachytherapy in patients with advanced esophageal cancer

PURPOSE

The aim of this work was to analyze the results of palliative HDR brachytherapy in patients with advanced esophageal cancer.

METHODS AND MATERIALS

Ninety-one patients with unresectable, advanced esophageal cancer were treated palliatively by HDR brachytherapy. All patients received a total dose of 22.5 Gy in three fractions per week. Remissions of dysphagia and other clinical and radiological factors were assessed in the first month posttreatment, and then in the third, sixth, and twelfth months. The survival rate was compared with some chosen clinical factors using a log-rank test and the Kaplan-Meier method.

RESULTS

The median survival time among all patients was 8.2 months. The median survival time according to the obtained remission was 14.6, 7.2, and 3.8 months (log-rank p = 00001, F Cox p = 0.00001) for complete remission (CR), partial remission (PR), and lack of remission (NR), respectively. A longer median survival time was observed when tumor size was less then 5 cm (12.1 months), than between 5 and 10 cm (7.8 months), or longer than 10 cm (6.4 months) (log-rank p = 0.002). Longer median survival times were observed in clinical stage II (14.1 months), compared with clinical stage III (7.7 months) and IV (7.2 months) (log-rank p = 0.01). Significant correlations were found between survival and the Karnofsky Performance Status, grade of dysphagia, and age.

CONCLUSIONS

HDR brachytherapy for advanced esophageal cancer allowed for improvement of dysphagia in most patients. The complete or partial remission, the older age of patients, and the lower grade of dysphagia observed in first month posttreatment were the most important prognostic factors allowing for prolonged survival (confirmed by a multivariate analysis). In the univariate analysis, important prognostic factors for prolonged survival were: a higher Karnofsky Performance Status, a lower clinical stage and a small tumor size.

New approach to malignant strictures of the esophagus

Primary esophageal cancer is the most common cause of malignant esophageal stricture. Prognosis and treatment outcomes vary with the stage of the disease. Endoscopic ultrasound has a high accuracy rate for local and regional staging. Surgery is curative for early cancer. Endoscopic mucosal resection, photodynamic therapy, or brachytherapy can be used with curative intent for early cancer, especially in patients with comorbid conditions precluding surgery. Unfortunately, the majority of patients with esophageal cancer present with advanced disease. The primary aim in these patients is to alleviate symptoms with a minimum of side effects and reinterventions. Palliative surgery or chemoradiotherapy can be associated with high morbidity and mortality rates. Several endoscopic techniques for palliation are available, and all have the potential of significantly improving swallowing. The choice of a particular endoscopic approach is usually determined by local expertise and characteristics of the stricture.

Self-expandable covered metallic esophageal stent impregnated with beta-emitting radionuclide: an experimental study in canine esophagus

PURPOSE

A specially designed self-expandable covered metallic stent impregnated with the beta-emitting radioisotope 166Ho (166Ho, energy: 1.85 and 1.76 MeV, T12: 26.8 h) was developed at our institute for the purpose of intraluminal palliative brachytherapy, as well as for treating malignant esophageal stricture and swallowing difficulty. The aim of this study was to evaluate the tissue response to brachytherapy and the safety of the radioactive metallic stent with regard to the normal canine esophagus before clinical application.

METHODS AND MATERIALS

166Ho was impregnated into the polyurethane membrane (50 micron thickness) covering the outer surface of a self-expandable metallic stent (diameter, 18 mm; length, 40 mm). Stents with radioactivity 4.0-7.8 mCi (Group A, n = 15), 1.0-1.8 mCi (Group B, n = 5), and 0.5-0.7 mCi (Group C, n = 5) were placed in the esophagi of 25 healthy beagle dogs, and the stents were tightly anchored surgically to prevent migration. The estimated radiation dose calculated by Monte Carlo simulation was 194-383 Gy in Group A, 48-90 Gy in Group B, and 23-32 Gy in Group C. The dogs were killed 8-12 weeks after insertion of the stents, and histologic examinations of the esophageal walls were performed.

RESULTS

In Group A, 3 of 15 dogs died of wound infection, so specimens were obtained from only 12 dogs; all 12 cases showed esophageal stricture with mucosal ulceration. Microscopically, severe fibrosis and degeneration of the muscular propria were found in 3 dogs, complete fibrosis of the entire esophageal wall was found in 7 dogs, and esophageal fibrosis with radiation damage within periesophageal soft tissue was found in 2 dogs. However, esophageal perforation did not develop, despite extremely high radiation doses. In Group B, glandular atrophy and submucosal fibrosis were found, but the muscular layer was intact. In Group C, no histologic change was found in 3 dogs, but submucosal inflammation and glandular atrophy with intact mucosa were found in 2 dogs.

