Consensus guidelines for high dose rate remote brachytherapy in cervical, endometrial, and endobronchial tumors. Clinical Research Committee, American Endocurietherapy Society

I-125 seeds brachytherapy combined with immunotherapy for MET amplification in non-small cell lung cancer from clinical application to related lncRNA mechanism explore: a case report

Advanced non-small cell lung cancer (NSCLC) with MET amplification primarily relies on MET inhibitors for treatment, but once resistance occurs, the available treatment options are limited and the prognosis is typically poor. A 57-year-old man with advanced NSCLC and C-MET amplification was initially treated with crizotinib but developed progressive disease. After the antirotinib treatment, he achieved a partial response for a year. Genetic testing showed high PD-L1 expression, and he was treated with pembrolizumab and chemotherapy for 3 months, with partial response. Maintenance therapy with pembrolizumab and local I-125 seeds brachytherapy (ISB) was given after the lung lesion progressed but other lesions remained stable. The therapy resulted in significant resolution of the right upper lung lesion. It demonstrates the effectiveness of ISB-ICI combination in treating MET amplification advanced NSCLC. Ongoing research and treatment innovation are important in managing advanced NSCLC with complex genetic aberrations. To explore the candidate mechanism of ISB therapy response, we download public genetic data and conduct different expression Lncrnas analysis and pathway analysis to discover radiotherapy related sensitive or resistance lncRNAs and pathways, we found that AL654754.1 is a key lncRNA with radiotherapy response, and it also include in classical p53 and Wnt signaling pathway. Overall, the clinical case reports, combined with the exploration of underlying mechanisms, provide positive guidance for the precise treatment of lung cancer.

Analysis of dose distribution between contemporary and standard planning in high-dose-rate endobronchial brachytherapy based on three-dimensional imaging

Purpose

The treatment planning (TP) in high-dose-rate (HDR) endobronchial brachytherapy (EB) can be based on various forms of imaging. In the case of lung cancer, one-dimensional or two-dimensional imaging is standard. The dose coverage of the target (planning target volume – PTV) and organs at risk (OAR) is unknown, because the doses are calculated on the basis of the dose points. In modern brachytherapy, TP can be based on three-dimensional (3D) images. A plan created in this way contains information about the dose distribution in the PTV and OAR. Treatment plans based on standard planning (SP) and contemporary planning (CP) may differ in dose distribution in the patient’s body. Those differences between SP and CP may have an effect on the dose distribution in PTV, OAR and follow-up.

Material and methods

The study involved a group of 31 patients prospectively treated with advanced, inoperable, non-small cell lung cancer. As many as 76 treatment fractions were analyzed. Firstly, the coverage of the PTV parameter in 2D and 3D for V₈₅, V₁₀₀ and V₁₁₅ was analyzed. Secondly, the dosage that OAR would take in was evaluated. In the cases of the heart, spinal cord and esophagus, the examined dosage equaled D_0.1cm³, D_1cm³ and D_2cm³ for each of the structures. Also, heart D₂₀ was examined as well as D₅ for the healthy lung.

Results

The median dose to the target volume was on average 43.33% higher for V₈₅ with the contemporary planning method when compared to standard planning, with statistical significance. This came with the cost of an OAR mean dose increase of 1 Gy in D_0.1cm³ for the heart.

Conclusions

Contemporary TP in EB allows one to adjust the dose distribution for individual clinical situations and allows one to improve clinical target volume (CTV) coverage, increase doses to the OAR and increase overall survival. The use of new methods of treatment plans in EB has significantly increased the follow-up to 21 months in a treated group of patients.

American Brachytherapy Society consensus guidelines for thoracic brachytherapy for lung cancer

PURPOSE

To update brachytherapy recommendations for pretreatment evaluation, treatment, and dosimetric issues for thoracic brachytherapy for lung cancer.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in thoracic brachytherapy updated recommendations for thoracic brachytherapy based on literature review and clinical experience.

RESULTS

The American Brachytherapy Society consensus guidelines recommend the use of endobronchial brachytherapy for disease palliation in patients with central obstructing lesions, particularly in patients who have previously received external beam radiotherapy. The use of interstitial implants after incomplete resection may improve outcomes and provide enhanced palliation. Early reports support the use of CT-guided intratumoral volume implants within clinical studies. The use of brachytherapy routinely after sublobar resection is not generally recommended, unless within the confines of a clinical trial or a registry.

CONCLUSIONS

American Brachytherapy Society recommendations for thoracic brachytherapy are provided. Practitioners are encouraged to follow these guidelines and to develop further clinical trials to examine this treatment modality to increase the evidence base for its use.

Braquiterapia endobrônquica de alta taxa de dose: estudo dosimétrico

OBJETIVO: Avaliar a distribuição de dose em diferentes situações de braquiterapia endobrônquica de alta taxa de dose, com foco principalmente nos volumes de altas doses, e tentar definir situações de melhor ou pior distribuição de dose que possam servir de guia na prática clínica. MATERIAIS E MÉTODOS: Estudo teórico, simulando braquiterapia endobrônquica de alta taxa de dose utilizando dois cateteres, com variação da extensão de carregamento, angulação entre os cateteres, profundidade de cálculo e o intervalo entre as paradas da fonte. Com prescrição de 7,5 Gy, foram calculados os volumes englobados pelas isodoses correspondentes a 100%, 150% e 200% da dose prescrita (V100, V150 e V200, respectivamente) e as razões V150/V100 e V200/V100. RESULTADOS: Os volumes aumentaram com o aumento da extensão de carregamento dos cateteres, profundidade de cálculo e angulação, com tendência a um aumento proporcionalmente menor para angulações maiores. As relações V150/V100 e V200/V100 foram, em geral, homogêneas, ao redor de 0,50 e 0,30, respectivamente. CONCLUSÃO: A distribuição de dose na situação considerada padrão é em geral adequada. Nenhum parâmetro específico que pudesse ser relacionado à maior toxicidade foi identificado. Recomendamos uma avaliação rápida da qualidade do implante por meio da análise das relações V150/V100 e V200/V100.

