Intraoperative High Dose Rate Research Articles

Intraoperative high dose rate brachytherapy during breast-conserving surgery: A prospective pilot study.

To evaluate feasibility, quality of life, toxicity, and cosmetic outcome for intraoperative breast cancer brachytherapy after breast-conserving surgery using high dose rate brachytherapy. Fifty-two consecutive women, ⩾50 years old, diagnosed with a unifocal non-lobular breast cancer ⩽3 cm, N0, underwent breast-conserving surgery and sentinel node biopsy. Twenty-five women received intraoperative brachytherapy pre-pathology at primary surgery and the others post-pathology, during a second procedure. An applicator, connected to a high dose rate afterloader, was used. Two of the women were excluded due to metastases found per-operatively at a frozen section from the sentinel node. Quality of life was evaluated using two validated health questionnaires. Treatment toxicity was documented according to the LENT-SOMA scale by two oncologists. The cosmetic result was evaluated using the validated freely available software BCCT.core 2.0. The clinical procedure worked out well logistically. Seven women received supplementary external radiotherapy due to insufficient margins and, in one case, poor adaptation of the breast parenchyma to the applicator. No serious adverse effects from irradiation were registered. The results from the health questionnaires showed no major differences compared with reference groups from the Swedish population. Only two women were registered as having a "poor" cosmetic result while a majority of the women had a "good" outcome. This pilot study shows that intraoperative brachytherapy is a feasible procedure and encourages further trials evaluating its role in treatment of early breast cancer.

Comparison of Lung Dose in Breast Cancer Treated with Intraoperative High Dose Rate Brachytherapy versus Adjuvant External Beam Radiation Therapy

Comparison of Lung Dose in Breast Cancer Treated with Intraoperative High Dose Rate Brachytherapy versus Adjuvant External Beam Radiation Therapy

Time-Driven Activity-Based Cost Analysis of CT-Guided Intraoperative High-Dose Rate Brachytherapy Versus Whole Breast Irradiation in the Treatment of Early Stage Breast Cancer

To evaluate the health care delivery cost of single fraction CT-guided intraoperative high-dose rate brachytherapy (HDR-IORT) in early stage breast cancer using time-driven activity-based costing (TDABC). Process maps were created for each step of the radiation treatment process at our institution for early stage breast cancer. The capacity cost from consultation to completion of radiation was calculated for personnel, equipment, and consumable resource. Personnel costs were calculated using individual personnel time and salary data. Equipment costs were calculated to include cost of CT-simulation, treatment planning software, and treatment machine time. Consumable costs were limited to resources specific to the individual radiation treatment (e.g. multi-lumen balloon) of each patient and did not include diagnostic, surgical, or anesthesia costs associated with lumpectomy alone as patients treated with whole breast irradiation (WBI) incurred similar costs. Patients are treated with HDR-IORT on an ongoing prospective trial. The procedure includes lumpectomy and placement of a multi-lumen balloon applicator by the breast surgeon. Intraoperative CT on-rails is utilized for image confirmation of catheter placement, treatment planning and delivery of 12.5 Gy to 1 cm from the balloon surface. In comparison, whole breast irradiation (WBI) alone consisted of 42.56 Gy in 16 fractions, with consideration of a 4 fraction boost. The total health care cost to deliver HDR-IORT for a patient was $4,875. The total cost to deliver WBI alone was $2,832, with an additional $363 for a 4 fraction boost. Radiation oncology personnel accounted for $1,909 (39%) and $1,658 (59%) of the total IORT and WBI cost, respectively. Surgical attending physician time required an additional 30 minutes to allow for balloon placement and image-guided confirmation in the brachytherapy suite. During HDR-IORT, the anesthesia team spent an additional 315 minutes (accounting for multiple team members). Radiation oncology attending time was 16% less for HDR-IORT compared to WBI, 91 minutes versus 108 minutes respectively. Equipment cost was $216 (4%) and $1,174 (41%) for the total cost of HDR-IORT and WBI, respectively. The cost of the multi-lumen balloon applicator ($2,750 per patient) represented 56% of the total IORT cost. TDABC analysis demonstrates a higher cost of delivery for treatment with HDR-IORT compared to WBI, largely due to increased consumable costs. Our calculated total delivery cost ($4,875), which exceeds the current payment rates for other forms of breast IORT, should be considered for reimbursement decisions. These findings exemplify that a streamlined process and dedicated team can result in efficient delivery of HDR-IORT.

