A randomized patient education trial investigating treatment-related distress and satisfaction with the use of an at-home gynecologic brachytherapy educational video.

BACKGROUND: Physician explanation of gynecologic brachytherapy can be overwhelming or induce patient anxiety, and may be time-constrained given clinical limitations. We report the first randomized trial of an educational video intervention in gynecologic brachytherapy on patient-reported outcomes. METHODS: Between February 2020 and January 2022, 80 gynecologic cancer patients prescribed brachytherapy were randomly assigned to either standard informed consent (Arm A) or a supplemental 16 min brachytherapy educational video (https://vimeo.com/403385455/d0716e3cc8) via the internet (Arm B). Primary outcome was treatment-related distress (National Comprehensive Cancer Network (NCCN) distress scale scored 0 (no distress) to 10 (maximum distress)). Secondary outcome was patient satisfaction (summated Likert-scale scored 11-55). Surveys were administered at baseline, after first treatment, and prior to brachytherapy completion. RESULTS: All patients completed the prescribed brachytherapy. In Arm B, 19/40 (48%) patients and 10/40 (25%) patients' family/friends viewed the video. For patients that completed all surveys (Arm A n=29, Arm B n=28), there was no difference between arms in the sociodemographic, clinical, or treatment variables. Distress scores were low at baseline (Arm A median 4, Arm B median 4, p=0.65) and there was no detectable change in distress between arms on surveys 1 and 2 (ß 0.36, p=0.67) or surveys 1 and 3 (ß -1.02, p=0.29) in multivariable analysis. Satisfaction scores were high at baseline (Arm A median 54, Arm B median 54.5, p=0.64) and there was no detectable change in satisfaction between arms on surveys 1 and 2 (ß 0.22, p=0.93) or surveys 1 and 3 (ß 0.63, p=0.85) in multivariable analysis. CONCLUSIONS: Among patients randomized to an educational video tool for gynecologic brachytherapy, approximately 50% of the cohort and 25% of the cohort's family/friends used the video. Overall, patients had low distress scores and high satisfaction scores with no significant differences between the standard and video intervention arms. Further work is needed to understand factors contributing to gynecologic brachytherapy anxiety. TRIAL REGISTRATION NUMBER: NCT04363957.

AAPM medical physics practice guideline 13.a: HDR brachytherapy, part A.

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines (MPPGs) will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (1) Must and must not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (2) Should and should not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances. Approved by AAPM's Executive Committee April 28, 2022.

Immediate post-operative brachytherapy prior to irradiation and temozolomide for newly diagnosed glioblastoma.

To determine whether immediate post-operative brachytherapy can be safely applied to newly diagnosed glioblastomas to retard tumor progression prior to initiation of external beam radiation therapy (EBRT) and temozolomide. Between 1996 and 2011, eleven patients underwent implantation of GliaSite (n = 9) or MammoSite (n = 2) at the time of surgical resection. Brachytherapy was carried out on post-operative day 2-3, with 45-60 Gy delivered to a 1 cm margin. All patients underwent subsequent standard radiation/temozolomide treatment 4-5 weeks post-irradiation. There were no wound related complications. Toxicity was observed in two patients (2/11 or 18 %), including one post-operative seizure and one case of cerebral edema that resolved after a course of steroid treatment. Immediate post-operative and pre-irradiation/temozolomide magnetic resonance imaging assessment was available for 9 of the 11 patients. Two of these nine patients (22 %) developed new regions of contrast enhancement prior to irradiation/temozolomide. This compares favorably to historical data where 53 % of patient suffer such tumor progression. While there was a trend toward improved 6 month progression free survival in the brachytherapy/temozolomide/radiation treated patients, the overall survival of these patients were comparable to historical controls. This case series demonstrates the safety of immediate post-operative brachytherapy when applied prior to EBRT and temozolomide in the treatment of newly diagnosed glioblastomas.

Outcomes from a 3-fraction high-dose-rate brachytherapy regimen for patients with cervical cancer.