Emergent management of malignancy-related acute airway obstruction

Acute obstruction of the airway in the emergent situation results from a wide variety of malignant and benign disease processes. Acute management involves establishing a secure and patent route for adequate gas exchange. This requires rapid determination of the location of the obstruction and nature of the obstruction followed by a thoughtful management approach based on findings. Difficult anatomy, hemorrhage, dense secretions, inflammation, and bulky tumor mass can significantly complicate the task of clearing the airway. Obstruction of the central airways by malignant tumor is associated with poor prognosis, but quality of life is considerably improved by restoration of adequate central airways. For both the patient and the clinician, the presentation can be frightening, and advanced interventional pulmonary/endobronchial techniques are required to achieve prompt relief of symptoms. The alleviation of central airway obstruction by tumor is most often palliative, with improvement of quality of life the primary goal rather than cure. This review will cover covers an approach to the patient with airway obstruction that results from malignancy involving the trachea or proximal bronchial tree and affecting gas exchange.

Efficacy and toxicity of concomitant cisplatin with external beam pelvic radiotherapy and two high-dose-rate brachytherapy insertions for the treatment of locally advanced cervical cancer

OBJECTIVE

There is no standard high-dose-rate (HDR) brachytherapy dose for locally advanced cervical cancer. The objective of this study was to determine the efficacy, toxicity and clinicopathologic predictive markers affecting survival using cisplatin (CDDP) concomitant with external beam pelvic radiotherapy (EBRT) and two 9-Gy HDR insertions for the treatment of locally advanced cervical cancer.

METHODS

77 consecutive patients with Stage IB2-IV cervical cancer treated with CDDP, EBRT and two 9-Gy HDR insertions were included. Kaplan-Meier methods and Cox proportional hazards models were applied for survival statistics.

RESULTS

Median age was 53. 90% had squamous cell carcinoma. Median follow-up time was 3.5 years (range 0.5-12 years). Overall 5-year progression-free survival (PFS) was 75%. Local control rate and 5-year PFS were 88% and 83%, respectively, for Stages IB2/II, and 68% and 61%, respectively, for Stages III/IV. Grade 3/4 GI symptoms were the most common acute side effects (47%). Grade 3/4 late toxicities occurred in five (6%) patients.

CONCLUSIONS

HDR brachytherapy regimens consisting of two 9-Gy HDR insertions have similar efficacy and side effect profiles as other brachytherapy regimens for the treatment of cervical cancer with improved safety and patient convenience.

Usefulness of mini-tracheostomy and torque controlled insertion of applicator in fractionated endobronchial brachytherapy

Endobronchial brachytherapy was developed as effective treatment of endobronchial cancer and fractionated schedule is applied to decrease late toxicity. However, repeated bronchofiberscopy is onerous to the patient and restricts the treatment schedule itself. We applied mini-tracheostomy for a ready access route, and a torque controlled technique for easy insertion of the endobronchial applicator. Eight patients with tracheobronchial cancer invasion were treated with endobronchial brachytherapy of 18-30 Gy/3-5 fractions/1.5-2.5 weeks (median 24 Gy/4 fractions/2 weeks) at reference points of 5 mm from the bronchial surface. The averaged individual irradiation and single session times were 4 min and 24 min, respectively. There were no procedure-related complications. These technical improvements may facilitate flexible fractionated dose prescriptions.

High dose rate brachytherapy: its clinical applications and treatment guidelines

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

Radiation treatment of lung cancer—Patterns of Practice in Canada

BACKGROUND AND PURPOSE

To assess the patterns of practice among Canadian radiation oncologists who treat lung cancers.

PATIENTS AND METHODS

A questionnaire detailing different aspects of radiation treatment of lung cancer was mailed to all radiation oncologists treating lung cancer in Canada. Seventy-two percent (74/103) of radiation oncologists who treat lung cancer from all 34 Canadian cancer centres replied to the questionnaire.

RESULTS

(a) Radiotherapy regimens in Canadian cancer centres are in accordance with several major randomised studies. There is still some variation in treatment practice that may be due to unresolved controversies or limited resources. The most frequently used prescription dose was 40Gy/15f/3w (where f stands for fractions and w stands for weeks) for small cell lung cancer (SCLC) and 60Gy/30f/6w for non-small cell lung cancer (NSCLC). If there were no resource constraints, 30% (22/74) and 20% (15/74) would prefer to use a different dose-fractionation scheme for SCLC and NSCLC, respectively; 95% (70/74) would prefer to use 3D-conformal or intensity-modulated radiotherapy. (b) Among the various modern technologies assessed by respondents, CT (computed tomography) simulator, multi-leaf collimator, on-line electronic portal imaging and PET (positron-emission tomography) scanning were rated the highest in terms of potential patient benefit. Discrepancy between demand and availability of technology was greatest for PET scanning.

CONCLUSIONS

Canadian practice in the treatment of lung cancers shows some variations although it is consistent with the trends in the literature. The lack of some modern technologies and human resources is an ongoing concern, especially the lack of PET imaging equipment.

