A simple method of obtaining equivalent doses for use in HDR brachytherapy

Acute genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

PURPOSE

Several investigations have revealed that the alpha/beta ratio for prostate cancer is atypically low, and that hypofractionation or high-dose-rate (HDR) brachytherapy regimens using appropriate radiation doses may be expected to yield tumor control and late sequelae rates that are better or at least as favorable as those achieved with conventional radiation therapy. In this setting, we attempted treating localized prostate cancer patients with HDR brachytherapy combined with hypofractionated external beam radiation therapy (EBRT). The purpose of this study was to evaluate the feasibility of using this approach, with special emphasis on the relationship between the severity of acute genitourinary (GU) toxicity and the urethral dose calculated from the dose-volume histogram (DVH) of HDR brachytherapy.

METHODS AND MATERIALS

Between September 2000 and December 2003, 70 patients with localized prostate cancer were treated by iridium-192 HDR brachytherapy combined with hypofractionated EBRT at the Gunma University Hospital. Hypofractionated EBRT was administered in fraction doses of 3 Gy, three times per week; a total dose of 51 Gy was delivered to the prostate gland and the seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography (TRUS)-guided HDR brachytherapy. The fraction size and the number of fractions in HDR brachytherapy were prospectively changed, whereas the total radiation dose for EBRT was fixed at 51 Gy. The fractionation in HDR brachytherapy was as follows: 5 Gy x 5, 7 Gy x 3, 9 Gy x 2, administered twice per day, although the biologic effective dose (BED) for HDR brachytherapy combined with EBRT, assuming that the alpha/beta ratio is 3, was almost equal to 138 in each fractionation group. The planning target volume was defined as the prostate gland with 5-mm margin all around, and the planning was conducted based on computed tomography images. The number of patients in each fractionation group was as follows: 13 in the 5-Gy group; 19 in the 7-Gy group, and 38 in the 9-Gy group. The tumor stage was T1 in 10 patients, T2 in 36 patients, and T3 in 24 patients. The Gleason score was 2-6 in 11 patients, 7 in 34 patients, and 8-10 in 25 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 14 months (range 3-42 months). The toxicities were graded based on the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity criteria.

RESULTS

The main symptoms of acute GU toxicity were dysuria and increase in urinary frequency or nocturia. The grade distribution of acute GU toxicity in the patients was as follows: Grade 0-1, 39 patients (56%), and Grade 2-4, 31 patients (44%). One patient who developed acute urinary obstruction was classified as having Grade 4 toxicity. Comparison of the distribution of the grade of acute GU toxicity among the different fractionation groups revealed no statistically significant differences among the groups. The urethral dose in HDR brachytherapy was evaluated using the following DVH parameters: V30 (percentage of the urethral volume receiving 30% of the prescribed radiation dose), V80, V90, V100, V110, V120, V130, and V150. The V30-110 values in the patients with Grade 2-4 acute GU toxicity were significantly higher than those in patients with Grade 0-1 toxicity. On the other hand, there were no significant differences in the V120-150 values between patients with Grade 0-1 and Grade 2-4 toxicity. Regarding the influence of the number of needles implanted for the radiation therapy, patients with 11 needles or less showed a significantly higher incidence of Grade 2-4 acute GU toxicity compared with those with 12 needles or more (p < 0.05).

CONCLUSIONS

It was concluded that HDR brachytherapy combined with hypofractionated EBRT is feasible for localized prostate cancer when considered from the viewpoint of acute toxicity. Increase in the fraction dose or reduction in the number of fractions in HDR brachytherapy did not affect the severity of acute GU toxicity, and the volume of urethra receiving an equal or lower radiation dose than the prescribed dose was more closely associated with the grade severity of acute GU toxicity than that receiving a higher than the prescribed dose.