PURPOSE: To estimate local control, survival, and toxicity associated with a 3-fraction (3F) image-guided brachytherapy (IGBT) regimen compared to longer fraction (LF) for cervical cancer. METHODS: 150 patients treated between 2015-2020 with 3F (24Gy in 3 fractions) or LF (28...30 Gy in 4-5 fractions) were reviewed. The primary outcome was 2-year local failure. We compared overall survival (OS), disease-free survival (DFS), hospitalizations, and toxicity. RESULTS: There were 32 patients in the 3F group and 118 in the LF group, with a median follow up of 22 months. The 3F had worse performance status (p = 0.01) but otherwise similar characteristics. The 2-year local failure rate was 3.6% (95% CI 0%, 10.6%) for 3F, and 7.5% (95% CI 2.4%, 12.6%) for LF. The univariable hazard ratio (HR) for local failure for 3F was 0.43 (0.05, 3.43; p = 0.43). Moreover, 2 of 32 (6.3%) 3F patients experienced Grade ...3 toxicity compared to 7 of 118 (5.9%) LF patients (p = 1.0), with no difference in hospitalization within 2 years (p = 0.66) and no treatment-related deaths. CONCLUSIONS: Local control was excellent, with long term survival and toxicity similar between the groups. These findings support consideration of 3F.

Three-Fraction Accelerated Partial Breast Irradiation (APBI) Delivered With Interstitial Brachytherapy Is Safe: First Results From the Tri-fraction Radiation Therapy Used to Minimize Patient Hospital Trips (TRIUMPH-T) Trial.

PURPOSE: Shorter courses of breast radiotherapy are offered as an alternative to 4 weeks of whole-breast irradiation after lumpectomy, including brachytherapy. A prospective phase 2multi-institution clinical trial to study 3-fraction accelerated partial breast irradiation delivered by brachytherapy was conducted. METHODS AND MATERIALS: The trial treated selected breast cancers after breast-conserving surgery with brachytherapy applicators that delivered 22.5 Gy in 3 fractions of 7.5 Gy. The planning treatment volume was 1 to 2 cm beyond the surgical cavity. Eligible women were age ≥45 years with unicentric invasive or in situ tumors ≤3 cm excised with negative margins and with positive estrogen or progesterone receptors and no metastases to axillary nodes. Strict dosimetric parameters were required to be met and follow up information was collected from the participating sites. RESULTS: Two hundred patients were prospectively enrolled; however, a total of 185 patients who were enrolled were followed for a median of 3.63 years. Three-fraction brachytherapy was associated with low chronic toxicity. There was excellent or good cosmesis in 94% of patients. There were no grade 4 toxicities. Grade 3 fibrosis at the treatment site was present in 1.7% and 32% percent had grades 1 or 2 fibrosis at the treatment site. There was 1 rib fracture. Other late toxicities included 7.4% grade 1 hyperpigmentation, 2% grade 1 telangiectasias, 1.7% symptomatic seromas, 1.7% abscessed cavities, and 1.1% symptomatic fat necrosis. There were 2 (1.1%) ipsilateral local recurrences, 2 (1.1%) nodal recurrences and no distant recurrences. Other incidents included one contralateral breast cancer and 2 second malignancies (lung). CONCLUSIONS: Ultra-short breast brachytherapy is feasible and has excellent toxicity and could be an alternative to standard 5-day, 10 fraction accelerated partial breast irradiation in eligible patients. Patients from this prospective trial will continue to be followed to evaluate long-term outcomes.

Retrospective review of three-fractioned accelerated partial breast irradiation.

METHODS: This retrospective study evaluated patients who received three-fraction accelerated partial breast irradiation (APBI) via brachytherapy for breast cancer between January 2016 and April 2020. Inclusion criteria included age ≥18 years and early-stage unilateral breast cancer with negative lymph nodes. We evaluated acute toxicity (<6 weeks), late toxicity (≥6 weeks), and cosmetic outcomes. Frequencies of each variable were calculated. Cancer-specific outcomes were determined via the Kaplan-Meier method. RESULTS: Thirty consecutive patients received three-fraction APBI of 2,250 cGy over 2 d. All cancers were stage T2 or less. Median time to last follow-up was 22 months. Local recurrence-free survival was 95.8% at 22 months. Seventeen (56.7%) patients reported an acute toxicity event. All were grade 1 except one patient with grade 2 (fatigue). No patient experienced ≥ grade 3 acute toxicity. One (3.3%) patient reported grade 3 late toxicity (tissue fibrosis). No patients had breast edema, fat necrosis, or non-healing wounds. There were no ≥ grade 3 cosmetic events. DISCUSSION: Three-fraction APBI via brachytherapy was successful in preventing disease recurrence and death in this study, with still limited follow-up. Although acute and late toxicities or adverse cosmetic outcomes were seen, very few were grade 2 or higher and compare favorably to those reported in prior 10-fraction APBI studies. CONCLUSIONS: This study provides early single institutional evidence that three-fraction APBI may become a feasible treatment alternative.

