Future Industrial Applications: Exploring LPWAN-Driven IoT Protocols.

The Internet of Things (IoT) will bring about the next industrial revolution in Industry 4.0. The communication aspect of IoT devices is one of the most critical factors in choosing the device that is suitable for use. Thus far, the IoT physical layer communication challenges have been met with various communications protocols that provide varying strengths and weaknesses. This paper summarizes the network architectures of some of the most popular IoT wireless communications protocols. It also presents a comparative analysis of some of the critical features, including power consumption, coverage, data rate, security, cost, and quality of service (QoS). This comparative study shows that low-power wide area network (LPWAN)-based IoT protocols (LoRa, Sigfox, NB-IoT, LTE-M) are more suitable for future industrial applications because of their energy efficiency, high coverage, and cost efficiency. In addition, the study also presents an Industrial Internet of Things (IIoT) application perspective on the suitability of LPWAN protocols in a particular scenario and addresses some open issues that need to be researched. Thus, this study can assist in deciding the most suitable IoT communication protocol for an industrial and production field.

A multipurpose brachytherapy catheter to enable intratumoral injection.

PURPOSE: To create and test a multipurpose brachytherapy catheter prototype enabling intratumoral injection and brachytherapy after a single catheter insertion. METHODS AND MATERIALS: The design of the prototype consists of an outer tube and an inner syringe tube that can be filled with injectable agent. The outer sheath and inner syringe tube were constructed using polytetrafluoroethylene tubing, and the other components were 3D printed using dental resin and polylactic acid material. To demonstrate functionality, we injected in vitro phantoms with dyed saline. For proof of concept, we demonstrated the potential for the prototype to deliver cell therapy, enhance tumor delineation, deliver tattoo ink for pathology marking, avoid toxicity through local delivery of chemotherapy, and facilitate combination brachytherapy and immunotherapy. RESULTS: The prototype enables accurate injection in vitro and in vivo without altering dosimetry. To illustrate the potential for delivery of cell therapies, we injected luciferase-expressing splenocytes and confirmed their delivery with bioluminescence imaging. To demonstrate feasibility of radiographically visualizing injected material, we delivered iohexol contrast intratumorally and confirmed tumor retention using Faxitron x-ray imaging. In addition, we show the potential of intratumoral administration to reduce toxicity associated with cyclophosphamide compared with systemic administration. To demonstrate feasibility, we treated tumor-bearing mice with brachytherapy (192Ir source, 2 Gy to 5 mm) in combination with intratumoral injection of 375,000 U of interleukin 2 and observed no increased toxicity. CONCLUSIONS: These results demonstrate that a prototype multipurpose brachytherapy catheter enables accurate intratumoral injection and support the feasibility of combining intratumoral injection with brachytherapy.

Low cardiac and left anterior descending coronary artery dose achieved with left-sided multicatheter interstitial-accelerated partial breast irradiation.

PURPOSE: Studies have shown that an additional mean dose of 1 Gy to the heart can increase the relative risk of cardiac events. The purpose of this study was to quantify the dose delivered to the heart and left anterior descending artery (LAD) in a series of patients with left-sided breast cancer (BC) or ductal carcinoma in situ treated with multicatheter-accelerated partial breast irradiation (MC-APBI) at a single institution. METHODS AND MATERIALS: Patients with left-sided BC or ductal carcinoma in situ treated consecutively from 2005 to 2011 with MC-APBI were retrospectively identified. Cardiac and LAD contours were generated for each patient. Cardiac dosimetry and distance to the planning target volume were recorded. Patient health records were reviewed and cardiac events were recorded based on Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Twenty consecutive patients with left-sided BC treated with MC-APBI were retrospectively identified. Median followup was 41.4 months. Mean equivalent dose in 2 Gy fractions delivered to the heart and LAD were 1.3 (standard deviation: 0.7, range: 0.2-2.9) and 3.8 (standard deviation: 3.0, range: 0.4-11.3) Gy, respectively. There was an inverse linear relationship (R2 = 0.52) between heart-to-lumpectomy cavity distance and mean heart equivalent dose in 2 Gy fractions. One patient (5%) experienced symptomatic cardiac toxicity. CONCLUSIONS: MC-APBI consistently delivers average doses to the heart and LAD that are similar to those achieved in most series with deep inspiration breath-hold and lower than free-breathing radiotherapy techniques. Distance from the heart to the lumpectomy cavity and the availability of other heart-sparing technologies should be considered to minimize the risk of cardiac toxicity.