The emerging role of high-dose-rate brachytherapy for prostate cancer

By placing radioactive sources directly into the cancer, brachytherapy allows delivery of a highly conformal radiation dose to the prostate. Permanent seed brachytherapy is most commonly used for low-risk cancer, whereas high-dose-rate (HDR) brachytherapy is combined with external-beam radiotherapy to treat higher risk disease. The high rate of dose delivery and the large fraction size may be a radiobiological advantage for tumours with high sensitivity to radiation fraction size. The ability to optimise dose delivery allows for exquisite shaping of dose around the prostate and sparing of normal tissues. HDR brachytherapy is most commonly delivered in two or more fractions of 810 Gy combined with 40-50 Gy external beam. Published studies are almost entirely limited to single-institution case series. Most of the patients treated have relatively unfavourable localised disease, with a reported disease-free survival of 68-93%, and a local control rate of over 90%. Treatment is well tolerated, with urethral stricture the most common late effect (risk around 8%). Early results using HDR monotherapy in low-risk disease seem promising. Patients most likely to benefit from a combined HDR/external-beam approach have bulky local disease (stage T2b-T3) or intermediate to high-grade cancers. Prospective multicentre studies of HDR brachytherapy have begun in this patient group in Canada and the USA, which hopefully will allow future comparisons with high-dose conformal external-beam techniques.

Long-term results of high-dose rate intracavitary brachytherapy for squamous cell carcinoma of the uterine cervix

BACKGROUND

The authors performed a long-term follow-up study to evaluate the efficacy and late toxicity of high-dose rate intracavitary brachytherapy (HDR-ICBT) for cervical carcinoma.

METHODS

From 1968 to 1986, 1148 patients with Stage IB to IVB squamous cell carcinoma of the cervix (staging was performed according to the International Federation of Gynecology and Obstetrics) were treated with a combination of external beam radiotherapy (EBRT) and HDR-ICBT. For patients with early-stage disease, 20 gray (Gy) of EBRT was delivered to the whole pelvis, followed by 24 Gy/4 fractions of HDR-ICBT and 30 Gy of central-shielding EBRT. For patients with advanced-stage disease, 20-40 Gy of whole pelvic EBRT was administered, followed by 24 Gy/4 fractions of ICBT and 30-10 Gy of central-shielding EBRT. The overall treatment time was approximately 6 weeks. Among survivors, the follow-up rate was 98% and the median follow-up duration was 22 years.

RESULTS

The 10-year pelvic tumor control rates were 93% for patients with Stage IB disease, 82% for patients with Stage II disease, and 75% for patients with Stage III disease. The 10-year overall and cause-specific survival rates were 74% and 89% for patients with Stage IB disease, 52% and 74% for patients with Stage II disease, and 42% and 59% for patients with Stage III disease, respectively. The 10-year actuarial rates of major complications were 4.4% in the rectosigmoid colon, 0.9% in the bladder, and 3.3% in the small intestines.

CONCLUSIONS

The results of the current study suggest that the combination of EBRT and HDR-ICBT according to the authors' protocol provided outcomes that were comparable to those of the conventional low-dose rate brachytherapy with acceptable rates of late complications in the treatment of cervical carcinoma.

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.

Chest wall dose in MammoSite™ breast brachytherapy: Radiobiologic estimations of late complication risk based on dose–volume considerations

PURPOSE

To estimate the risk of late effects in women treated with MammoSite brachytherapy (MBT), the balloon catheters of which were placed near the ribs.

METHODS AND MATERIALS

Upon reviewing 93 plans, 16 patients (17%) treated with MBT were considered to have received a high chest wall dose (>or=120% isodose line in contact with a rib). A dose-volume histogram was generated for this rib, and its distance from the MBT balloon measured. Using the linear quadratic equation, the equivalent dose, delivered in 10 fractions, to the dose that causes a 5% and 50% risk of rib late effects at 5 years using 2Gy per fraction, was calculated to be 37 and 44Gy, respectively. The rib volume receiving greater than or equal to these doses (V37 and V44) was correlated to the balloon-to-rib distance. Chest wall signs, symptoms, and radiologic findings for all 16 patients were recorded.

RESULTS

The median balloon-to-rib distance was 4.8mm. The median values of V37 and V44 were 13.5% and 3.3%, respectively. All patients with a V37>or=15% and V44>or=5% had a minimum balloon-to-rib distance of <5mm. Two patients reported treatment-related chest wall tenderness (both had balloons placed <5mm from the chest wall), but neither presented with radiologic complications.

CONCLUSIONS

Sixteen patients considered to receive relatively high chest wall doses had less than one-third of their primary rib volume being exposed to the estimated TD 5/5 and TD 50/5 doses. Therefore, we estimate the risk of late effects in women treated with MBT, the balloon catheters of which placed near the ribs were negligible, and believe that MBT remains a safe and effective treatment for selected patients with early stage breast cancer.