Late urologic effects after adjuvant irradiation in stage I endometrial carcinoma

OBJECTIVES

To evaluate the incidence and type of incontinence after external beam radiotherapy (RT) and brachytherapy. Distinct late effects on the urinary bladder can occur and are frequently mild after adjuvant RT for Stage I endometrial carcinoma. Not all side effects that impair quality of life (eg, urinary incontinence) are classified in the commonly used grading system.

METHODS

Forty-one patients were evaluated for newly occurred urinary incontinence after adjuvant RT. The mean follow-up was 64.8 months, and the mean age was 62.1 years. The validated incontinence score from Gaudenz was used. Additionally, quality-of-life questions were asked.

RESULTS

Overall, 22 (53.7%) of 41 patients complained of urinary incontinence. Urge incontinence was classified in 45.5% (10 of 22 patients) and stress urinary incontinence in 54.5% (12 of 22 patients).

CONCLUSIONS

The onset of stress urinary incontinence after brachytherapy can be explained by anatomic findings, such as adverse affects to the nerve supply of the rhabdosphincter. According to our results, the exposure to additional external beam RT can cause urge incontinence. Patients and doctors must be aware that urinary incontinence, with an occurrence rate of more than 50%, represents the most common side effect after surgery and RT for Stage I endometrial carcinoma. We conclude that, depending on the type of RT, a stress incontinence rate of 24.4% and an urge incontinence rate of 29.2% is possible.

Stage IIB-IVA Cancer of the Cervix

Stage IIB-IVA cancer of the cervix represents locally advanced-stage disease that has extended beyond the cervix without clinical evidence of extrapelvic metastasis. Localized surgery is seldom used as the extent of the disease precludes and an adequate surgical margin. Both sophisticated imaging and surgical staging have been utilized to accurately assess the extent of disease for treatment planning. Careful attention to radiation technique and the use of brachytherapy impact survival and treatment morbidity. Concurrent cisplatin-based chemotherapy has become the accepted standard based on randomized clinical trials (level 1 evidence). Further improvements may be achieved with combination chemotherapy, hyperthermia or prophylactic extended field radiation. However, these improvements, currently practiced in developed countries, must be implemented in underdeveloped countries which have the greatest burden of this disease.

Assessment of the scope and quality of clinical practice guidelines in lung cancer

STUDY OBJECTIVES

To provide an evidence-based background for developing the American College of Chest Physicians (ACCP) lung cancer guidelines, a systematic review of the literature was performed to identify published lung cancer guidelines and evaluate their quality.

DESIGN, SETTING, AND PARTICIPANTS

A systematic search was performed for relevant literature from MEDLINE, Cancerlit, CINAHL, HealthStar, the Cochrane Library, and the National Guidelines Clearinghouse published from January 1989 to July 2001.

MEASUREMENT AND RESULTS

From 369 citations, 51 relevant guidelines were identified. Each guideline was evaluated by at least four reviewers using the Appraisal of Guidelines for Research and Evaluation (AGREE) instrument and was coded for clinical topics covered. The recommendations included in each guideline also were abstracted. Of the 51 guidelines evaluated, 27 (53%) were evidence-based. Clinical topics identified by the ACCP for their guideline effort each were represented by at least one existing guideline. Of the 880 clinical recommendations abstracted from the guidelines, only 253 (29%) were evidence-based. The AGREE instrument rates guidelines along six domains. As a group, the guidelines performed well in the scope and purpose domain, with only six guidelines (12%) scoring < 50%. For the remaining domains, however, the guidelines did not perform as well, as follows: for stakeholder involvement, 41 guidelines (80%) scored < 50%; for rigor of development, 29 guidelines (57%) scored < 50%; for clarity and presentation, 17 guidelines (33%) scored < 50%; for applicability, 46 guidelines (90%) scored < 50%; and for editorial independence, 47 guidelines (92%) scored < 50%. After considering the domain scores, the reviewers recommended only 19 of the guidelines (37%).

CONCLUSIONS

All major clinical lung cancer topics are covered by at least one guideline, but no single guideline addresses all areas. Furthermore, although existing guidelines may accurately reflect clinical practice, most performed poorly when evaluated for quality. Future guideline efforts that address each item of the AGREE instrument would add substantially to the literature.

Postoperative irradiation in endometrial cancer: still a matter of controversy

Although endometrial cancer is the most common female malignancy, evidence-based uniform guidelines for postoperative therapy have not been established. The most logical management is adjuvant irradiation tailored to the extent of surgery, the tumour grade, depth of myometrial invasion, degree of lymph node involvement and age of the patient. Currently, the only widely accepted treatment recommendations are no further therapy in low-risk patients who underwent extensive surgical staging, and external beam radiotherapy (EBRT) in high-risk patients. Most authors recommend postoperative application of only one radiotherapy modality: either brachytherapy (BRT) or EBRT, as their routine combination does not clearly improve the outcome but does increase the risk of late complications. A combination of BRT and EBRT should however be considered in patients with stage II disease, for infiltration of the lower uterine segment, vaginal involvement, positive or close surgical margins, capillary space involvement or unfavourable histology. Two recent randomized studies including mostly intermediate-risk patients managed with either extensive surgical staging or total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH&BSO) with or without postoperative EBRT, showed better local control but no survival benefit from adjuvant irradiation. Two ongoing Gynecologic Oncology Group (GOG) studies compare adjuvant chemotherapy with pelvic or abdominal irradiation in patients with high risk of local relapse. The role of adjuvant radiotherapy (EBRT with or without BRT) in high-risk patients as well as the value of lymphadenectomy in patients fit for such surgery is being addressed in a trial co-ordinated by the Medical Research Council. Future studies are warranted to define whether any irradiation should be employed in intermediate-risk patients and which radiotherapy modality should be used in high-risk node-negative patients with stage I tumours (stage Ib grade 3 and all stage Ic). Other issues which should be addressed in future studies include the extent of surgery, the role of systemic therapies, the relevance of novel biologic prognostic factors, salvage therapies after recurrence, cost-benefit analysis and quality of life.