Partial breast irradiation: An updated consensus statement from the American brachytherapy society.

PURPOSE: In recent years, results with mature follow-up have been reported for several Phase III trials randomizing women to receive whole breast irradiation (WBI) versus varying modalities of partial breast irradiation (PBI). It is important to recognize that these methods vary in terms of volume of breast tissue treated, dose per fraction, and duration of therapy. As such, clinical and technical guidelines may vary among the various PBI techniques. METHODS: Members of the American Brachytherapy Society with expertise in PBI performed an extensive literature review focusing on the highest quality data available for the numerous PBI options offered in the modern era. Data were evaluated for strength of evidence and published outcomes were assessed. RESULTS: The majority of women enrolled on randomized trials of WBI versus PBI have been age >45 years with tumor size <3 cm, negative margins, and negative lymph nodes. The panel also concluded that PBI can be offered to selected women with estrogen receptor negative and/or Her2 amplified breast cancer, as well as ductal carcinoma in situ, and should generally be avoided in women with extensive lymphovascular space invasion. CONCLUSIONS: This updated guideline summarizes published clinical trials of PBI methods. The panel also highlights the role of PBI for women facing special circumstances, such as history of cosmetic breast augmentation or prior breast irradiation, and discusses promising novel modalities that are currently under study, such as ultrashort and preoperative PBI. Updated consensus guidelines are also provided to inform patient selection for PBI and to characterize the strength of evidence to support varying PBI modalities.

Monomethyl auristatin antibody and peptide drug conjugates for trimodal cancer chemo-radio-immunotherapy.

Locally advanced cancers remain therapeutically challenging to eradicate. The most successful treatments continue to combine decades old non-targeted chemotherapies with radiotherapy that unfortunately increase normal tissue damage in the irradiated field and have systemic toxicities precluding further treatment intensification. Therefore, alternative molecularly guided systemic therapies are needed to improve patient outcomes when applied with radiotherapy. In this work, we report a trimodal precision cytotoxic chemo-radio-immunotherapy paradigm using spatially targeted auristatin warheads. Tumor-directed antibodies and peptides conjugated to radiosensitizing monomethyl auristatin E (MMAE) specifically produce CD8 T cell dependent durable tumor control of irradiated tumors and immunologic memory. In combination with ionizing radiation, MMAE sculpts the tumor immune infiltrate to potentiate immune checkpoint inhibition. Here, we report therapeutic synergies of targeted cytotoxic auristatin radiosensitization to stimulate anti-tumor immune responses providing a rationale for clinical translational of auristatin antibody drug conjugates with radio-immunotherapy combinations to improve tumor control.

Hyper-dense foreign bodies found in the bowel during IGRT following brachytherapy.

A 28-year-old female with locally advanced adenocarcinoma of the cervix was undergoing treatment with external beam radiation therapy (EBRT), concurrent chemotherapy and high dose rate brachytherapy (BT). On-board imaging obtained prior to one of her external beam treatments revealed four radiopaque foreign bodies in her abdomen. The patient's treatment was delayed for further work-up of this new finding. Upon further investigation, it was discovered that the patient had recently started taking bismuth subsalicylate tablets (brand name: Pepto-Bismol, Procter & Gamble Co., Cincinnati, OH). A computed tomography (CT) scan of the tablets confirmed the size and Hounsfield Unit (HU) values coincided with the foreign object properties seen on the patient's scan. This unexpected finding is important to recognize as it consequently lead to a delay in treatment, additional imaging, and patient anxiety.

Evaluation of dose differences between intracavitary applicators for cervical brachytherapy using knowledge-based models.