PRELIMINARY TESTS OF LOCAL HYPERTHERMIA BASED ON INDUCTIVELY HEATED TUMOR BED IMPLANT

Hyperthermia, i.e. tissue heating to a temperature of 39-45°C, is considered to be a very promising technique to increase the sensitivity of tumor cells to ionizing radiation and chemical preparations. At the present time, there are numerous methods for producing hyperthermia with the optimum method dependent on the required volume, depth, and site of heating. This paper presents the results of preliminary theoretical and in vivo confirmation studies of the feasibility of intraoperative local hyperthermia via induction heating of ferromagnetic material within a tumor bed implant that fills a resected tumor cavity. The implant is made during the surgical removal of tumor by mechanically filling the tumor bed with a self-polymerizing silicone paste in which very fine electroconductive ferromagnetic particles are uniformly distributed. Therefore, the implant can accommodate unique characteristics of each patient’s tumor bed. For the laboratory experiments, a prototype induction heating system was used to produce an alternating magnetic field with a frequency of about 100 kHz and a maximum intensity up to 3 kA/m inside an induction coil of inner diameter 35 cm. Experiments were conducted to heat a 2.5 cm diameter spherical implant both in open air and inside the thigh of a living rabbit. The results in both cases are in good agreement with our theoretical estimations. It was established that the temperature gradient near the implant surface decreases with increasing implant size, and for typical size tumor bed implants produces effective hyperthermia to a distance of more than 5 mm from the implant surface. This result provides hope for a decrease in relapse after treatment of malignant tumors using our combination heat plus intraoperative high dose rate local radiotherapy approach. Moreover, the externally coupled implant heating can be combined with local chemotherapy by applying a self-resorbable polymer film containing antineoplastic agents to the surface of the implant.

Intraoperative High Dose Rate Brachytherapy Can Be Used to Salvage Patients with Previously lrradiated Head and Neck Recurrences

Purpose: To develop a novel technique, intraoperative high-dose rate brachytherapy (IOHDR), in the treatment of previously irradiated head and neck cancers located at anatomical sites inaccessible to intraoperative electron beam radiotherapy (IOERT). 
 
 Methods: Between October 1992 and June 1997, seven patients (median age=65 years; range=52 to 71 years) with previously irradiated head and neck recurrences at anatomical sites inaccessible to IOERT in the base of skull were treated with IOHDR after maximal resection for microscopic residual disease. Treatment volume ranged from 6 cc to 24 cc. Six patients received 15 By of IOHDR at 0.5 cm; one received 10 By using custom-made surface foam applicators. 
 
 Results: The median follow-up was 59 months (range 33 to 67 months). It was technically feasible to deliver IOHDR in all seven patients at sites that were inaccessible to IOERT. The morbidity (observed in two patients) was acceptable and generally surgically related. Four of seven patients (57%) were locally controlled at IOHDR site. Two failed regionally, outside the IOHDR treated sites. The disease-free survival ranged from 3 to 30 months (median 9 months) with two patients still alive, disease-free at 28 and 30 months. 
 
 Conclusions: IOHDR can be used, with limited toxicity, to treat previously irradiated head and neck cancers at sites inaccessible to IOERT. We are currently evaluating the addition of limited EBRT dose to improve the local control of these poor prognosis recurrent tumors.

