Intraoperative high-dose-rate brachytherapy for pediatric solid tumors: a 10-year experience

Brachytherapy for rhabdomyosarcoma: Survey of international clinical practice and development of guidelines

BACKGROUND AND PURPOSE

The purpose of this study was to address the lack of published data on the use of brachytherapy in pediatric rhabdomyosarcoma by describing current practice as starting point to develop consensus guidelines.

MATERIALS AND METHODS

An international expert panel on the treatment of pediatric rhabdomyosarcoma comprising 24 (pediatric) radiation oncologists, brachytherapists and pediatric surgeons met for a Brachytherapy Workshop hosted by the European paediatric Soft tissue Sarcoma Study Group (EpSSG). The panel's clinical experience, the results of a previously distributed questionnaire, and a review of the literature were presented.

RESULTS

The survey indicated the most common use of brachytherapy to be in combination with tumor resection, followed by brachytherapy as sole local therapy modality. HDR was increasingly deployed in pediatric practice, especially for genitourinary sites. Brachytherapy planning was mostly by 3D imaging based on CT. Recommendations for patient selection, treatment requirements, implant technique, delineation, dose prescription, dose reporting and clinical management were defined.

CONCLUSIONS

Consensus guidelines for the use of brachytherapy in pediatric rhabdomyosarcoma have been developed through multicenter collaboration establishing the basis for future work. These have been adopted for the open EpSSG overarching study for children and adults with Frontline and Relapsed RhabdoMyoSarcoma (FaR-RMS).

Brachytherapy for Organ and Function Preservation in Soft-Tissue Sarcomas in Adult and Paediatric Patients

Adjuvant radiotherapy is an integral component in the management of soft-tissue sarcomas. Brachytherapy is a very convenient and conformal way of delivering adjuvant radiotherapy in such tumours, which spares the surrounding normal tissue. Randomised studies have established the efficacy of brachytherapy in the adjuvant setting, with a 5-year local control of 80-85%. High dose rate, low dose rate and pulsed dose rate have shown equivalent local control, but high dose rate has gained popularity owing to patient convenience, radiation safety and flexibility in dose optimisation. Freehand insertion perioperative brachytherapy (intraoperative placement and postoperative treatment) is the most commonly used technique in soft-tissue sarcomas, with intraoperative radiotherapy and radioactive seed placement being the less commonly used techniques. Brachytherapy can be used as monotherapy or in combination with external beam radiotherapy, such as in cases of close/positive margins for safe dose escalation. Although the quantum of side-effects with external beam radiotherapy has considerably reduced with the evolution of technology and the introduction of intensity modulation (intensity-modulated radiotherapy), brachytherapy still scores better in terms of dose conformality, especially in recurrent tumours (previously irradiated) and when used to treat paediatric and geriatric patients.

Brachytherapy in children, adolescents, and young adults: An underutilized modality in the United States?

BACKGROUND

Brachytherapy (BT) delivers highly conformal radiation and spares surrounding tissues, which may limit late effects in pediatric, adolescent, and young adult (AYA) patients. We aimed to characterize trends in BT use for this population in the United States, focusing on patients with rhabdomyosarcoma (RMS).

METHODS

The National Cancer Database was queried to identify patients ≤ 21 who were treated for solid tumor malignancies in the United States from 2004 to 2016. We obtained disease, treatment, and outcome data for patients treated with BT, in particular for RMS.

RESULTS

99 506 pediatric and AYA patients met study inclusion. Of these, 22 586 (23%) received radiation therapy (external beam radiation therapy [EBRT] and/or BT) and 240 (0.2%) received BT. Among patients treated with BT, 139 (58%) underwent surgery and 58 (24%) received EBRT. A total of 3836 patients were treated for RMS during this period. Of these, 2531 (66%) received any radiation and 37 (1%) received BT (EBRT + BT in 3, BT in 34). Of patients treated with BT for RMS, 28 (76%) underwent surgery + BT. Survival data were available for 31 patients treated with BT for RMS. With a median follow-up of 63 months, overall survival was 100% for patients with RMS of a favorable site treated with BT.

CONCLUSIONS

BT is rarely used to treat pediatric and AYA patients in the United States. Patients treated with BT for RMS experienced favorable survival, suggesting that this approach may not compromise oncologic outcomes and warrants further study as a therapeutic option in pediatric and AYA patients, specifically in RMS.

ACR-ABS-ASTRO practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy

PURPOSE

This practice parameter aims to detail the processes, qualifications of personnel, patient selection, equipment, patient and personnel safety, documentation, and quality control and improvement necessary for an HDR brachytherapy program.

METHODS AND MATERIALS

This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Brachytherapy Society (ABS), and the American Society for Radiation Oncology (ASTRO).

