Preliminary results of phase I/II study of high-dose-rate intraoperative radiation therapy for pediatric tumors

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.

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.

Long-Term Outcome and Toxicities of Intraoperative Radiotherapy for High-Risk Neuroblastoma

PURPOSE

To review a historical cohort of consecutively accrued patients with high-risk neuroblastoma treated with intraoperative radiotherapy (IORT) to determine the therapeutic effect and late complications of this treatment.

METHODS AND MATERIALS

Between 1986 and 2002, 31 patients with newly diagnosed high-risk neuroblastoma were treated with IORT as part of multimodality therapy. Their medical records were reviewed to determine the outcome and complications. Kaplan-Meier probability estimates of local control, progression-free survival, and overall survival at 36 months after diagnosis were recorded.

RESULTS

Intraoperative radiotherapy to the primary site and associated lymph nodes achieved excellent local control at a median follow-up of 44 months. The 3-year estimate of the local recurrence rate was 15%, less than that of most previously published series. Only 1 of 22 patients who had undergone gross total resection developed recurrence at the primary tumor site. The 3-year estimate of local control, progression-free survival, and overall survival was 85%, 47%, and 60%, respectively. Side effects attributable to either the disease process or multimodality treatment were observed in 7 patients who developed either hypertension or vascular stenosis. These late complications resulted in the death of 2 patients.

CONCLUSIONS

Intraoperative radiotherapy at the time of primary resection offers effective local control in patients with high-risk neuroblastoma. Compared with historical controls, IORT achieved comparable control and survival rates while avoiding many side effects associated with external beam radiotherapy in young children. Although complications were observed, additional analysis is needed to determine the relative contributions of the disease process and specific components of the multimodality treatment to these adverse events.

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.

Intraoperative radiation therapy first part: rationale and techniques

Intraoperative radiotherapy (IORT) is a technique where a high, single-fraction radiation dose is delivered during a surgical procedure to macroscopic tumours or tumour beds with minimal exposure of surroundings tissues which are displaced and shielded during the procedure. In this paper, the rationale for and use of IORT, both with electron beams (IOERT) and high-dose-rate brachytherapy (HDR-IORT) are discussed. For most tumours, the likelihood of obtaining local control (LC) improves when increasing doses can be administered. In many clinical situations, however, the dose that can be delivered safely to the tumour target is limited by the risk of damaging normal tissues. Special consideration is therefore given on this paper to the relationship between dose, LC and possible complications. Criteria for patient's selection and evaluation and information on sequencing and techniques are presented as well as some considerations on the need for a proper programme on quality assurance and periodical reporting of data.

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.

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.

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.

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

PURPOSE

To evaluate the efficacy and toxicity of intraoperative high-dose-rate brachytherapy (IOHDR) in the management of pediatric solid tumors.

METHODS AND MATERIALS

The records of 66 pediatric patients who underwent IOHDR for a solid tumor from February 1993 through December 2002 were retrospectively reviewed. The median age was 7 years (range 9 months to 24 years). Thirty-five patients (53%) were treated for recurrent disease and 24 (36%) had documented metastatic disease. Twenty-nine patients (44%) received both EBRT and IOHDR. The IOHDR dose was prescribed to a depth of 0.5 cm from the surface of a multichannel tissue-equivalent applicator. The median prescription dose was 12 Gy (range, 4-15 Gy).

RESULTS

After a median follow-up of 12 months, the 2-year actuarial rates of local control and overall survival were 56% and 54%, respectively, with a median survival of 29 months. Post-operative EBRT significantly improved (p=0.002) 2-year local control (83% v. 29%). Perioperative complications occurred in 8 of 66 patients while late complications occurred in only 3. The actuarial 2-year late complication rate was 12%. Late events that occurred in or near the IOHDR treatment site included small bowel obstruction, broncho-esophageal fistula, and bone growth retardation.

CONCLUSIONS

IOHDR is emerging as an integral part of multimodality therapy for pediatric solid tumors as an adjunct to EBRT for local control. IOHDR alone may not be appropriate in the majority of patients. Subacute toxicities occurred rarely and may be related to the combination of extensive surgery, EBRT, and multi-agent chemotherapy in this population.

High-dose-rate intraoperative irradiation: current status and future directions

Intraoperative irradiation (IORT) refers to the delivery of a single high dose of radiation therapy at the time of surgery when the tumor bed can be precisely defined and adjacent normal tissue maximally protected. It can be effectively delivered using either electrons (IOERT) or photons produced from a high-dose-rate gamma emitting radioisotope (HDR-IORT) and has been explored primarily for locally advanced or recurrent tumors at high risk for local failure despite extensive resection and full dose external beam radiation. With coordinated multidisciplinary interaction, IORT can be integrated in a combined-modality setting without undue additional toxicity. The purpose of this review will be to summarize the growing HDR-IORT experience in the treatment of various cancers, to compare its efficacy and toxicity vis a vis the IOERT data, and to discuss future trials as well as new areas of potential application.