Intraoperative single fraction high-dose-rate brachytherapy for head and neck cancers

PURPOSE

To report on the use of single fraction high-dose-rate brachytherapy in delivering localized intraoperative radiation therapy to sites in the head and neck region inaccessible to intraoperative electron beam radiotherapy (IOERT).

METHODS AND MATERIALS

After maximal surgical resection, 7.5-20 Gy intraoperative high-dose-rate brachytherapy (IOHDR) was delivered to 65 patients using custom-made surface applicators.

RESULTS

The 1-, 3-, and 5-year local control rates for the entire group were 77%, 69%, and 59%, respectively. The 1-, 3-, and 5-year overall survival rates were 83%, 63%, and 42%, respectively, with a median overall survival of 50 months. There were no major intraoperative or postoperative complications.

CONCLUSIONS

IOHDR can be used to treat selected locally advanced head and neck tumors arising at sites inaccessible to IOERT or at institutions not using IOERT. A prospective multi-institutional study with a larger number of patients treated with IOHDR is needed to firmly establish the efficacy of IOHDR in this population group.

Feasibility and preliminary outcome of salvage combined HDR brachytherapy and external beam radiotherapy (EBRT) for local recurrences after radical prostatectomy

PURPOSE

Feasibility of combined fractionated intensity modulated brachytherapy (IMBT) and external beam radiotherapy (EBRT) as well as the effect of local dose escalation was investigated in a non-randomized retrospective observation trial for histologically-proven macroscopic local recurrences of prostate cancer after radical prostatectomy.

METHODS AND MATERIALS

Thirty-five patients with transrectal ultrasound (TRUS) detectable tumors were treated. Applied dose per IMBT fraction was 15 Gy, prescribed on the target (TRUS visible tumor) surface. For the first 21 patients, two fractions of IMBT were delivered in 2 weeks interval, complementary to 30 Gy EBRT to the small pelvis. Further, as second step of dose escalation, 14 patients were treated with 2 x 15 Gy IMBT combined with 40 Gy EBRT. The total treatment time was 4 and 5 weeks, respectively.

RESULTS

PSA was decreased in 34 out of 35 patients post-therapeutically. After a mean follow-up of 27 months, 32 out of 35 patients are alive. However, in 67% of the patients, we observed postimplant PSA elevation with or without detectable local and/or systemic progress. The mean duration of biochemical non-evidence of disease (bNED) after radiation was 12 months for all patients (31% in the 30 Gy group and 42% in the 40 Gy group). No RTOG/EORTC grade III or IV side effects were registered during/after radiotherapy.

CONCLUSION

Combined EBRT and IMBT-boost of TRUS detectable recurrences of prostate cancer after radical prostatectomy seems to be a feasible method of salvage treatment. These early results need to be confirmed by further prospective randomized trials and by longer follow-up in all dose groups.

A prospective randomized study on two dose fractionation regimens of high-dose-rate brachytherapy for carcinoma of the uterine cervix: comparison of efficacies and toxicities between two regimens

To evaluate the toxicities and efficacies of two fractionation regimens of high-dose-rate brachytherapy in uterine cervical cancer, patients were stratified by stage Ib-IIa versus IIb-IVa, and randomly assigned to receive 3 Gy fractions (group A) or 5 Gy fractions (group B). External radiotherapy was performed using a 10 MV radiography with a daily 1.8 Gy up to 30.6 Gy to the whole pelvis, and then with a midline shield up to 45.0 Gy. Brachytherapy was performed with 3 Gy x 10 times or 5 Gy x 5 times, and this was followed by booster brachytherapy of a smaller fraction to the residual tumor. Between August 1999 to July 2000, 46 patients were eligible. Median follow-up period was 42 months (5-49). The range of age was 37-83 yr (median, 58). The three-year disease-specific survival rates of group A (n=23) and B (n=23) were 90.5%, 84.9%, respectively (p=0.64). The three-year pelvic control rates of group A and B were 90.0% and 90.9%, respectively (p=0.92). The incidences of late complications of the rectum or bladder of grade 2 or greater in groups A and B were 23.8% and 9.1%, respectively (p=0.24). Our study showed that the results of two regimens were comparable. Fractionation regimen using 5 Gy fractions seems to be safe and effective, and offers shorter treatment duration.