RESULTS

Brachytherapy is a radiotherapeutic modality in which radionuclide or electronic sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. Brachytherapy alone or combined with external beam radiotherapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides, such as iridium-192, at dose rates of ≥12 Gy/hr to a designated target point or volume, and it is an important treatment for a variety of malignant and benign conditions. Its use allows for application of high doses of radiation to defined target volumes with relative sparing of adjacent critical structures.

CONCLUSIONS

HDR brachytherapy requires detailed attention to personnel, equipment, patient and personnel safety, and continuing staff education. Coordination between the radiation oncologist and treatment planning staff and effective quality assurance procedures are important components of successful HDR brachytherapy programs.

Role and toxicity of radiation therapy in neuroblastoma patients: A literature review

Neuroblastoma is the most common extracranial solid tumor, arising from primitive sympathetic ganglion cells, in pediatric patients. The unique features of neuroblastoma include variable clinical behaviors, such as rapid progression to death and maturation to benign ganglioneuroma, followed by regression. Radiation therapy (RT) is usually administered to both the primary tumor bed and persistent metastatic sites after induction chemotherapy for high-risk neuroblastoma. RT to the tumor bed after surgical resection contributes significantly to local disease control and prevention of local relapse, confirming the role of RT. Palliative radiotherapy for metastatic neuroblastoma is also effective and safe and mainly provides symptomatic relief. The late side effects of RT in neuroblastoma patients include growth and developmental failure, hypothyroidism, gastrointestinal dysfunction, neurocognitive defects, pulmonary and cardiac abnormalities, infertility, and secondary cancers. In this article, we reviewed the role and toxicity of RT in neuroblastoma patients.

The American College of Radiology and the American Brachytherapy Society practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy

Brachytherapy is a radiation therapy method in which radionuclide sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. This practice parameter refers only to the use of radionuclides for brachytherapy. Brachytherapy alone or combined with external beam therapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides such as iridium-192 at dose rates of 20 cGy per minute (12 Gy per hour) or more to a designated target point or volume. High-dose-rate (HDR) brachytherapy is indicated for treating malignant or benign tumors where the treatment volume or targeted points are defined and accessible.

Intraoperative radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

Intraoperative phosphorus-32 brachytherapy plaque for multiply recurrent high-risk epidural neuroblastoma

Achieving local control is a crucial component in the management of neuroblastoma, but this may be complicated in the setting of prior radiation treatment, especially when the therapeutic target is in proximity to critical structures such as the spinal cord. The authors describe a pediatric patient with multiply recurrent neuroblastoma and prior high-dose radiation therapy to the spine who presented with progressive epidural disease. The patient was managed with resection and intraoperative high-dose-rate brachytherapy using a phosphorus-32 ((32)P) plaque previously developed for the treatment of brain and spine lesions.

Local control, survival, and operative morbidity and mortality after re-resection, and intraoperative radiation therapy for recurrent or persistent primary high-risk neuroblastoma

BACKGROUND/PURPOSE

Patients with locally recurrent or persistent high-risk neuroblastoma are difficult to treat. We describe our experience using intraoperative radiation therapy (IORT) after re-resection in this high-risk population.

METHODS

We retrospectively reviewed 44 consecutive patients who received IORT at our institution between April 2000 and September 2009 after gross total resection of recurrent/persistent tumor. Specifically, we evaluated local recurrence rates, complications, and overall survival.

RESULTS

The median age at diagnosis was 41.5 months. Median follow-up after IORT was 10.5 months. Each patient received prior chemotherapy and surgery, while 94.5% had previous external beam radiation therapy. MYCN was amplified in 34% of patients. There were no operative or postoperative deaths, and 18 patients (40.9%) had postoperative complications. There was a 50.4% probability of local control. MYCN amplification did not affect local control (local recurrence rate of 53.9% vs 52.4%, P = .89). Median overall survival was 18.7 months (95% confidence interval, 11.7-25.6 months). Mean survival for MYCN-amplified patients was 13.0 vs 39.2 months for those without MYCN amplification (P = .035).

CONCLUSIONS

Intraoperative radiation therapy after re-resection of locally recurrent/persistent neuroblastoma results in a reasonable rate of local control with acceptable morbidity and survival. This approach should be considered in this high-risk population.

A single-institutional brachytherapy experience in the management of esophageal cancer

PURPOSE

The aim of this work was to analyze the efficacy of high-dose-rate brachytherapy in the management of patients with esophageal cancer.