Australian high-dose-rate brachytherapy protocols for gynaecological malignancy

There is no consensus over the optimal dose fractionation schedules for high-dose-rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians.

The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix

PURPOSE

This report presents guidelines for using high-dose-rate (HDR) brachytherapy in the management of patients with cervical cancer, taking into consideration the current availability of resources in most institutions.

METHODS

Members of the American Brachytherapy Society (ABS) with expertise in HDR brachytherapy for cervical cancer performed a literature review, supplemented their clinical experience to formulate guidelines for HDR brachytherapy of cervical cancer.

RESULTS

The ABS strongly recommends that definitive irradiation for cervical carcinoma must include brachytherapy as a component. Each institution should follow a consistent treatment policy when performing HDR brachytherapy, including complete documentation of treatment parameters and correlation with clinical outcome, such as pelvic control, survival, and complications. The goals are to treat Point A to at least a total low-dose-rate (LDR) equivalent of 80-85 Gy for early stage disease and 85-90 Gy for advanced stage. The pelvic sidewall dose recommendations are 50-55 Gy for early lesions and 55-65 Gy for advanced ones. The relative doses given by external beam radiation therapy (EBRT) vs. brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional preference. As with LDR brachytherapy, every attempt should be made to keep the bladder and rectal doses below 80 Gy and 75 Gy LDR equivalent doses, respectively. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. While recognizing that many efficacious HDR fractionation schedules exist, some suggested dose and fractionation schemes for combining the EBRT with HDR brachytherapy for each stage of disease are presented. These recommendations are intended only as guidelines, and the suggested fractionation schemes have not been thoroughly tested. The responsibility for the medical decisions ultimately rests with the treating radiation oncologist.

CONCLUSION

Guidelines are established for HDR brachytherapy for cervical cancer. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose-reporting policies. These guidelines will be modified, as image-based treatment becomes more widely available.

Treatment of roentgenographically occult endobronchial carcinoma with external beam radiotherapy and intraluminal low-dose-rate brachytherapy: second report

PURPOSE

To evaluate the efficacy and toxicity of treatment with external beam radiotherapy and intraluminal low-dose-rate brachytherapy for roentgenographically occult endobronchial carcinoma (ROEC).

METHOD AND MATERIALS

A total of 79 lesions (71 cases) of ROEC were treated with external beam radiotherapy and intraluminal low-dose-rate brachytherapy from July 1991 to December 1998. Of these lesions, 68 (64 cases) were treated with our standard dose (external beam radiotherapy of 40 Gy and intraluminal low-dose-rate brachytherapy of 25 Gy) and are the subject of this report. All 64 patients were males, and their ages ranged from 55 to 80 (median, 68) years. The histologic diagnosis was squamous cell carcinoma in all patients.

RESULTS

In all cases, the scheduled treatment was carried out within 2 months. Follow-up period ranged from 4 to 91 (median, 44) months from the beginning of this treatment. Acute toxicity was tolerable. Grade 2 radiation pneumonitis was observed in 4 cases, and there was no case of greater than Grade 2 radiation fibrosis. Nineteen cases of bronchial stenosis and 23 cases of bronchial obstruction were observed on follow-up bronchoscopy. However, no Grade 2 or greater deterioration of respiratory function due to radiotherapy, prolonged symptoms, or fatal toxicity was observed. Nine patients suffered recurrence, 5 of whom were rescued by surgery and external beam radiotherapy, and 4 of whom died of disease. The 5-year cause-specific survival, overall-survival, and disease-free rate were 96.1%, 72.3%, and 87.3%, respectively.

CONCLUSION

Combined treatment with external beam radiotherapy and intraluminal low-dose-rate brachytherapy is effective and results in acceptable complications for ROEC.

Surgical palliation of airway obstruction resulting from lung cancer

Bronchogenic carcinoma remains a relentless plague of modern society causing far more deaths than the well-popularized "AIDS epidemic" and secondary only to cardiovascular disease as a cause of death in America. Despite medical advances and treatment breakthroughs, only 40% of newly identified lung cancer patients are "potentially curable". Therefore, a large portion of this patient population will require palliative care and treatment. Surgical palliation is somewhat a misnomer in that most endobrachial lesions causing significant obstruction that result in dyspnea are not amenable to surgical intervention, i.e., operative resectional therapy. The palliative management options of airway obstruction resulting from advanced stage lung cancer will be reviewed, including the historical aspects, development and current use of laser resection, airway stenting, and endobrachial brachytherapy for management of unresectable airway tumors. These modalities frequently are used simultaneously in the same patient and may be used in conjunction with current chemotherapeutic and conventional external-beam radiation protocols.

Radiation therapy for roentogenographically occult lung cancer by external beam irradiation and endobronchial high dose rate brachytherapy

PURPOSE

We investigated the clinical usefulness of radiation therapy by external beam irradiation and endobronchial brachytherapy for the treatment of roentogenographically occult lung cancer.

PATIENTS AND METHODS

From 1995 to 1996, five patients were treated with radiation therapy. We analyzed their treatment outcomes. The follow-up period varied from 3.0 to 3.8 years or until death. External beam radiation (40 Gy/20 fractions/4 weeks) was delivered to the tumor site alone, and not prophylactically given to the mediastinum. Endobronchial brachytherapy using high dose rate iridium (Ir)-192 was concurrently administered principally to a total dose of 18 Gy on the bronchial mucosa in three weekly fractions of 6 Gy each.