Intraoperative high-dose-rate brachytherapy for paranasal sinus tumors

PURPOSE

Advanced and recurrent tumors of the paranasal sinuses can be difficult to irradiate to high doses with standard external beam radiotherapy (EBRT), conventional brachytherapy, or intraoperative electron beams. We, therefore, explored the role of intraoperative high-dose-rate brachytherapy (IOHDR) as a boost to EBRT in primary tumors or as sole adjuvant treatment in recurrent disease.

METHODS AND MATERIALS

Between 1992 and 1998, 34 patients with locally advanced tumors arising in the paranasal sinuses were treated with IOHDR after maximal surgical excision. Twenty-seven patients with new primaries underwent gross resection and 10-12.5 Gy IOHDR followed by 45-50 Gy EBRT. Seven previously irradiated (45-63 Gy) patients with recurrent disease were treated with 15-20 Gy of IOHDR alone after gross excision. Local control and overall survival were analyzed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

After a mean follow-up of 6 years (range 34-120 months), the 1-, 3-, and 5-year actuarial survival rate was 80%, 62%, and 44%, respectively. The overall local control rate at 1 and 5 years was 75% and 65%, respectively, and distant failure was documented in 44% of patients. Subgroup analysis revealed that the presence of gross disease after surgical resection was the strongest prognosticator, with a 5-year survival and local control rate of 17% and 50%, respectively, compared with 60% and 68%, respectively, for microscopic disease. The local control rates of patients with new primaries were similar to those of patients treated for recurrent disease (63% vs. 71%), probably because gross residual disease occurred only in the group of patients with new primaries. The addition of EBRT to IOHDR increased the 5-year disease-free survival rate from 27% to 44% but had no effect on local control (64% vs. 65%).

CONCLUSION

IOHDR can be safely used to deliver a high radiation dose to locally advanced and recurrent tumors in the paranasal sinuses. In an attempt to improve outcome, we are now adding limited-dose EBRT (20-30 Gy) after 17.5 Gy of IOHDR in previously irradiated patients and increasing the EBRT dose for both microscopic (50-54 Gy) and gross residual disease (60-65 Gy) after 15 Gy of IOHDR in previously unirradiated patients. Chemosensitization should also be considered in previously irradiated patients and in those with gross residual disease. Interstitial boosting techniques, which can deliver higher doses at depth, should also be considered in patients with gross residual disease.

Amifostine and external beam radiation therapy and/or high-dose rate brachytherapy in the treatment of localized prostate carcinoma: preliminary results of a phase II trial

Local control of carcinoma of the prostate, when treated with radiation therapy, is dose related. It is well documented that higher radiation doses can produce definitive improvement but not without an increased risk of developing gastrointestinal and/or genitourinary toxicities. Radioprotective agents, such as amifostine (Ethyol, WR-2721; MedImmune, Inc, Gaithersburg, MD), have been proven to reduce radiotherapy-induced toxicities to normal tissue in patients with head and neck, thoracic, and pelvic tumors. Based on this information, and in an effort to determine the effectiveness of radioprotective agents in patients with prostate cancer, our institution developed a protocol involving use of amifostine in patients with prostate cancer treated with external beam radiation to a total dose of 45 Gy and/or high-dose rate brachytherapy. High-dose rate doses are 6 Gy times three fractions for combined therapy and 9.3 Gy times four fractions for the monotherapy group. To date, 13 patients have been treated, with preliminary results indicating an acceptably low incidence of gastrointestinal and genitourinary toxicities, including no acute blood pressure changes or skin reactions. However, there have been three cases of severe cardiopulmonary events, which are discussed in detail.