Novel use of ViewRay MRI guidance for high-dose-rate brachytherapy in the treatment of cervical cancer.

PURPOSE: To characterize image quality and feasibility of using ViewRay MRI (VR)-guided brachytherapy planning for cervical cancer. METHODS AND MATERIALS: Cervical cancer patients receiving intracavitary brachytherapy with tandem and ovoids, planned using 0.35T VR MRI at our institution, were included in this series. The high-risk clinical target volume (HR-CTV), visible gross tumor volume, bladder, sigmoid, bowel, and rectum contours for each fraction of brachytherapy were evaluated for dosimetric parameters. Typically, five brachytherapy treatments were planned using the T2 sequence on diagnostic MRI for the first and third fractions, and a noncontrast true fast imaging with steady-state precession sequence on VR or CT scan for the remaining fractions. Most patients received 5.5 Gy × 5 fractions using high-dose-rate Ir-192 following 45 Gy of whole-pelvis radiotherapy. The plan was initiated at 5.5 Gy to point A and subsequently optimized and prescribed to the HR-CTV. The goal equivalent dose in 2 Gy fractions for the combined external beam and brachytherapy dose was 85 Gy. Soft-tissue visualization using contrast-to-noise ratios to distinguish normal tissues from tumor at their interface was compared between diagnostic MRI, CT, and VR. RESULTS: One hundred and forty-two fractions of intracavitary brachytherapy were performed from April 2015 to January 2017 on 29 cervical cancer patients, ranging from stages IB1 to IVA. The median HR-CTV was 27.78 cc, with median D90 HR-CTV of 6.1 Gy. The median time from instrument placement to start of treatment using VR was 65 min (scan time 2 min), compared to 105 min using diagnostic MRI (scan time 11 min) (t-test, p < 0.01). The contrast-to-noise ratio of tumor to cervix in both diagnostic MRI and VR had significantly higher values compared to CT (ANOVA and t-tests, p < 0.01). CONCLUSIONS: We report the first clinical use of VR-guided brachytherapy. Time to treatment using this approach was shorter compared to diagnostic MRI. VR also provided significant advantage in visualizing the tumor and cervix compared to CT. This presents a feasible and reliable manner to image and plan gynecologic brachytherapy.

Clinical implementation of a novel Double-Balloon single-entry breast brachytherapy applicator.

PURPOSE: The purpose of the study was to describe the clinical utilization of a novel Double-Balloon applicator for accelerated partial breast irradiation (APBI). METHODS AND MATERIALS: The Double-Balloon single-entry breast applicator contains a single central treatment catheter, as well as four peripheral catheters that can be differentially loaded to customize radiation dose coverage. An inner balloon is filled with up to 7-30 cm3 of saline to increase separation between the peripheral catheters, and an outer balloon is filled with up to 37-115 cm3 of saline to displace breast tissue from the peripheral catheters. Treatment planning objectives include coverage of the breast planning target volume to a minimum of V90 > 90%, limiting dose heterogeneity such that V200 < 10 cm3 and V150 < 50 cm3, and limiting maximum dose to skin (<100% of prescription dose) and ribs (<145% of prescription dose). RESULTS: High-dose-rate APBI was delivered to 11 women using this device (34 Gy in 10 twice daily fractions). The mean V90 was 98.2% (range 94.2-99.4%). The mean skin Dmax with the Double-Balloon applicator was 83.3% (range 75.6-99.5%). The mean breast V200 was 5.8 cm3 (range 2.3-10.2 cm3), and the mean breast V150 was 32.9 cm3 (range 25.0-41.7 cm3). Pretreatment quality assurance was performed using CT prior to each morning fraction and ultrasound prior to each afternoon fraction. CONCLUSIONS: The Double-Balloon applicator can be easily introduced into a previously existing brachytherapy program. APBI plans created with this applicator achieve excellent planning target volume coverage, while limiting skin dose and maintaining breast V200 < 10 cm3.

Simulation study of high-dose-rate brachytherapy for early glottic cancer.