RESULTS

Complete remission was obtained in all patients. Two patients died of intercurrent diseases at 12 and 21 months without any evidence of recurrence. The disease has been also controlled in the other three cases. With the above doses, three small tumors < 1 cm were controlled without adverse effect. In two tumors, the dose reference points were set 2-7 mm beneath the mucosa, and larger doses were administered by brachytherapy. An applicator acting as a spacer was not used in these cases. The tumors were controlled, although the irradiated bronchi showed severe stenosis in 6 months following the treatment. However, the patients were asymptomatic and did not need further intervention.

CONCLUSION

External beam irradiation combined with endobronchial brachytherapy was useful for the treatment of roentogenographically occult lung cancer as an alternative to surgery. Further investigation is needed to determine the optimal doses of radiation therapy.

Adjuvant high-dose rate brachytherapy with or without external beam radiotherapy post-hysterectomy for endometrial cancer

The purpose of this study was to evaluate patient selection, local control, survival and late toxicity of posthysterectomy adjuvant radiotherapy and compare adjuvant external beam therapy and high-dose rate (HDR) brachytherapy versus HDR brachytherapy alone. A retrospective analysis was performed on a series of 225 patients with endometrial cancer treated with external beam radiotherapy and HDR brachytherapy or HDR brachytherapy alone posthysterectomy from 1985 to June 1993. Of these 225 patients, 82 received external beam radiotherapy and brachytherapy and 143 received brachytherapy alone. The HDR fraction size was 8.5 Gy prescribed to the mucosal surface; two fractions were given after external beam and four fractions if brachytherapy alone was used. The median follow-up was 6.9 years. The patients who received combined external beam and brachytherapy had higher stage and grade tumors. The survival outcome was similar for either group when matched for stage. Overall relapse-free survival at five years was 96% and 81%, respectively for brachytherapy alone and combined adjuvant therapy. Pelvic recurrence was seen in 2.7% of patients. Toxicity was more common with external beam radiotherapy and brachytherapy compared to brachytherapy alone (45.1% vs 23.1%, P = 0.003). However, moderate or severe toxicity was rare but again was more common in the combined radiotherapy group (8.5% vs 2.1%, P = 0.04). There was a non-significant trend to increased toxicity after lymphadenectomy and external beam radiotherapy compared with patients who did not have a staging lymphadenectomy prior to external beam radiotherapy (62% vs 38%, P = 0.16). Adjuvant radiotherapy can be individualized and be based upon the information provided by the pathological specimens, which excluded external beam radiotherapy if a lymphadenectomy was performed and there was no evidence of extra-uterine disease. This study found more toxicity associated with adjuvant radiotherapy compared with other studies, but this may reflect different reporting criteria. There was more toxicity related to external beam radiotherapy and brachytherapy compared to brachytherapy alone. The two HDR brachytherapy protocols used in this series appear effective and safe.

The American brachytherapy society survey of brachytherapy practice for carcinoma of the cervix in the United States

PURPOSE

The purpose of this study was to survey the brachytherapy practice for cervical cancer in the United States.

METHODS

The Clinical Research Committee of the American Brachytherapy Society (ABS) performed a retrospective survey of individual physicians of the ABS and American Society of Therapeutic Radiologists and Oncologists regarding the details of the brachytherapy techniques they personally used in the treatment of cervical cancer patients for the year 1995. The replies (some of which may have been an estimate only) were tabulated. The scope of this survey did not allow us to verify the data by chart audits.

RESULTS

A total of about 3500 questionnaires were mailed out; 521 responses were received. Of these responders, 206 (40%) did not perform any brachytherapy for carcinoma of the cervix in 1995. Of the other 315 responders reporting a total of 4892 patients treated in 1995, 88% used low dose rate (LDR) while 24% used high dose rate (HDR). There was a wide variation in the doses used. For LDR treatments, the median total external beam radiation therapy (EBRT) dose was 45 and 50 Gy and the LDR dose was 42 and 45 Gy for early and advanced cancers, respectively. For HDR treatments, the median EBRT dose was 48 and 50 Gy and the median HDR dose was 29 and 30 Gy for early and advanced cancers, respectively. The median dose per fraction was 6 Gy for a median of five fractions. Interstitial brachytherapy was used as a component of the treatment in 6% of the patients by 21% of responders. Very few responders treated with pulsed or medium dose rates.

CONCLUSION

This retrospective survey showed the current brachytherapy practice pattern in the treatment of cervical cancer in the United States and can serve as a basis for future prospective national brachytherapy data registry. There was wide variation in the practice pattern, emphasizing the urgent need for consensus on these issues.

Late complications after postoperative radiotherapy in endometrial cancer: analysis of 317 consecutive cases with application of linear-quadratic model

PURPOSE

To evaluate the incidence and risk factors for late complications after postoperative radiotherapy in endometrial cancer patients.

METHODS AND MATERIAL

We performed a detailed retrospective analysis of 317 endometrial cancer patients given postoperative radiotherapy. A total of 247 patients (78%) received both intracavitary (BRT) and external beam irradiation (XRT); 49 patients (15%) received only BRT, and 21 (7%) only XRT. BRT included radium (Ra) and cesium (Cs). The mean dose rate for both isotopes at 0.5 cm from the applicator surface was 0.47 +/- 0.06 and 1.42 +/- 0.41 Gy/h, and the mean total dose was 50.5 +/- 10.3 and 48.4 +/- 15.0 Gy, respectively. Mean BRT dose at 0.5 cm was 50.1 +/- 11.7 Gy (range 14.5-71.0). Mean XRT dose in the International Commission on Radiation Units and Measurements (ICRU) reference point was 49.0 +/- 3.7 Gy (range 22.0-66.0) given in fractions of 1.54-2.49 Gy (mean 2.0 +/- 0.17) with a two- or four-field technique. Follow-up ranged from 4 to 21 years (median 7.3). Normalized total dose (NTD) including XRT and BRT doses was calculated based on a linear quadratic equation.