High dose rate brachytherapy in the treatment of prostate cancer

The optimal treatment of patients with localized prostate cancer remains controversial. Significant clinical data are available, however, demonstrating that patients treated with radiation therapy (RT) have a significantly better outcome as the dose to the gland is increased. What remains debatable, however, is how to best deliver these higher doses of RT without significantly increasing normal tissue toxicities. Conformal high dose rate brachytherapy (C-HDR BT) represents an alternative means of precise dose delivery that offers similar tumoricidal effects as three-dimensional (3D) conformal external beam radiotherapy (EBRT) or permanent interstitial prostate seed implants with potential additional advantages. Since C-HDR BT consists of temporarily placing afterloading needles or catheters directly into the prostate gland under real-time ultrasound guidance, a steep dose gradient between the prostate and adjacent normal tissues can be generated that is minimally affected by organ motion and edema or treatment setup uncertainties. The ability to control the amount of time the single HDR radioactive source "dwells" at each position along the length of each brachytherapy catheter further enhances the conformity of the dose. In addition, recent radiobiological data on prostate cancer treatment suggest that C-HDR BT should produce tumor control and late normal tissue side effects that are at least as good as achieved with conventional fractionation, with the additional possibility that acute side effects might be reduced. Published data from several groups performing C-HDR BT as boosts in patients with locally advanced disease have supported these assumptions. Combined with the physical advantages discussed above, C-HDR BT should provide similar tumor control as 3D conformal EBRT with the added advantages of reduced treatment times, less acute toxicity, and no additional technological requirements to account and correct for treatment setup uncertainties and organ motion. Due to the success of C-HDR BT as boost treatment in locally advanced disease, this form of radiation treatment has recently been applied to low-risk prostate cancer patients as an alternative brachytherapy technique to permanent interstitial seed implantation. Advantages in this setting include an improved ability to define and deliver the prescribed dose, a significantly shortened treatment schedule compared to 3D conformal EBRT, and the fact that patients are not radioactive after implantation.

High-dose-rate intracavitary brachytherapy: results of analyses of late rectal complications

PURPOSE

To examine the incidence of radiation-induced late rectal complications by analyzing the data of measured rectal doses in patients with cancer of the uterine cervix treated with high-dose-rate intracavitary brachytherapy.

METHODS AND MATERIALS

We measured doses to the rectum in 105 patients with cancer of the cervix during high-dose-rate intracavitary brachytherapy with a semiconductor dosimeter that can measure five points in the rectum simultaneously. On the basis of these measurements, equivalent doses, to which the biologically equivalent doses were converted as if given as fractionated irradiation at 2 Gy/fraction, were calculated as components of the cumulative dose at five rectal points in intracavitary brachytherapy combined with the external whole pelvic dose.

RESULTS

The calculated values of equivalent doses for late effects at the rectum ranged from 15 to 100 Gy (median 60 Gy for patients who did not develop complications and 76 Gy for patients who subsequently developed Grade II or III complications). When converted to a graph of absolute rectal complication probability, the data could be fitted to a sigmoid curve. The data showed a very definite dose-response relationship, with a threshold for complications at approximately 50 Gy and the curve starting to rise more steeply at approximately 60 Gy. The steepest part of the curve had a slope equivalent to approximately 4% incidence/1 Gy increase in equivalent doses.

CONCLUSION

The radiation tolerance dose, 5% and 50% complication probability, was about 64 and 79 Gy, respectively. Our data almost agree with the prescribed dose for the rectum for the radiation tolerance doses on the basis of the recorded human and animal data. The probability of rectal complications increased drastically after the maximal rectal dose was >60 Gy.

The emerging role of brachytherapy in the management of patients with breast cancer

Brachytherapy remains an important treatment option in the overall management of patients with breast cancer. In patients treated with breast conserving therapy (BCT), prospective randomized trials have established the advantage of a boost in most patients. Interstitial brachytherapy has consistently been shown to provide an important option to boost patients, and in certain clinical settings it may provide a more appropriate means of dose delivery. The concept of delivering partial breast irradiation with accelerated treatment schedules has now provided brachytherapy a new and exciting role in the management of patients treated with BCT. There are now data available from several phase I/II studies suggesting that brachytherapy alone can be used safely and reproducibly in this setting in order to reduce the time, inconvenience, and toxicity associated with traditional radiation therapy. Although preliminary results with brachytherapy alone are encouraging, proper patient selection and optimal dosimetric guidelines must be employed in order to achieve success when used in this setting.

High-dose-rate brachytherapy for vaginal cancer: learning from treatment complications