Automated construction of an intraoperative high-dose-rate treatment plan library for the Varian brachytherapy treatment planning system

PurposeThe ability to create treatment plans for intraoperative high-dose-rate (IOHDR) brachytherapy is limited by lack of imaging and time constraints. An automated method for creation of a library of high-dose-rate brachytherapy plans that can be used with standard planar applicators in the intraoperative setting is highly desirable. Methods and MaterialsNonnegative least squares algebraic methods were used to identify dwell time values for flat, rectangular planar applicators. The planar applicators ranged in length and width from 2 cm to 25 cm. Plans were optimized to deliver an absorbed dose of 10 Gy to three different depths from the patient surface: 0 cm, 0.5 cm, and 1.0 cm. Software was written to calculate the optimized dwell times and insert dwell times and positions into a .XML plan template that can be imported into the Varian brachytherapy treatment planning system. The user may import the .XML template into the treatment planning system in the intraoperative setting to match the patient applicator size and prescribed treatment depth. ResultsA total of 1587 library plans were created for IOHDR brachytherapy. Median plan generation time was approximately 1 minute per plan. Plan dose was typically 100% ± 1% (mean, standard deviation) of the prescribed dose over the entire length and width of the applicator. Plan uniformity was best for prescription depths of 0 cm and 0.5 cm from the patient surface. ConclusionsAn IOHDR plan library may be created using automated methods. Thousands of plan templates may be optimized and prepared in a few hours to accommodate different applicator sizes and treatment depths and reduce treatment planning time. The automated method also enforces dwell time symmetry for symmetrical applicator geometries, which simplifies quality assurance.

Intraoperative high-dose rate of radioactive phosphorus 32 brachytherapy for diffuse recalcitrant conjunctival neoplasms: a retrospective case series and report of toxicity.

Adjunct treatments for conjunctival malignancies are needed when standard therapy provides limited benefits or fails. To describe the results of patients with diffuse conjunctival neoplasms treated with radioactive phosphorus 32 (32P)-impregnated flexible film. This retrospective case series between January 1, 2010, and January 1, 2013, was conducted at Memorial Sloan-Kettering Cancer Center, a tertiary referral center. The study was conducted on 7 eyes of 6 patients treated for diffuse conjunctival squamous cell carcinoma, sebaceous carcinoma, or lymphoma that had recurrent or residual disease after primary treatment. Patients underwent mapping biopsies and detailed conjunctival drawings to delineate the pathologic extent of the disease. The brachytherapy film used for treatment was the RIC Conformal Source Model 100 (RIC-100, RI Consultants). The RIC-100 is a flexible, thin (approximately 0.5-mm) film made of a polymer chemically bound to 32P. The radioactive 32P film was placed intraoperatively, allowed to stay in place until the prescription dose was reached, and then removed. The median dose at the prescription point (1 mm from the surface of the film) was 15 Gy (range, 5-17 Gy). Patients were tested for best-corrected visual acuity, recurrence-free survival, and adverse events scored by using the Adult Comorbidity Evaluation-27 scale. Between 2010 and 2013, 7 eyes of 6 patients were treated. The median age of patients was 70 years. All patients had a recurrent or persistent neoplasm. Four patients with squamous cell carcinoma, 1 with sebaceous carcinoma, and 1 with metachronous bilateral lymphomas were treated. The median treatment time was 19 minutes (range, 10-52 minutes). The median follow-up was 24.9 months (range, 3.1-38.2 months). Recurrence-free survival 24 months after brachytherapy was 75% (95% CI, 19-89.1). Two moderate adverse events and 1 severe adverse event occurred. Visual acuity was stable or improved in 5 of the 7 eyes (ie, better than 20/70 in the 5 patients who retained their treated eye). Our results show the use of an intraoperative high-dose rate of 32P brachytherapy in selected cases of recalcitrant diffuse conjunctival neoplasms. This technique offers a novel adjunct in the treatment of these cancers. Further follow-up and study are warranted.