RESULTS

Five-year overall survival rate was 75%, and 5-year disease-free survival (censored for noncancer deaths) was 81%. Late radiotherapy complications of any grade occurred in 158 patients (51%), including bowel complications in 41% and urinary bladder complications in 21%. A total of 37 grade 3 or 4 complications were observed in 33 patients (11%), of whom 32 were treated with both XRT and BRT. Severe bowel and/or urinary bladder complications occurred in 24 patients: in 14 of 72 patients (19.4%) who received XRT and Cs BRT, and in 10 of 172 patients (6.0%) applied XRT and Ra BRT. The higher proportion of severe bowel and/or bladder complications in the former group was due to the particularly frequent rate of these events (30.0%) in a subset of 47 patients who received XRT combined with Cs BRT at the dose rate of 1.7 Gy/h and the total BRT dose of 60 Gy. Higher NTD, XRT fraction dose, BRT dose rate, Cs BRT, two-field XRT technique, short overall radiotherapy time, and older age were correlated with increased late-event risk in univariate analysis. Multivariate Cox analysis demonstrated that the independent risk factors for late bowel complications were NTD (p = 0.000) and BRT dose rate (p = 0.036), whereas for bladder complications they were BRT dose rate (p = 0.005) and XRT fraction dose (p = 0.041). Neither clinical factor (age, parity, prior abdominal surgery, FIGO stage, diabetes mellitus, or hypertension) nor the surgery-to-radiotherapy interval, nor overall radiotherapy time was independently associated with the risk of late bladder or bowel complications.

CONCLUSIONS

The risk of late complications after postoperative radiotherapy in endometrial cancer depends mainly on treatment-related factors: NTD, BRT dose rate, and XRT fraction dose. The use of combined XRT and BRT increases the risk of late effects. NTD calculations including BRT dose rate and XRT fraction dose enable estimation of radiobiologically equivalent dose and can decrease the risk of mistakes when the radiotherapy regimen is changed.

Brachytherapy in lung cancer

Brachytherapy, the direct application of a radioactive isotope into the tumor bed, delivers a high dose to the tumor as compared to the surrounding normal tissue. Interstitial brachytherapy, the placement of the isotope into a tumor bed where no lumen exists, has been described but is utilized infrequently in clinical practice. Endobronchial brachytherapy, the placement of the source within the airway lumen, as a boost to conventional external beam radiation has not yet demonstrated improved local tumor control or overall survival as compared to external beam alone in the definitive treatment of inoperable lung cancer. In the palliative setting, brachytherapy can provide prompt relief of obstructive symptoms and hemoptysis in the majority of patients.

High dose rate endobronchial brachytherapy using a new applicator

BACKGROUND AND PURPOSE

To obtain adequate spatial dose distribution for endobronchial brachytherapy, we applied reference dose points according to the bronchial diameter. For this purpose, we devised a new applicator of which the source transfer tube is contained in the center of the lumen for high dose rate (HDR) brachytherapy.

MATERIALS AND METHODS

Thirty-nine patients with endobronchial cancer underwent endobronchial brachytherapy using an HDR afterloading machine with an Ir-192 source. In the nine patients treated with curative intent, treatment consisted of external beam radiotherapy with 40-60 Gy for 4-6 weeks and endobronchial brachytherapy with three fractions of 6 Gy. The 30 patients treated with palliative intent received one fraction of 10 Gy with or without external beam irradiation. The reference dose points were prescribed according to bronchial diameter, which was measured by the applicator's radiopaque wing expansion reflecting the bronchial caliber.

RESULTS

The new applicator could be placed at the intended site in 37 lesions. Of 12 lesions which were treated with curative intent, eight (67%) disappeared after brachytherapy. The overall survival at 3 years of all patients and of the patients treated with curative intent was 22 and 64%, respectively.

CONCLUSIONS

The source should be positioned in the center of the lumen; this technique is helpful in reducing side-effects caused by inhomogeneous dose distribution of endobronchial brachytherapy.

Code of practice for brachytherapy physics: report of the AAPM Radiation Therapy Committee Task Group No. 56. American Association of Physicists in Medicine

Recommendations of the American Association of Physicists in Medicine (AAPM) for the practice of brachytherapy physics are presented. These guidelines were prepared by a task group of the AAPM Radiation Therapy Committee and have been reviewed and approved by the AAPM Science Council.

Isolated vaginal recurrences in endometrial carcinoma: treatment results using high-dose-rate intracavitary brachytherapy and external beam radiotherapy

PURPOSE

To evaluate the long-term disease control, survival and complication rates using high-dose-rate intracavitary brachytherapy (HDRB) and external beam radiotherapy (EBRT) for patients found to have isolated vaginal recurrences from early-stage endometrial adenocarcinoma following total abdominal hysterectomy and bisalpingo-oophorectomy (TAH BSO).