Historically, early stage vaginal cancer has been treated with low-dose-rate (LDR) brachytherapy with or without external beam radiation therapy (EBRT). Complication rates have been low and treatment efficacious. Although high-dose-rate (HDR) brachytherapy has been used for cervical cancer in many countries for over a decade, only more recently has it been integrated into treatment plans for vaginal cancer. This paper describes three patients treated with HDR brachytherapy who experienced significant late effects. Given the very limited amount of literature regarding the use of HDR brachytherapy in vaginal cancer, this analysis potentially contributes to an understanding of treatment-related risk factors for complications among patients treated with this modality.A focused review of hospital and departmental treatment records was done on three patients treated with HDR brachytherapy. Abstracted information included clinical data, treatment parameters (technique, doses, volume, combinations with other treatments) and outcomes (local control, survival, early and late effects). A review of the available literature was also undertaken. All patients had significant complications. Although statistical correlations between treatment parameters and complications are impossible given the limited number of patients, this descriptive analysis suggests that vaginal length treated with HDR brachytherapy is a risk factor for early and late effects, that the distal vagina has a lower radiation tolerance than the upper vagina with HDR as in LDR, and that combining HDR with LDR as done in our experience carries a high risk of late toxicity. Integration of HDR brachytherapy techniques into treatment plans for early stage vaginal cancers must be done cautiously. The etiology of the significant side effects seen here is likely to be multifactorial. For users of HDR brachytherapy in vaginal cancer, there is a need to further refine and standardize treatment concepts and treatment delivery. Ideally this will be based on continued careful observation and reporting of both favorable and unfavorable outcomes and experiences.

Intraoperative high-dose-rate brachytherapy for the treatment of pediatric tumors: the Ohio State University experience

PURPOSE

To determine whether intraoperative high-dose-rate brachytherapy (IO-HDRBT) can be used to decrease the dose of external beam radiotherapy (EBRT) in the treatment of children with soft-tissue sarcomas and, thereby, reduce morbidity without compromising local control.

METHODS AND MATERIALS

From March 1992 through April 1999, 13 pediatric patients were treated with IO-HDRBT, low-dose EBRT, chemotherapy, and radical surgery at 21 sites that were not amenable to intraoperative electron beam therapy. The IO-HDRBT dose at 5 mm depth was 10 to 12.5 Gy for close margins/microscopic disease at 14 sites and 12.5 to 15 Gy for gross disease at 7 sites. The treatment volumes ranged from 4 to 96 cm(3) (mean 27). The EBRT dose was limited to 27-30 Gy in most cases to minimize growth retardation and preserve normal organ function.

RESULTS

After a median follow-up of 47 months (range 12-97), 11 patients were alive and without evidence of disease (overall survival rate 85%, 4-year actuarial survival rate 77%). Of the 2 who died, 1 had Stage III pulmonary blastoma with a sacral recurrence; the other had Stage IV undifferentiated synovial sarcoma with a pulmonary recurrence. One local failure occurred in a patient with gross residual disease after incomplete resection for Stage IV pulmonary blastoma. The local control rate was 95%, and morbidity was observed in 3 patients (23%). One patient developed impaired orbital growth with mild ptosis. Another patient required orthopedic pinning of her femoral subcapital epiphysis and construction of a neobladder secondary to urethral obstruction. The third patient required reimplantation of her autotransplanted kidney secondary to chronic urinary tract infection and ureteral reflux.

CONCLUSIONS

IO-HDRBT allowed for reduction in EBRT without compromising local control or disease-free survival in children with soft-tissue sarcomas. Tumor beds inaccessible to electron beam methods could be satisfactorily encompassed with IO-HDRBT techniques.

The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for head-and-neck carcinoma

PURPOSE

To develop recommendations for use of high-dose-rate (HDR) brachytherapy in patients with head-and-neck cancer.

METHODS

A panel consisting of members of the American Brachytherapy Society (ABS) performed a literature review, added information based upon their clinical experience, and formulated recommendations for head-and-neck HDR brachytherapy.

RESULTS

The ABS recommends the use of brachytherapy as a component of the treatment of head-and-neck tumors. However, the ABS recognizes that some radiation oncologists are reluctant to employ brachytherapy in the head-and-neck region because of the complexity of the postoperative management and concerns about radiation safety. In this regard, HDR eliminates unwanted radiation exposure and thereby permits unrestricted delivery of clinical care to these brachytherapy patients. The ABS made specific recommendations for previously untreated and recurrent head-and-neck cancer patients on patient selection criteria, implant techniques, target volume definition, and HDR treatment parameters (such as time, dose, and fractionation schedules). Suggestions were provided for treatment with HDR alone and in combination with external beam radiation therapy. It should be recognized that only limited experiences exist with HDR brachytherapy in patients with head-and-neck cancers. Therefore, some of these suggested doses have not been extensively tested in clinical practice. Hence, these guidelines will be updated as significant new outcome data are available. Any clinician following these guidelines is expected to use clinical judgment to determine an individual patient's treatment.