Evaluation of time, attendance of medical staff, and resources during interstitial brachytherapy for prostate cancer

The German Society of Radiation Oncology initiated a multicenter trial to evaluate core processes and subprocesses of radiotherapy by prospective evaluation of all important procedures in the most frequent malignancies treated by radiation therapy. The aim of this analysis was to assess the required resources for interstitial high-dose-rate (HDR) and low-dose-rate (LDR) prostate brachytherapy (BRT) based on actual time measurements regarding allocation of personnel and room occupation needed for specific procedures. Two radiotherapy centers (community hospital of Offenbach am Main and community hospital of Eschweiler) participated in this prospective study. Working time of the different occupational groups and room occupancies for the workflow of prostate BRT were recorded and methodically assessed during a 3-month period. For HDR and LDR BRT, a total of 560 and 92 measurements, respectively, were documented. The time needed for treatment preplanning was median 24min for HDR (n = 112 measurements) and 6min for LDR BRT (n = 21). Catheter implantation with intraoperative HDR real-time planning (n = 112), postimplantation HDR treatment planning (n = 112), and remotely controlled HDR afterloading irradiation (n = 112) required median 25, 39, and 50min, respectively. For LDR real-time planning (n = 39) and LDR treatment postplanning (n = 32), the assessed median duration was 91 and 11min, respectively. Room occupancy and overall mean medical staff times were 194 and 910min respectively, for HDR, and 113 and 371min, respectively, for LDR BRT. In this prospective analysis, the resource requirements for the application of HDR and LDR BRT of prostate cancer were assessed methodically and are presented for first time.

Intraoperative high dose rate brachytherapy (HDR-IORT) in locally advanced rectal cancer

Intraoperative high dose rate brachytherapy (HDR-IORT) in locally advanced rectal cancer

Dose optimization of intra-operative high dose rate interstitial brachytherapy implants for soft tissue sarcoma

A three dimensional (3D) image-based dosimetric study to quantitatively compare geometric vs. dose-point optimization in combination with graphical optimization for interstitial brachytherapy of soft tissue sarcoma (STS). Fifteen consecutive STS patients, treated with intra-operative, interstitial Brachytherapy, were enrolled in this dosimetric study. Treatment plans were generated using dose points situated at the "central plane between the catheters", "between the catheters throughout the implanted volume", at "distances perpendicular to the implant axis" and "on the surface of the target volume" Geometrically optimized plans had dose points defined between the catheters, while dose-point optimized plans had dose points defined at a plane perpendicular to the implant axis and on the target surface. Each plan was graphically optimized and compared using dose volume indices. Target coverage was suboptimal with coverage index (CI = 0.67) when dose points were defined at the central plane while it was superior when the dose points were defined at the target surface (CI=0.93). The coverage of graphically optimized plans (GrO) was similar to non-GrO with dose points defined on surface or perpendicular to the implant axis. A similar pattern was noticed with conformity index (0.61 vs. 0.82). GrO were more conformal and less homogeneous compared to non-GrO. Sum index was superior for dose points defined on the surface of the target and relatively inferior for plans with dose points at other locations (1.35 vs. 1.27). Optimization with dose points defined away from the implant plane and on target results in superior target coverage with optimal values of other indices. GrO offer better target coverage for implants with non-uniform geometry and target volume.