METHODS AND MATERIALS

Between 2001 and 2008, 104 patients (88 males and 16 females) received a brachytherapy treatment as a part of a personalized multimodal approach. The median age was 72 years, and the median Karnofsky performance status was 60. Brachytherapy was used in different situations: to complete a primary treatment with radical intent in patients not suitable for surgery; to control local recurrences; or to obtain a rapid and durable palliation of dysphagia in patients with metastases or in poor general condition. In selected cases, endoscopic ultrasound images were integrated in treatment planning procedure to obtain a more accurate volume definition. Efficacy in controlling dysphagia was assessed 1 month after brachytherapy.

RESULTS

Fifty-one patients received a radical treatment, and 53 patients were treated to relieve the symptoms. The median overall survival was 20.8 months. Lymph node involvement was found to be a significant prognostic factor for overall survival and dysphagia. Dysphagia was controlled in 88 patients (84.6%), and the median dysphagia-free interval was 17.5 months. Early and late adverse events were generally mild to moderate. The most severe effects were esophagotracheal fistulas, observed in 3 patients.

CONCLUSIONS

Brachytherapy has an important role in the management of esophageal cancer with a low rate of complications. endoscopic ultrasound-assisted treatment planning can be useful for a better individualization of curative treatments.

intraoperative radiation therapy part 2. Clinical results

Intraoperative radiation therapy (IORT) has been used for over 30 years in Asia, Europe and America as a supplementary activity in the treatment of cancer patients with promising results. Modern IORT is carried out with electron beams (IOERT) produced by a linear accelerator generally used for external beam irradiation (EBRT) or a specialized mobile electron accelerator. HDR brachytherapy (HDR-IORT) has also been applied on selected locations. Retrospective analysis of clinical experiences in cancer sites such as operable pancreatic tumour, locally advanced/recurrent rectal cancer, head and neck carcinomas, sarcomas and cervical cancer are consistent with local tumour control promotion compared to similar clinical experiences without IORT. New emerging indications such as the treatment of breast cancer are presented. The IORT component of the therapeutical approach allows intensification of the total radiation dose without additional exposure of healthy tissues and improves dose-deposit homogeneity and precision. Results of the application of IORT on selected disease sites are presented with an analysis on future possibilities. To improve the methodology, clinical trials are required with multivariate analysis including patient, tumour and treatment characteristics, prospective evaluation of early and late toxicity, patterns of tumour recurrence and overall patient outcome.

The challenging role of radiation therapy for very young children with rhabdomyosarcoma

PURPOSE

To evaluate local control and toxicity for very young children treated with multimodality therapy for rhabdomyosarcoma (RMS).

METHODS AND MATERIALS

From 1990 to 2004, 20 patients<or=36 months at diagnosis were treated at our institution. Nineteen underwent chemotherapy (CMT), surgery and/or intraoperative high-dose-rate brachytherapy (IOHDR), and external-beam radiation (EBRT). Median age was 17 months. Sites included extremity (7), trunk (5), parameningeal (4), orbit (1), head/neck (1), bladder/prostate (1). Histologies consisted of 10 embryonal (53%) and 9 alveolar/undifferentiated (47%). Ten had delayed gross total resection (GTR) at median time of 17 weeks after the start of CMT, and 8 of these underwent IOHDR. Median interval between start of CMT and EBRT was 18 weeks. Median EBRT dose was 36 Gy. EBRT technique was either intensity-modulated (11), three-dimensional (3), or two-dimensional (5). Functional outcome was assessed for patients alive>or=1 year after diagnosis (15) in terms of mild, moderate, or severe deficits.

RESULTS

Median follow-up was 33 months for survivors and 23 months for all patients. Two-year actuarial local control, event-free survival, disease-specific survival, and overall survival were 84%, 52%, 74%, and 62%, respectively. All patients who began EBRT<or=18 weeks after the start of CMT had their disease controlled locally. Five have mild deficits and 10 have no deficits.

CONCLUSIONS

A reduced dose of 36-Gy EBRT after delayed GTR may maximize local control while minimizing long-term sequelae for very young children with RMS, but unresectable tumors (e.g., parameningeal) require higher doses. Normal-tissue-sparing techniques such as intensity-modulated radiation therapy and IOHDR are encouraged. Local control may be maximized when EBRT begins <or=18 weeks after initiation of CMT, but further study is warranted. Longer follow-up is required to determine the full extent of late effects.

Use of brachytherapy in children with cancer: the search for an uncomplicated cure

Brachytherapy is a sophisticated radiation method in which radioisotopes are placed inside or at a short distance from the tumour. The volume of tissue that receives the prescribed dose of radiotherapy is therefore fairly small compared with that used in standard radiotherapy techniques. In paediatric oncology, this method of radiation delivery can have a favourable effect on several undesirable long-term side-effects that sometimes develop in children who receive radiotherapy, such as growth retardation and development of second primary tumours. Here, we describe the rationale for use of brachytherapy in children with cancer, the methods of the different brachytherapy techniques available, and the results obtained with several brachytherapy regimens in expert institutions throughout the world.