MATERIALS AND METHODS

Twenty patients originally diagnosed with early-stage endometrial adenocarcinoma (FIGO stage I or II) following TAH BSO developed isolated vaginal recurrences and were referred to our radiation oncology department for definitive treatment. The median time between TAH BSO and vaginal recurrence was 24 months. Thirteen patients received combined modality treatment (EBRT + HDRB) and seven patients received HDRB only. Median prescribed dose was 4400 cGy by EBRT and 2400 cGy to the vagina mucosa surface by HDRB in the combined modality group. Median prescribed dose was 3500 cGy to the vagina mucosa surface for the HDRB only group. These patients were followed for a median duration of 47.5 months following treatment for isolated vaginal recurrence.

RESULTS

Eighteen of 20 patients (90%) achieved a complete response to therapy and the remaining 2 achieved a partial response. Four of 18 complete responders developed a second recurrence within 30 months following radiotherapy. Ten-year cumulative local control rate was 74%. Ten-year cumulative cause specific and disease-free survival rate was 71 and 46%. Overall late complication rate was 15%; there were no grade 3 or 4 late complications. Three patients developed grade 2 late complications from treatment; all 3 were from the combined modality group (HDRB + EBRT).

CONCLUSION

The use of HDRB resulted in high complete response rates and durable long-term disease-specific survival in a substantial percentage of patients. To our knowledge, this study represents the first published results on treatment of vaginal recurrences with HDRB. Although the number of patients in this study is small, treatment results compare favorably to those obtained from patients treated with low-dose-rate brachytherapy +/- EBRT from other studies.

Does additional brachytherapy improve the effect of external irradiation? A prospective, randomized study in central lung tumors

PURPOSE

Endobronchial brachytherapy has become more widely used to increase the total local dose of irradiation ("boost") applied for the treatment of lung cancer. Apart from treatment for local stenosis, endobronchial brachytherapy in combination with external irradiation (EI) has the potential to improve local tumor control and perhaps prolong survival, but the real benefit has not been proven yet. To evaluate the possible effects of external irradiation with an additional boost of high dose rate (HDR) brachytherapy, we conducted a prospective randomized study.

METHODS AND MATERIALS

Design-two groups were compared: Group 1 was treated with external radiotherapy alone (planned dose 60 Gy); Group 2 received an additional boost of HDR brachytherapy of scheduled 4.8 Gy each (at 10 mm from the source axis) before and after external irradiation. Patients-98 patients with advanced inoperable lung cancer were included in the study, 42 in Group 1 and 56 in Group 2. Both groups were comparable with respect to age, sex, tumor stage, Karnofsky performance status (KPS), and histology.

RESULTS

A mean total external irradiation dose of 50.5 +/- 14.1 Gy in Group 1 and 50 +/- 12.5 Gy in Group 2 was applied. Group 2 received an additional dose of 7.44 +/- 2.6 Gy (at 10 mm depth) through brachytherapy. The median survival time in both groups was comparable (28 weeks and 27 weeks, respectively). In patients with squamous cell carcinoma (68 patients) Group 2 showed an advantage in median survival with borderline significance (40 vs. 33 weeks, p = 0.09). Group 2 showed also a better local tumor control in all patients; patients with squamous cell carcinoma had a significantly longer period of local tumor control. Fatal hemoptysis was the cause of death in 6 (14.2%) patients in Group 1 and 11 (18.9%) in Group 2 (p = 0.53).

CONCLUSIONS

High dose rate brachytherapy in patients with inoperable lung cancer increased local control in our randomized study when used in combination with external irradiation. Survival time was also longer, but with no clear statistical significance. This applied especially to patients with squamous cell carcinomas. There was no statistically significant difference in the incidence of fatal hemoptysis between the two groups.

Cost minimization analysis of various treatment options for surgical stage I endometrial carcinoma

PURPOSE

This study compares the payors' cost of treatment for surgical Stage I endometrial carcinoma with results of published clinical studies to determine which treatment most efficiently uses available resources.

METHODS AND MATERIALS

Six options for treatment of surgical Stage I endometrial carcinoma were selected for comparison. The treatment options were observation only, low-dose-rate brachytherapy (LDRB) (nonremote afterloading), LDRB and external beam radiation (EBRT), EBRT only, high-dose-rate brachytherapy (HDRB) only (three applications), and EBRT and HDRB (three applications). The literature was reviewed to obtain disease-free survival (DFS) rates corresponding to the treatment options chosen in surgical Stages IA, IB, and IC. Metaanalysis and sensitivity testing were performed on the collected clinical data. A typical midsized city in Medicare region IV was used as our representative payor cost basis.

RESULTS

Thirteen retrospective articles contained sufficient clinical information for analysis. Comparison of DFS between the observation, LDRB, and EBRT treatment groups was made for Stage IA; LDRB and EBRT for Stage IB; and LDRB, EBRT, LDRB +/- EBRT, LDRB + EBRT, and HDRB + EBRT for Stage IC. Meta-analysis failed to reveal statistically significant DFS between the respective treatment options within Stages IA, IB, or IC. The RVUs for each treatment option were LDRB, 21.7; EBRT, 117.1; EBRT + LDRB, 130.7; HDRB, 155.5; and EBRT + HDRB, 264.4. The DRG payment for LDRB is $2714.92. The calculated payor's cost for each treatment option was: LDRB, $3466.62; EBRT, $4053.03; EBRT + LDRB, $7238.55; HDRB, $5381.19; and EBRT + HDRB, $9153.14.

CONCLUSION

Our analysis reveals no statistically significant differences in DFS among the treatment options considered within each surgical stage. Observation appears to result in acceptable DFS with minimal cost in Stage IA. Low-dose-rate brachytherapy was the most cost-effective treatment in Stage IB, with no statistically significant difference in DFS between LDRB and EBRT. Although LDRB had inferior DFS compared to other treatment options in surgical Stage IC, this difference failed to reach statistical significance. Our analysis implies, excluding observation, that LDRB may be a more cost-efficient treatment than the other treatment options considered. Further studies stratifying for surgical stage and grade are needed to determine the optimal cost-effective treatment for this common malignancy.