PURPOSE: Currently, there is a lack of patient-specific tools to guide brachytherapy planning and applicator choice for cervical cancer. The purpose of this study is to evaluate the accuracy of organ-at-risk (OAR) dose predictions using knowledge-based intracavitary models, and the use of these models and clinical data to determine the dosimetric differences of tandem-and-ring (T&R) and tandem-and-ovoids (T&O) applicators. MATERIALS AND METHODS: Knowledge-based models, which predict organ D2cc, were trained on 77/75 cases and validated on 32/38 for T&R/T&O applicators. Model performance was quantified using ΔD2cc=D2cc,actual-D2cc,predicted, with standard deviation (σ(ΔD2cc)) representing precision. Model-predicted applicator dose differences were determined by applying T&O models to T&R cases, and vice versa, and compared to clinically-achieved D2cc differences. Applicator differences were assessed using a Student's t-test (p < 0.05 significant). RESULTS: Validation T&O/T&R model precision was 0.65/0.55 Gy, 0.55/0.38 Gy, and 0.43/0.60 Gy for bladder, rectum and sigmoid, respectively, and similar to training. When applying T&O/T&R models to T&R/T&O cases, bladder, rectum and sigmoid D2cc values in EQD2 were on average 5.69/2.62 Gy, 7.31/6.15 Gy and 3.65/0.69 Gy lower for T&R, with similar HRCTV volume and coverage. Clinical data also showed lower T&R OAR doses, with mean EQD2 D2cc deviations of 0.61 Gy, 7.96 Gy (p < 0.01) and 5.86 Gy (p < 0.01) for bladder, rectum and sigmoid. CONCLUSIONS: Accurate knowledge-based dose prediction models were developed for two common intracavitary applicators. These models could be beneficial for standardizing and improving the quality of brachytherapy plans. Both models and clinical data suggest that significant OAR sparing can be achieved with T&R over T&O applicators, particularly for the rectum.

Knowledge-based dose prediction models to inform gynecologic brachytherapy needle supplementation for locally advanced cervical cancer.

PURPOSE: The use of interstitial needles, combined with intracavitary applicators, enables customized dose distributions and is beneficial for complex cases, but increases procedure time. Overall, applicator selection is not standardized and depends on physician expertise and preference. The purpose of this study is to determine whether dose prediction models can guide needle supplementation decision-making for cervical cancer. MATERIALS AND METHODS: Intracavitary knowledge-based models for organ-at-risk (OAR) dose estimation were trained and validated for tandem-and-ring/ovoids (T&R/T&O) implants. Models were applied to hybrid cases with 1-3 implanted needles to predict OAR dose without needles. As a reference, 70/67 hybrid T&R/T&O cases were replanned without needles, following a standardized procedure guided by dose predictions. If a replanned dose exceeded the dose objective, the case was categorized as requiring needles. Receiver operating characteristic (ROC) curves of needle classification accuracy were generated. Optimal classification thresholds were determined from the Youden Index. RESULTS: Needle supplementation reduced dose to OARs. However, 67%/39% of replans for T&R/T&O met all dose constraints without needles. The ROC for T&R/T&O models had an area-under-curve of 0.89/0.86, proving high classification accuracy. The optimal threshold of 99%/101% of the dose limit for T&R/T&O resulted in classification sensitivity and specificity of 78%/86% and 85%/78%. CONCLUSIONS: Needle supplementation reduced OAR dose for most cases but was not always required to meet standard dose objectives, particularly for T&R cases. Our knowledge-based dose prediction model accurately identified cases that could have met constraints without needle supplementation, suggesting that such models may be beneficial for applicator selection.

Comparison of computed tomography and magnetic resonance imaging in cervical cancer brachytherapy target and normal tissue contouring.

OBJECTIVE: To evaluate the differences between target and normal tissue delineation between magnetic resonance imaging (MRI) and computed tomography (CT) in cervical cancer patients and to explore the differences in dosimetry after brachytherapy planning. METHODS: High-dose-rate brachytherapy was performed on 11 patients. Planning CT and MRI were performed with tandem and ring in place. The radiation oncologist contoured the rectum, the bladder, the sigmoid, and the high-risk clinical target volume (HR-CTV) on CT and MRI. The values compared between CT and MRI included D90 and D100 to HR-CTV; coronal, sagittal, and axial measurements of HR-CTV; and minimum dose to most irradiated 0.1-, 0.5-, 1.0-, and 2.0-cm volumes for the organs at risk (OAR). Doses were converted to the equivalent dose in 2 Gy by applying the linear quadratic model. Volume optimization was also performed, and the above parameters were evaluated. RESULTS: Magnetic resonance imaging showed a significantly greater HR-CTV length in the sagittal plane (P = 0.006), with CT showing a greater length in the coronal plane (P = 0.004). The equivalent dose in 2 Gy to 2.0 cm for the bladder was greater on CT than MRI (P = 0.041). The remainder of the dose volume histogram values for the OAR were similar between CT and MRI. With volume optimization, no significant differences were seen between HR-CTV dose parameters or doses to OAR. CONCLUSIONS: The CT- and MRI-based brachytherapy tissue delineation seems adequate for evaluation of OAR and target tissues, although the shapes of HR-CTV and OAR do differ. When adopting volume-based prescription, these differences may lead to altered target dosing. The clinical impact of these differences seems to be small and may demonstrate that planning with CT, if combined with one MRI, may be sufficient.