Intraoperative Electron Irradiation for Locally Recurrent Colorectal Cancer

Intraoperative electron radiation therapy (IOERT) has been used at Mayo Clinic as a component of therapy for patients (pts) with locally advanced recurrent colorectal cancer since 1981. This review was performed to evaluate survival, relapse patterns, and prognostic factors in patients with colorectal cancer relapse treated with curative intent. Between April 1981 and February 2008, 607 pts with locally recurrent colorectal cancer received IOERT as a component of therapy. The population includes 238 females and 369 males with a median age of 62 years (range, 21-87). The median interval from primary diagnosis to recurrence was 27 months. External beam radiotherapy (EBRT) had been previously delivered to 271 pts (45%) and chemotherapy (CT) to 364 (60%). Maximum resection with IOERT was preceded or followed by EBRT (median dose 4550 cGy, range 500-6500 cGy) in 583 pts (96%). CT was delivered concomitantly with EBRT in 492 pts (81%) while maintenance CT was administered in 107 pts (18%). Surgical resection at time of IOERT was classified as R2 (gross residual) in 156 (26%), R1 (microscopically positive margins) in 224 (37%), and R0 (negative margins) in 227 (37%). IOERT was delivered with 6-20 MeV electrons in doses ranging from 750-3000 cGy (median 1500 cGy). Two patients were treated with intraoperative high dose rate brachytherapy. Endpoints include survival (OS), local relapse (LF), central relapse within the IOERT field (CF), and distant metastases (DM). All pts have been followed until death or a median of 44 months for survivors. OS at 5 years was 30%, LF was observed in 38%, CF in 19%, and DM in 62%. Resection margin status was predictive for OS, LF, and DM. 5-yr OS was 46%, 27%, and 16% for R0, R1, and R2 resection, respectively (p < 0.0001). LF at 5 years was observed in 26%, 44%, and 51% (p = 0.003), CF in 11%, 24%, and 24% (p = 0.03), and DM in 53%, 62%, and 73% (p < 0.0001) for R0, R1, and R2 resection, respectively. On multivariate analysis, R0 resection, no prior CT, use of systemic maintenance CT, and IOERT after 1996 predicted for OS, and 59% of pts with 3 or more favorable factors were 5-yr survivors. R1-2 resection, prior EBRT, and IOERT before 1997 predicted for LF, and prior CT, R1-2 resection, and IOERT before1997 predicted for DM. Toxicity grade ≥3 partially attributable to IOERT was observed in 66 pts (11%). Neuropathy was observed in 133 pts (22%) including 37 (6%) with grade 1, 64 (11%) with grade 2, and 37 (6%) with grade 3 neuropathy. Long term survival and disease control is achievable in pts with locally recurrent colorectal cancer. Prognosis is best in less heavily pre-treated pts who receive systemic CT following an R0 resection and has improved in the past decade. Continued evaluation of curative intent combined modality therapy including IOERT is warranted in this high risk population.

Impact of Surface Curvature on Dose Delivery in Intraoperative High-Dose-Rate Brachytherapy

In intraoperative high-dose-rate (IOHDR) brachytherapy, a 2-dimensional (2D) geometry is typically used for treatment planning. The assumption of planar geometry may cause serious errors in dose delivery for target surfaces that are, in reality, curved. A study to evaluate the magnitude of these errors in clinical practice was undertaken. Cylindrical phantoms with 6 radii (range: 1.35–12.5 cm) were used to simulate curved treatment geometries. Treatment plans were developed for various planar geometries and were delivered to the cylindrical phantoms using catheters inserted into Freiburg applicators of varying dimension. Dose distributions were measured using radiographic film. In comparison to the treatment plan (for a planar geometry), the doses delivered to prescription points were higher on the concave side of the geometry, up to 15% for the phantom with the smallest radius. On the convex side of the applicator, delivered doses were up to 10% lower for small treated areas (≤ 5 catheters) but, interestingly, the dose error was negligible for large treated areas (>5 catheters). Our measurements have shown inaccuracy in dose delivery when the original planar treatment plan is delivered with a curved applicator. Dose delivery errors arising from the use of planar treatment plans with curved applicators may be significant.

SU-FF-T-302: Monte Carlo Dose Verification and Application of Complex IOHDR Geometries

Purpose: Dose computation algorithm may lead to serious dose errors in intra-operative high dose rate (IOHDR) brachytherapy due to the lack of scatter from one side of the applicator and/or complex geometries of treated areas. Our group has reported the inaccuracy in clinical dose delivery for general cases through several experimental approaches. However, more accurate Monte Carlo calculations are needed to quantify dose errors in IOHDR delivered with more complex geometries and scattering environment. Method and Materials: Dose calculations were done using the EGSnrc Monte Carlo code system and the setup geometry including source structure was designed with the geometry package using EGSnrc C++ library class. User-code was developed from an existing EGSnrc user-code CAVRZnrc. To benchmark the code, a few steps were carried out to ensure that the accuracy of the cavity dose for a given simple geometry option and the ratio of cavity doses with the varying distance from the source to the center of cavity for different geometries. Based on accurate results of benchmarking geometries, test input files were developed to verify the accuracy of delivered doses for the measured known results that we had already reported the with linear array ion-chamber. Results: For the 1.0 cm prescription distance, Monte Carlo results showed about 14 % higher for added tissue equivalent materials of 15 cm. Also, calculated doses were 1.5 to 2 % higher than measured doses for added materials of above 5 cm. However, Monte Carlo showed an excellent agreement for 1.5 cm prescription distance and simulated uncertainties of 0.01 % to 0.1 %. Conclusion: Computed doses obtained using EGSnrc system for known geometries validate the results of ion-chamber measurement. This Monte Carlo calculation will improve the approach of dose calculations for complex geometries and the efficiency of dose delivery in clinical cases.