Treatment of unresectable lung cancer with brachytherapy

Endobronchial brachytherapy is an evolving treatment modality. Although standard clinical indications and dosage schedules have not yet been established, the wide range of individual experience overwhelmingly demonstrates its efficacy in palliating lung cancer patients who generally have limited treatment options. Although the exact complication rate is not known, it appears to be low and the potential benefits far outweigh the risks. The role of endobronchial brachytherapy for cure is less clear. For most instances "prolonged palliation" would be a more suitable term than "cure." Further data is needed to clarify the proper place of endobronchial brachytherapy as a boost to external beam radiation therapy. The dose, fractionation scheme, and timing relative to external beam radiation therapy are based on institutional preference at this time. The historical evolution, treatment technique, results, and complications of endobronchial brachytherapy are reviewed here.

High dose rate (HDR) brachytherapy technique: for carcinoma of uterine cervix using Nucletron applicators

This study describes our existing treatment method for high dose rate (HDR) brachytherapy of carcinoma of uterine cervix using Nucletron applicators. Based on our clinical experience with low dose rate (LDR) brachytherapy since 1986, we deliver 40-45Gy by external and 30Gy by internal radiation therapy. The change in regimen using HDR brachytherapy is that internal radiation dose is given in 5 fractions at weekly intervals following external radiotherapy. We have analyzed the dosimetry of 20 patients; total of 100 treatments done at our center using ring-tandem (R-T) and ovoid-tandem (O-T) applicator combinations. Since O-T applicator has more flexibility of using desired tandem length and reduced rectum and bladder dose due to internal shielding inside the ovoids, we have made the transition from R-T to O-T combination of applicator. The dose volume histogram of the isodose curve indicates that there is an increase in isodose volume with the O-T applicator by as much as 1.5 times as compared to R-T applicator. In majority of the treatments, rectum and bladder doses are less than 70% of target dose, however in very few treatments, the bladder dose has increased to more than the target dose, in which case, the applicators were reseated and added more packing or reduced the dose per fraction, for better tolerance of late responding normal tissues. All our dose calculations are checked with an independent calculation method and agreement was obtained with in 5-7% discrepancy.(ABSTRACT TRUNCATED AT 250 WORDS)

The achievement of isoeffective bronchial mucosal dose during endobronchial brachytherapy

PURPOSE

The use of endobronchial brachytherapy in the treatment of lung cancer is increasing due to the more widespread availability of high dose rate afterloading equipment. The complications include small airway (segmental and small lobar bronchi) fibrosis, stenosis, and obstructive complications in addition to hemorrhage. A progressive reduction in the diameter of the bronchial lumen occurs at each division of the bronchial tree. If uniform dwell times along a bronchial catheter treatment length are used, this will result in higher doses being given to the bronchial mucosa in the distal part of the treatment volume where the brachytherapy source mucosa distances are smaller, and underdosage proximally, where the source mucosa distances are larger.

METHODS AND MATERIALS

The known mathematical relationships of the sequential reductions in the diameter of the bronchial lumen have been incorporated into two methods of optimization, which have been compared to uniform dwell times along a treatment length from trachea to segmental bronchus.

RESULTS

The resulting isodose plots are presented, and demonstrate the extent of the overdosage distally, and the underdosage proximally when using uniform dwell times, and the achievement of isoeffective mucosal doses when using differential dwell times.

CONCLUSION

This refinement in brachytherapy technique offers the potential for reduced normal tissue complications and possibly improved tumor control by reducing overdosage and underdosage, respectively.

Palliative endobronchial brachytherapy for central lung tumors. A prospective, randomized comparison of two fractionation schedules

AIM OF THE STUDY

Remote high dose rate brachytherapy is an effective local treatment modality for central lung tumors and has the potential to improve survival time. Optimal dose and fractionation schemes have not been identified yet. We conducted a prospective randomized study to compare two treatment schedules in terms of survival time, local tumor control, and possible complications.

DESIGN

Group 1 received 4 brachytherapies with a dose of 3.8 Gy (at a 10-mm depth) on a weekly basis, and group 2 received 2 treatments with 7.2 Gy (at a 10-mm depth) at a 3-week interval. At a depth of 5 mm, the calculated doses would be 8 and 15 Gy. This study is still ongoing. Here we report interim results.

PATIENTS

Ninety-three patients with advanced cancer were included in the study; 44 were in group 1 and 49, in group 2. Both groups were comparable regarding age, sex, tumor stage, Karnofsky performance status, and histologic findings.

INTERVENTIONS

A mean total irradiation dose of 13.4 +/- 5.2 Gy for group 1 and 13.7 +/- 4.4 for group 2 were applied (calculated at 10 mm from the source axis, equivalent to 27.9 Gy in group 1 and 28.5 Gy in group 2 at a 5-mm depth).

RESULTS

The 1-year survival rate was 11.4% in group 1 and 20.4% in group 2. No significant difference in survival time was found, but mean survival was longer in group 2 (49 weeks) than in group 1 (26 weeks). Local control after 3 months was comparable in both groups. Fatal hemoptysis occurred at a similar rate in group 1 (22.2%) and in group 2 (21.1%).

CONCLUSION

High-dose rate brachytherapy with 2 x 7.2 Gy with a 3-week interval is equivalent to a 4 x 3.8-Gy regimen on a weekly basis. The shorter treatment schedule is more convenient for patients, does not cause more side effects, and provides an equal local tumor control.