Development, implementation, and associated challenges of a new HDR brachytherapy program.

Developing any new radiation oncology program requires planning and analysis of the current state of the facility and its capacity to take on another program. Staff must consider a large number of factors to establish a feasible, safe, and sustainable program. We present a simple and generic outline that lays out the process for developing and implementing a new HDR brachytherapy program in any setting, but with particular emphasis on challenges associated with starting the program in a limited resource setting. The sections include feasibility of a program, starting cases, machine and equipment selection, and quality and safety.

A knowledge-based organ dose prediction tool for brachytherapy treatment planning of patients with cervical cancer.

PURPOSE: The purpose of this study is to explore knowledge-based organ-at-risk dose estimation for intracavitary brachytherapy planning for cervical cancer. Using established external-beam knowledge-based dose-volume histogram (DVH) estimation methods, we sought to predict bladder, rectum, and sigmoid D2cc for tandem and ovoid treatments. METHODS AND MATERIALS: A total of 136 patients with loco-regionally advanced cervical cancer treated with 456 (356:100 training:validation ratio) CT-based tandem and ovoid brachytherapy fractions were analyzed. Single fraction prescription doses were 5.5-8 Gy with dose criteria for the high-risk clinical target volume, bladder, rectum, and sigmoid. DVH estimations were obtained by subdividing training set organs-at-risk into high-risk clinical target volume boundary distance subvolumes and computing cohort-averaged differential DVHs. Full DVH estimation was then performed on the training and validation sets. Model performance was quantified by ΔD2cc = D2cc(actual)-D2cc(predicted) (mean and standard deviation). ΔD2cc between training and validation sets were compared with a Student's t test (p < 0.01 significant). Categorical variables (physician, fraction-number, total fractions, and case complexity) that might explain model variance were examined using an analysis of variance test (Bonferroni-corrected p < 0.01 threshold). RESULTS: Training set deviations were bladder ΔD2cc = -0.04 ± 0.61 Gy, rectum ΔD2cc = 0.02 ± 0.57 Gy, and sigmoid ΔD2cc = -0.05 ± 0.52 Gy. Model predictions on validation set did not statistically differ: bladder ΔD2cc = -0.02 ± 0.46 Gy (p = 0.80), rectum ΔD2cc = -0.007 ± 0.47 Gy (p = 0.53), and sigmoid ΔD2cc = -0.07 ± 0.47 Gy (p = 0.70). The only significant categorical variable was the attending physician for bladder and rectum ΔD2cc. CONCLUSION: A simple boundary distance-driven knowledge-based DVH estimation exhibited promising results in predicting critical brachytherapy dose metrics. Future work will examine the utility of these predictions for quality control and automated brachytherapy planning.

Precision Chemoradiotherapy for HER2 Tumors Using Antibody Conjugates of an Auristatin Derivative with Reduced Cell Permeability.