The American Brachytherapy Society recommendations for brachytherapy of soft tissue sarcomas

PURPOSE

This report presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with soft tissue sarcoma.

METHODS AND MATERIALS

Members of the ABS with expertise in soft tissue sarcoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report.

RESULTS

Brachytherapy used alone or in combination with external beam irradiation is an established means of safely providing adjuvant local treatment after resection for soft tissue sarcomas in adults and in children. Brachytherapy options include low dose rate techniques with iridium 192 or iodine 125, fractionated high dose rate brachytherapy, or intraoperative high dose rate therapy. Recommendations are made for patient selection, techniques, dose rates, and dosages. Complications and possible interventions to minimize their occurrence and severity are reviewed.

CONCLUSION

Brachytherapy represents an effective means of enhancing the therapeutic ratio, offering both biologic and dosimetric advantage in the treatment of patients with soft tissue sarcoma. The treatment approach used depends upon the institution, physician expertise, and the clinical situation. Guidelines are established for the use of brachytherapy in the treatment of soft tissue sarcomas in adults and in children. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose-reporting policies. These guidelines will be modified, as further clinical results become available.

Feasibility of intraoperative high-dose rate brachytherapy to boost low dose external beam radiation therapy to treat pediatric soft tissue sarcomas

PURPOSE

To determine if a single intraoperative high-dose-rate brachytherapy (IOHDR) dose can be used in conjunction with low dose external beam radiation therapy (EBRT) to treat soft tissue malignancies in children with reduced morbidity.

METHODS

From March 1992 to February 1995, six pediatric patients (4 boys, 2 girls; ages ranging from 4-13 years; median 10.5 years) were treated with IOHDR in conjunction with EBRT, chemotherapy, and radical surgery at nine sites not treatable by standard intraoperative electron beam radiation therapy techniques. The IOHDR dose was 10 Gy (at 7 sites with microscopic residual disease) or 12.5 Gy (at 2 sites with minimal gross residual disease) prescribed at 0.5 cm depth. The treatment volume varied from 9-96 cc (mean 30.3 cc). IOHDR was used in these patients because the tumor locations prevented positioning and insertion of conventional intraoperative electron beam applicators. The EBRT dose was limited to 27-30.6 Gy (median dose 27.4 Gy) postoperatively in all patients to minimize growth retardation or altered organ function. The median initial EBRT field size was 211 cm2 (range 25-483), with a median of two fields per patient (range 1-2).

RESULTS

After a median follow-up of 40 months (range 22-62 months), all the patients were alive, five of them without evidence of disease. The other patient, with stage IV undifferentiated synovial sarcoma developed regrowth of pulmonary metastases at 14 months and local failure at 34 months. Toxicity was seen in two patients. One patient developed recurrent urinary infections and ureteral stenosis after 6 months and required a left nephrectomy. Another developed mild to moderate loss of visual acuity and impaired orbital growth after 6 months.

CONCLUSIONS

Use of IOHDR in conjunction with low dose EBRT to obtain local control and long-term disease-free survival in pediatric soft tissue sarcomas is feasible with acceptable toxicity. Tumor beds not treatable with standard electron beam intraoperative radiation therapy could be satisfactorily encompassed with IOHDR.

Preliminary results of a phase I/II study of post-operative high-dose rate brachytherapy for advanced or recurrent pelvic tumours

Electron beam intraoperative radiation therapy (EB-IORT) and intraoperative low-dose rate brachytherapy (IOLB) seem able to improve the local control of advanced or recurrent pelvic tumours (ARPT). We report the usefulness, technical considerations and potential advantages of employing post-operative high-dose rate brachytherapy (POHB) as a treatment for ARPT. From February 1995 to February 1997, 14 patients underwent POHB for ARPT. The mean age was 58 years (range: 37-74). Six patients presented with recurrent rectal carcinoma, three with cervix carcinoma (one primary T3; two recurrences), two with bladder carcinoma (one primary T4; one recurrence), one with prostate carcinoma, one with recurrent pre-sacral lymphoma and one with undifferentiated carcinoma. At the time of resection, blind-end HDR catheters were implanted in a single plan in the tumour bed and stabilized by absorbable sutures. Eight days later, POHB delivered 20Gy in 5 fractions or 40Gy in 10 fractions for advanced and recurrent tumours, respectively. To decrease the incidence of late side-effects, a change was made after the tenth patient to deliver 2 Gy per fraction twice a day, with an interval of 6 h between each fraction. With a median follow-up of 8 months (range: 1-22), local control was achieved in all cases. Six patients developed metastatic disease. One patient presented a perineal wound dehiscence requiring surgery 2 months after POHB. POHB is feasible for patients with recurrent or advanced pelvic diseases, and appears more cost-effective than EB-IORT for dosimetric and radiobiological considerations. Compared with IOLB, POHB allows the total radioprotection of the medical staff, and, in the context of cost reduction, a reduction of the overall time of hospitalization.