Retrospective analysis of dose delivery in intra-operative high dose rate brachytherapy

Background. This study was performed to quantify the inaccuracy in clinical dose delivery due to the incomplete scatter conditions inherent in intra-operative high dose rate (IOHDR) brachytherapy. Methods. Treatment plans of 10 patients previously treated in our facility, which had irregular shapes of treated areas, were used. Treatment geometries reflecting each clinical case were simulated using a phantom assembly with no added build-up on top of the applicator. The treatment planning geometry (full scatter surrounding the applicator) was subsequently simulated for each case by adding bolus on top of the applicator. Results. For geometries representing the clinical IOHDR incomplete scatter environment, measured doses at the 5 mm and 10 mm prescription depths were lower than the corresponding prescribed doses by about 7.7% and 11.1%, respectively. Also, for the two prescription methods, an analysis of the measured dose distributions and their corresponding treatment plans showed average decreases of 1.2 mm and 2.2 mm in depth of prescription dose, respectively. Conclusions. Dosimetric calculations with the assumption of an infinite scatter environment around the applicator and target volume have shown to result in dose delivery errors that significantly decrease the prescription depth for IOHDR treatment.

SU‐FF‐T‐170: Dose Delivery to Curved Structures in Intra‐Operative High Dose Rate (IOHDR) Brachytherapy

Purpose: To investigate the magnitude of overdosage / underdosage for curved surfaces in intra‐operative high dose rate (IOHDR) brachytherapy when the original treatment plan assumed a planar geometry. Method and Materials: The archived IOHDR brachytherapy treatment plans of 5 cases were used in this study. Plans of 3 patients treated in our facility were chosen for the different treatment surface areas and two plans with square fields were developed to compare with irregular shape of clinical cases. Phantoms with four various radii (5 cm to 13.5 cm) were used to simulate the treatment planning geometries which were calculated in 2‐dimensional plans. EDR2 radiographic film dosimetry was used to evaluate the dose distribution for each case. Each film was digitized with 0.17 mm resolution using a film dosimetry system and converted to dose. Results: A 2‐D planar implant was designed to deliver a dose of 200 cGy to the prescription depth. This implant applicator was then wrapped around curved phantoms of different radii and the identical treatment was delivered for each curved structure. However, the actual doses delivered to the prescription points were about 9 % (5.5 % for small treatment area − 3 catheter × 4 cm2) higher for the convex with respect to the prescription point with 5 cm radius at 1 cm prescription distance. The actual delivered dose was increased linearly proportional to decreasing of the radius of convex. Conclusion: In IOHDR clinical cases, 2‐dimensional planning geometry is typically used without considering the curved shape of the patient's structure. Our measurements have shown an overdosage when the original planar treatment plan was delivered in a convex setting resulting in an increase in the prescription depth which may be clinically relevant.