The most successful therapeutic strategies for locally advanced cancers continue to combine decades-old classical radiosensitizing chemotherapies with radiotherapy. Molecular targeted radiosensitizers offer the potential to improve the therapeutic ratio by increasing tumor-specific kill while minimizing drug delivery and toxicity to surrounding normal tissue. Auristatins are a potent class of anti-tubulins that sensitize cells to ionizing radiation damage and are chemically amenable to antibody conjugation. To achieve tumor-selective radiosensitization, we synthesized and tested anti-HER2 antibody-drug conjugates of two auristatin derivatives with ionizing radiation. Monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF) were attached to the anti-HER2 antibodies trastuzumab and pertuzumab through a cleavable linker. While MMAE is cell permeable, MMAF has limited cell permeability as free drug resulting in diminished cytotoxicity and radiosensitization. However, when attached to trastuzumab or pertuzumab, MMAF was as efficacious as MMAE in blocking HER2-expressing tumor cells in G2-M. Moreover, MMAF anti-HER2 conjugates selectively killed and radiosensitized HER2-rich tumor cells. Importantly, when conjugated to targeting antibody, MMAF had the advantage of decreased bystander and off-target effects compared with MMAE. In murine xenograft models, MMAF anti-HER2 antibody conjugates had less drug accumulated in the normal tissue surrounding tumors compared with MMAE. Therapeutically, systemically injected MMAF anti-HER2 conjugates combined with focal ionizing radiation increased tumor control and improved survival of mice with HER2-rich tumor xenografts. In summary, our results demonstrate the potential of cell-impermeable radiosensitizing warheads to improve the therapeutic ratio of radiotherapy by leveraging antibody-drug conjugate technology.

Implementation of peer-review quality rounds for gynecologic brachytherapy in a high-volume academic center.

PURPOSE: While peer review is critical for quality and safety in radiotherapy, there are neither formal guidelines nor format examples for brachytherapy (BT) peer review. We report on a gynecologic BT peer-review method implemented at a high-volume academic center. METHODS AND MATERIALS: We analyzed discussions at bimonthly gynecologic BT peer-review rounds between July and December 2018. Rounds consisted of 2-5 attending physicians with gynecologic BT expertise, 1-2 BT physicists, and trainees. Peer-review targets included clinical case review, contours, implant technique, dose/fractionation, and target/organ-at-risk (OAR) dosimetry. The projected/final target and OAR dosimetry were analyzed. RESULTS: 55 separate implants from 44 patients were reviewed. Implants were mostly reviewed after the first BT fraction (n = 16, 29%) or at another time point during BT (n = 20, 36%). One (2%) implant was presented prospectively. The applicator type and BT technique were reviewed for all implants. Dose/fractionation was evaluated for 46 implants (84%); contours were discussed for 21 (38%). Target and OAR dosimetry were reviewed for 54 (98%) and 28 implants (51%), respectively. Six cases (11%) underwent minor changes to the applicator type to improve target and/or OAR dosimetry. One case (2%) had a major change recommended to the dose/fractionation. CONCLUSIONS: Gynecologic BT peer review may enhance BT quality by allowing for implant optimization and formal review of challenging cases, ultimately improving medical decision-making and team communication. Peer review should be implemented in centers offering gynecologic BT.

Clinical implementation of a new HDR brachytherapy device for partial breast irradiation.

PURPOSE: To present the clinical implementation of a new HDR device for partial breast irradiation, the Strut-Adjusted Volume Implant (SAVI), at the University of California, San Diego. METHODS AND MATERIALS: The SAVI device has multiple peripheral struts that can be differentially loaded with the HDR source. Planning criteria used for evaluation of the treatment plans included the following dose volume histogram (DVH) criteria: V90 >90%, V150 <50cc and V200 <20cc. RESULTS: SAVI has been used on 20 patients to date at UC San Diego. In each case, the dose was modulated according to patient-specific anatomy to cover the tumor bed, while sparing normal tissues. The dosimetric data show that we can achieve greater than 90% coverage with respect to V90 (median of 95.3%) and also keep a low V150 and V200 dose at 24.5 and 11.2cc, respectively. Complete treatment can be done within a 30-min time slot, which includes implant verification, setup, and irradiation time as well as wound dressing. CONCLUSION: SAVI has been implemented at UC San Diego for accelerated partial breast irradiation with excellent tumor bed conformance and minimal normal tissue exposure. Patient positioning is the key to identifying any inter-fraction device motion. Device asymmetry or tissue conformance has been shown to resolve itself 24h after the device implantation. The device can be implemented into an existing HDR program with minimal effort.

Unexpected toxicity in a patient treated with 3D conformal accelerated partial breast radiotherapy.