CONCLUSIONS

A radioactive, self-expandable covered metallic stent can be used as an alternative therapeutic modality for the palliative treatment of malignant esophageal stricture.

Therapeutic effects of simultaneous intraluminal irradiation and intraluminal hyperthermia on oesophageal carcinoma

An applicator enabling simultaneous intraluminal radiotherapy and intraluminal hyperthermia delivery was developed to improve the treatment results for locally advanced oesophageal carcinoma. Eight inoperable cases were treated by this method. Six cases received 40 Gy external irradiation followed by simultaneous intraluminal hyperthermia and radiotherapy (3 Gy and 4 Gy in three cases each) once weekly for 3 weeks; the remaining two cases received 50 Gy external irradiation followed by simultaneous intraluminal hyperthermia and radiotherapy (4 Gy) once weekly for 2 weeks. Hyperthermia was delivered by a radiofrequency current thermotherapy instrument for 30 min at an output that raised the oesophageal mucosal surface temperature to 42-43 degrees C. Intraluminal radiotherapy was delivered with a microSelectron to a submucosal depth of 5 mm after the first 15 min of hyperthermia. Four cases achieved complete response, with all demonstrating local control. Partial response was obtained in four cases, and three of these patients died of local recurrence. There were no significant adverse side effects apart from fistula in one case. In conclusion, simultaneous intraluminal radiotherapy and hyperthermia may improve the current treatment results for locally advanced oesophageal carcinoma.

Surgery, radiotherapy, and chemotherapy for esophageal carcinoma

Over the last year, several interesting studies have been published on the treatment of esophageal carcinoma. Surprisingly, none of them was a randomized phase III trial. The debate on the necessary extent of a potentially curative surgical resection is ongoing. After initially disappointing results, the innovative technique of minimally invasive surgery draws new attention, but clear advantages for the endoscopic approach are yet to emerge. An updated meta-analysis on the value of preoperative radiotherapy showed negative results. There is a clear tendency toward combined-modality treatment, especially in patients with more advanced disease. Some new chemotherapeutic agents showed promising preliminary results (especially paclitaxel), whereas others were clearly disappointing (eg, gemcitabine, topotecan). Concurrent chemoradiation as primary treatment for proximal (cervical) tumors was remarkably effective.

Radiation therapy for superficial esophageal cancer: a comparison of radiotherapy methods

PURPOSE

A comparison of treatment outcomes in response to various methods of radiotherapy for superficial esophageal cancer (SEC) was carried out for a large series of patients.

METHODS AND MATERIALS

During the period from March 1987 to November 1998, 147 patients with superficial esophageal cancer received definitive radiation therapy at nine radiotherapy institutions in Japan. Fifty-five patients were treated with external radiation therapy alone, 69 with high-dose-rate intracavitary radiation therapy with or without external radiation therapy, and 23 with low-dose-rate intracavitary radiation therapy and external radiation therapy.

RESULTS

The 5-year survival rates for mucosal and submucosal cancer patients were 62% and 42%, respectively. The 5-year cause-specific survival rates for mucosal and submucosal cancer patients were 81% and 64%, respectively (p = 0.013). There was no statistically significant difference in the survival rates for either mucosal or submucosal cancer patients between treatment groups. Metastasis was observed only in submucosal cancer patients. Esophageal ulcers developed only in patients who received intracavitary radiation therapy, and were especially common in patients treated with a fraction size of 5 Gy or more.

CONCLUSIONS

The use of intracavitary radiation therapy does not influence the survival or local control rate of SEC. Optimal radiotherapy methods for SEC should be determined by a randomized clinical trial.

Squamous cell cancer of the oesophagus

Squamous cell cancer is the most common neoplasm of the oesophagus worldwide, with an enormous variation in its global incidence. Several risk factors, such as achalasia, Plummer-Vinson syndrome, coeliac disease and nutritional factors, have been identified. The surveillance of patients, especially those with tylosis or caustic ingestion, has been recommended. Vital staining with iodine may improve the diagnosis of early cancer. The endoscopic management of early cancer and dysplasia by minimal invasive techniques such as photodynamic therapy or mucosal resection has become attractive for many of these patients with co-morbidity.