TU‐EE‐A1‐01: Accuracy of Clinical Dose Delivery in IOHDR Brachytherapy

Purpose: To investigate the accuracy of clinical dose delivery in intra‐operative high dose rate (IOHDR) brachytherapy. Method and Materials: The IOHDR brachytherapy treatments of 10 patients recently treated at our facility were reconstructed. Treatment geometries reflecting each clinical scenario were simulated by a phantom assembly with no added buildup on top of the applicator. EDR2 radiographic film placed at the prescription depth recorded dose distributions for each clinical case. The treatment planning geometry (full scatter surrounding the applicator) was subsequently simulated for each case by adding bolus on top of the applicator and radiographic film was again exposed at the treatment depth. After careful determination of the film's H&amp;D curve, absolute dose distributions in the plane of the prescription depth were evaluated for both scatter environments in each clinical case. Results: For the geometries simulating the treatment planning conditions of full scatter, the average dose measured at the treatment depths was within 2% of the prescription and dose distributions were in excellent agreement with the respective treatment plan. However, for the geometry simulating treatment conditions (no added scattering material above the applicator), the dose at the prescription depth was on average 11% lower (range 8–14%) than prescribed. An analysis of the delivered dose distributions and treatment plans shows a resulting average decrease of 2 mm (range 1.2–2.4 mm) in prescription depth. Conclusion: Dosimetry calculations for IOHDR brachytherapy are typically done with treatment planning systems with dose calculation algorithms that assume an infinite scatter environment around the applicator and target volume. We have shown that this assumption leads to dose delivery errors which result in significant foreshortening of the prescription depth. It may be clinically relevant to correct for these errors by augmenting the scatter environment or, preferably, by appropriately modifying the prescription dose entered into the treatment planning system.

A Systematic Overview of Radiation Therapy Effects in Soft Tissue Sarcomas

A systematic review of radiation therapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation of the scientific literature are described separately (Acta Oncol 2003; 42: 357-365). This synthesis of the literature on radiation therapy for soft tissue sarcomas (STS) is based on data from five randomized trials. Moreover, data from 6 prospective studies, 25 retrospective studies and 3 other articles were used. In total, 39 scientific articles are included, involving 4 579 patients. The results were compared with those of a similar overview from 1996 which included 3 344 patients. The conclusions reached can be summarized as follows: <list id="l1" type="5"> <item>The well-established prognostic factors for tumour-related death from STS--histological grade, tumour size and age--are well documented.</item><item>The importance of superficial versus deep site as well as the anatomic site is also reaffirmed to some extent.</item><item>There is strong evidence that adjuvant radiotherapy improves the local control rate in combination with conservative surgery in the treatment of STS of extremities and trunk in patients with negative, marginal or minimal microscopic positive surgical margins. A local control rate of 90% has been achieved.</item><item>Improvement is obtained with radiotherapy added in the case of intralesional surgery, but the local control rate is somewhat lower. More studies are needed on this issue.</item><item>For STS in other anatomic sites, retroperitoneum, head and neck, breast and uterus, there is only weak indication of a benefit for the local control rate, with the use of adjuvant radiotherapy.</item><item>There is still insufficient data to establish that preoperative radiotherapy is favourable compared to postoperative radiotherapy for local control in patients presenting primarily with large tumours. One small study has shown a possible survival benefit for preoperative radiotherapy.</item><item>There is fairly good evidence to suggest that the preoperative setting results in more wound complications.</item><item>There is no randomized study comparing external beam radiotherapy and brachytherapy. The data suggest that external beam radiotherapy and low dose rate brachytherapy result in comparable local control for high-grade tumours.</item><item>Some patients with low-grade soft tissue sarcomas benefit from external beam radiotherapy in terms of local control.</item><item>Brachytherapy with low dose rate for low-grade tumours seems to be of no benefit, but data are sparse.</item><item>The available data are inconclusive concerning the effect of intraoperative high dose rate radiotherapy for retroperitoneal STS. Further studies are needed.</item><item>Neutron radiotherapy might be beneficial for patients with low- and intermediate-grade tumours considered inoperable and for those operated with intralesional margins. More severe side effects for neutrons have been registered.</item><item>In two small studies investigating hyperfractionation schedules there was no indication of improvements compared to daily fractions of 2 Gy. Further studies should be encouraged.</item><item>One small study using preoperative limb perfusion with TNFα melphalan and ±interferon γ combined with postoperative radiotherapy in the case of marginal or positive surgical margin has shown excellent local control without enhanced morbidity.</item></list>

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.

454 poster Intraoperative High Dose Rate (HDR) quality assurance in an occupied

454 poster Intraoperative High Dose Rate (HDR) quality assurance in an occupied

28 Intraoperative high dose rate brachytherapy for head and neck tumors

28 Intraoperative high dose rate brachytherapy for head and neck tumors