[Brachytherapy for soft tissue sarcomas. Technique and therapeutic indications]

The role of brachytherapy in the therapeutic strategy of soft tissue sarcomas has been difficult to assess due to the fact it has been during a long time institution-specific. However, the experience gained specially with low dose-rate treatments has allowed formulating guidelines for technical rules and patient selection. Brachytherapy used as an isolated treatment combined with surgery has proven to be effective in high-grade sarcomas, compared to surgery alone, in a unique randomized trial. Beside, a number of data have shown that the combination of brachytherapy and external beam irradiation could be superior to brachytherapy or external beam irradiation alone in the treatment of tumors with high-grade, or central location, locally advanced or on contact with neurovascular structures. Brachytherapy alone, combined with surgery, is of interest for conservative treatment of recurrent sarcomas occurring in previously irradiated areas. The occurrence of side effects remains acceptable if technical guidelines are followed, for surgery as well as for brachytherapy, using the most modern available treatment techniques. Brachytherapy should be at the moment an integrated part of the multidisciplinary treatment of soft tissue sarcomas.

Current challenges in Wilms' tumor management

Wilms' tumor is a renal cancer that predominantly affects children during the first 2 years of life. The continuing success of clinical trials in Wilms' tumor patients over the past 30 years has led to an overall survival of 85%, and treatment-related morbidity has been reduced. Less-aggressive chemotherapeutic regimes are available for patients with validated good prognostic factors, such as low stage and favorable histology. It is becoming increasingly apparent that treatment can be optimized through stratification of patients according to tumor stage and histology. Established treatments for Wilms' tumor include perioperative vincristine and actinomycin, with or without doxorubicin or radiotherapy. Relapsed patients have the option of salvage chemotherapy with ifosfamide, carboplatin and etoposide, as well as high-dose chemotherapy regimes and autologous hemopoietic stem-cell rescue. Further research is required to refine these regimes and identify further the role of additional prognostic factors in this childhood disease. In this article we discuss the most-debated issues and advances that have been made in the management of Wilms' tumor.

Feasibility report of conservative surgery, perioperative high-dose-rate brachytherapy (PHDRB), and low-to-moderate dose external beam radiation therapy (EBRT) in pediatric sarcomas

PURPOSE

This study was undertaken to determine the feasibility of perioperative high-dose-rate brachytherapy (PHDRB) as an accelerated boost in patients with pediatric sarcomas.

METHODS AND MATERIALS

Five pediatric patients (ages 7-16) with soft tissue sarcomas (STS) or soft tissue recurrences of previously treated osteosarcomas were treated with surgical resection and PHDRB (16-24 Gy) for R0-R1 resections. Patients with STS and osteosarcomas received 27 Gy and 45 Gy of EBRT postoperatively.

RESULTS

After a median follow-up of 27 months (range, 12-50) all the patients remain locally controlled. Only 1 patient developed regrowth of pulmonary metastases and died of distant disease at 16 months.

CONCLUSIONS

The use of PHDRB is safe in the short-term in this pediatric population. Only 1 patient suffered a partial wound dehiscence that may not be entirely related to PHDRB. Patients with recurrent osteosarcomas can be treated in a fashion similar to their adult soft tissue counterparts and avoid limb amputation. Younger patients with STS may achieve local control and prevent growth retardation with a combination of PHDRB and moderate doses of EBRT.

Brachytherapy for pediatric tumors

PURPOSE

Pediatric tumors are generally managed with a multi-modality treatment program that includes surgery, chemotherapy, and teletherapy. The use of teletherapy in young children can result in significant long-term toxicity (especially retardation of growth of bones and organs). The use of brachytherapy is an attractive alternative because brachytherapy irradiates small volumes and can thus potentially minimize complications.

METHODS AND MATERIALS

The brachytherapy techniques used are similar to those used in adults. Low-dose-rate brachytherapy with manually-afterloaded removable 192Ir is commonly used though it is associated with some radiation exposure hazards. Low energy radionuclides and remote afterloading technology have been used to reduce the radiation exposure hazards. Teletherapy is often added in the treatment of more extensive tumors, especially in older children.

RESULTS

Brachytherapy (as the sole radiation modality) to small volumes in conjunction with chemotherapy and surgery has produced good local control with growth preservation and acceptable late complications in selected patients with localized tumors.

CONCLUSION

Brachytherapy increases local control with a decrease in the probability of late complications (especially altered bone and organ growth) in comparison to EBRT. Low energy radionuclides and remote afterloading technology (HDR, IOHDR, and PDR) have been used to extend treatment to infants and younger children while reducing the radiation exposure to patients, family, and medical personnel.