INTRODUCTION: With the publication of several trials demonstrating equivalence between partial breast irradiation and whole breast irradiation, the popularity of partial breast radiation has increased. Methods of delivery include interstitial brachytherapy, intracavitary brachytherapy, and 3D conformal irradiation, although the least amount of data exists on 3D conformal. Despite the relative paucity of data on 3D conformal, it is the most common method delivered on the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39 trial. To date, minimal toxicities and good cosmetic results have been associated with accelerated partial breast irradiation. METHODS AND MATERIAL: In this case study, we present a 64-year-old female patient, diagnosed with Grade 1 tubular carcinoma, who developed both expected and unexpected toxicities after 3D conformal accelerated partial breast irradiation. DISCUSSION/RESULTS/CONCLUSION: Along with chest wall pain, she developed hyperpigmentation of the skin as well as fibrosis of the skin, pectoralis minor, and pectoralis major. The fibrosis she developed limited her comfortable range of motion in the ipsilateral arm. She also developed symptomatic fractures of the fourth and fifth ribs in the anterior axillary line. Upon fusing the treatment-planning CT with a diagnostic CT, it was evident that the rib fractures fell within the 100% isodose line of the 3D conformal plan.

Evaluation of three APBI techniques under NSABP B-39 guidelines.

This work compares two accelerated partial breast irradiation modalities, MammoSite brachytherapy and three dimensional conformal radiotherapy (3D-CRT), to a new method, SAVI brachytherapy, following NSABP B-39 guidelines. A total of 21 patients treated at UC San Diego with the SAVI device were evaluated in this comparison. 9 of the 21 patients were eligible for all three modalities and were dosimetrically compared evaluating V90, V150, V200, total target volume, maximum skin, lung, and chestwall/rib dose. The target volumes (PTV_EVAL) differed with SAVI having the least total volume at 59.9 cc vs. 71.5 cc and 351.6 cc for MammoSite and 3D-CRT, respectively. The median V90, V150 and V200 for the three modalities were 97.7%, 25.0 cc, 10.4 cc (SAVI) vs. 97.6%, 23.9 cc, 5.0 cc (MammoSite) vs. 100% (V90 3D-CRT). The maximum dose for SAVI, MammoSite, and 3D-CRT, respectively, relative to the prescribed dose, for the: lung was 80.0%, 150.0%, and 104.9%; for rib 108.8%, 225.0%, and 114.7%: for skin 75.0%, 135.0%, and 108.6%. Comparing modalities, PTV coverage varied between 97.6% - 100.0% with more breast tissue covered by 3D-CRT, as expected, given the differences between external beam and brachytherapy. The maximum lung, skin and rib doses were lowest for the SAVI, highlighting its ability to conform to exclude normal tissues. In offering partial breast radiation, the availability of a variety of techniques allows for maximal patient eligibility, and comparison of individual method pros and cons may guide the most appropriate choice for each patient.

Compendium of fractionation choices for gynecologic HDR brachytherapy-An American Brachytherapy Society Task Group Report.

PURPOSE: The purpose of this study was to report a list of accepted fractionation schemes for high-dose-rate (HDR) brachytherapy for gynecological cancers in a definitive, neoadjuvant, or adjuvant setting. METHODS AND MATERIALS: Members of the American Brachytherapy Society (ABS) Task Force with expertise in gynecological brachytherapy reviewed the literature and existing ABS guidelines regarding various dose-fractionation schedules for HDR brachytherapy to create this compendium. Other resources include current guidelines published by medical societies, clinical trials, the published medical literature, and the clinical experience of the ABS Task Force members. The ABS consensus statements for HDR brachytherapy practice were reviewed for these fractionation schemes and form the major source for this report. Specific recommendations for therapy and recommendations for further investigations were made when there was agreement. RESULTS: A variety of dose-fractionation schedules for HDR brachytherapy alone or integrating brachytherapy with external-beam radiation exist. The choice of a given fractionation schedule may be appropriate depending on the practice situation for the patient and the resources available. While there is no single optimal dose-fractionation scheme for any disease site or clinical situation, higher doses per fraction with fewer fractions per regimen have been known to increase toxicity. The corresponding 2-Gray (Gy) per fraction radiobiologic equivalent doses have been provided (normalized therapy dose) to compare the various regimens where indicated and can be used to estimate isoeffective schedules. CONCLUSIONS: This compendium of HDR brachytherapy fractionation schedules provides various options to the gynecologic brachytherapist and a ready reference for clinical use in the management of gynecological cancer treatments.