CONCLUSIONS

Little has been published in the clinical literature on HDR brachytherapy in head-and-neck cancer. Based upon the available information and the clinical experience of the panel members, general and site-specific recommendations were offered. Areas for further investigations were identified.

High-dose-rate brachytherapy in the treatment of uterine cervix cancer. Analysis of dose effectiveness and late complications

PURPOSE

This retrospective analysis aims to report results of patients with cervix cancer treated by external beam radiotherapy (EBR) and high-dose-rate (HDR) brachytherapy.

METHODS AND MATERIALS

From September 1992 to December 1996, 138 patients with FIGO Stages II and III and mean age of 56 years were treated. Median EBR to the whole pelvis was 45 Gy in 25 fractions. Parametrial boost was performed in 93% of patients, with a median dose of 14.4 Gy. Brachytherapy with HDR was performed during EBR or following its completion with a dose of 24 Gy in four weekly fractions of 6 Gy to point A. Median overall treatment time was of 60 days. Patient age, tumor stage, and overall treatment time were variables analyzed for survival and local control. Cumulative biologic effective dose (BED) at rectal and bladder reference points were correlated with late complications in these organs and dose of EBR at parametrium was correlated with small bowel complications.

RESULTS

Median follow-up time was 38 months. Overall survival, disease-free survival, and local control at 5 years was 53.7%, 52.7%, and 62%, respectively. By multivariate and univariate analysis, overall treatment time up to 50 days was the only statistically significant adverse variable for overall survival (p = 0.003) and actuarial local control (p = 0.008). The 5-year actuarial incidence of rectal, bladder, and small bowel late complications was 16%, 11%, and 14%, respectively. Patients treated with cumulative BED at rectum points above 110 Gy(3) and at bladder point above 125 Gy(3) had a higher but not statistically significant 5-year actuarial rate of complications at these organs (18% vs. 12%, p = 0.49 and 17% vs. 9%, p = 0.20, respectively). Patients who received parametrial doses larger than 59 Gy had a higher 5-year actuarial rate of complications in the small bowel; however, this was not statistically significant (19% vs. 10%, p = 0.260).

CONCLUSION

This series suggests that 45 Gy to the whole pelvis combined with four fractions of 6 Gy to point A with HDR brachytherapy is an effective and safe fractionation schedule in the treatment of Stages II and III cervix cancer if realized up to 50 days. To decrease the small bowel complications, we decreased the superior border of the parametrial fields to the S2-S3 level and the total dose to 54 Gy.

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.

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

PURPOSE

To develop recommendations for use of high-dose-rate (HDR) brachytherapy in patients with endometrial cancer.

METHODS

A panel of members of the American Brachytherapy Society (ABS) performed a literature review, supplemented their clinical experience, and formulated recommendations for endometrial HDR brachytherapy.

RESULTS

The ABS endorses the National Comprehensive Cancer Network (NCCN) guidelines for indications for radiation therapy for patients with endometrial cancer and the guidelines on HDR quality assurance of the American Association on Physicists in Medicine (AAPM). The ABS made specific recommendations for HDR applicator selection, insertion techniques, target volume definition, dose fractionation, and specifications for postoperative adjuvant vaginal cuff therapy, for vaginal recurrences, and for medically inoperable primary endometrial cancer patients. The ABS recommends that applicator selection should be based on patient and target volume geometry. The dose prescription point should be clearly specified. The treatment plan should be optimized to conform to the target volume whenever possible while recognizing the limitations of computer optimization. Suggested doses were tabulated for treatment with HDR alone, and in combination with external beam radiation therapy (EBRT), when applicable. For intravaginal brachytherapy, the largest diameter applicator should be selected to ensure close mucosal apposition. Doses should be reported both at the vaginal surface and at 0.5-cm depth irrespective of the dose prescription point. For vaginal recurrences, intracavitary brachytherapy should be restricted to patients with nonbulky (< 0.5-cm thick) disease. Patients with bulky (> 0.5-cm thick) recurrences should be treated with interstitial techniques. For medically inoperable patients, an appropriate applicator that will allow adequate irradiation of the entire uterus should be selected.

CONCLUSION

Recommendations are made for HDR brachytherapy for endometrial cancer. Practitioners and cooperative groups are encouraged to use these recommendations to formulate their treatment and dose reporting policies. This will lead to meaningful comparisons of reports from different institutions and lead to advances and appropriate use of HDR.

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.