PURPOSE: External beam radiation therapy (EBRT) is effective for early glottic cancers, with cure rates of ∼90% for T1 tumors. EBRT has strengths but also disadvantages including radiation to healthy tissues and duration of 5-7 weeks. With advances in laryngeal framework surgery, new devices can provide reliable, minimally invasive access to the larynx. Such devices could be modified to insert brachytherapy catheters. Brachytherapy could provide focused radiation while limiting dose to normal structures in the larynx and neck. As a preliminary step, we performed simulations comparing EBRT to high-dose-rate brachytherapy to assess if this approach could provide dosimetric advantage. METHODS AND MATERIALS: One- and 2-catheter brachytherapy simulations were performed for 3 patients with T1 glottic carcinoma. Percentage of dose delivered to the target and adjacent structures was compared with conventional EBRT using 3D and intensity-modulated radiation therapy approaches. RESULTS: Percentage of structures exposed to 50% of the dose was lower for brachytherapy compared with 3D EBRT and intensity-modulated radiation therapy, particularly for the cricoid and contralateral arytenoid. Dose was also lower for the carotid-internal jugular vein complexes compared with 3D EBRT. Dose profiles did not differ significantly between 1- and 2-catheter simulations. CONCLUSION: Brachytherapy can decrease radiation to normal tissues including laryngeal cartilages and carotid-internal jugular vein complexes. Recent advancements allowing catheter placement may afford the potential to decrease radiation to healthy tissues with decreased treatment time. However, careful, stepwise evaluation of feasibility and outcomes in model systems is required before recommending this approach for such high cure rate cancers in humans.

Essentials and guidelines for clinical medical physics residency training programs: executive summary of AAPM Report Number 249.

There is a clear need for established standards for medical physics residency training. The complexity of techniques in imaging, nuclear medicine, and radiation oncology continues to increase with each passing year. It is therefore imperative that training requirements and competencies are routinely reviewed and updated to reflect the changing environment in hospitals and clinics across the country. In 2010, the AAPM Work Group on Periodic Review of Medical Physics Residency Training was formed and charged with updating AAPM Report Number 90. This work group includes AAPM members with extensive experience in clinical, professional, and educational aspects of medical physics. The resulting report, AAPM Report Number 249, concentrates on the clinical and professional knowledge needed to function independently as a practicing medical physicist in the areas of radiation oncology, imaging, and nuclear medicine, and constitutes a revision to AAPM Report Number 90. This manuscript presents an executive summary of AAPM Report Number 249.

Cervical brachytherapy technique for locally advanced carcinoma of the cervix in a patient with septate uterus.

PURPOSE: To describe an approach to cervical brachytherapy in a patient with congenital septate uterus and locally advanced cervical carcinoma. MATERIAL AND METHODS: The patient is a 34-year-old female with septate uterus presenting with pelvic pain. Workup demonstrated a stage IIB cervical adenocarcinoma with imaging evidence of an involved right external iliac lymph node. The patient received whole pelvic radiation, with concurrent weekly cisplatin (40 mg/m(2)), to a dose of 45 Gy in 25 fractions followed by a parametrial boost of 5.4 Gy and an additional nodal boost of 9 Gy. RESULTS: The patient was initiated on cervical brachytherapy following fraction 23 of pelvic radiation. To conform to her septated uterus, a Rotte-Y tandem was used. Additionally, 2 CT-compatible ovoids were placed in the vaginal apex to enhance dose distribution and coverage of the target volume. Each fraction of brachytherapy was performed with CT-based planning. A high-risk clinical target volume (HR-CTV) and normal structures were defined and constrained per American Brachytherapy Society (ABS) and Groupe Européen de Curiethérapie/European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) guidelines. The brachytherapy dose was 27.5 Gy in 5 fractions of 5.5 Gy each, prescribed to the HR-CTV. CONCLUSIONS: Herein, we report the first documented case of cervical brachytherapy in a patient with septate uterus and locally advanced cervical carcinoma. Using CT-guided planning, in conjunction with the ABS and GEC-ESTRO guidelines, the patient was effectively treated with adapted cervical brachytherapy, meeting criteria for HR-CTV coverage and normal tissue tolerances.

Adjuvant and definitive radiation therapy for primary carcinoma of the vagina using brachytherapy and external beam radiation therapy.

PURPOSE: To report the outcomes of patients receiving vaginal brachytherapy and/or external beam radiation therapy (EBRT) for primary vaginal cancer. MATERIAL AND METHODS: Between 1983 and 2009, 63 patients received brachytherapy and/or EBRT for primary tumors of the vagina at a single tertiary center. Patient data was collected via chart review. The Kaplan-Meier method was used to calculate actuarial pelvic local control (LC), disease-free survival (DFS), overall survival (OS), and severe late toxicity rates. Acute and late toxicities were scored according to the Common Terminology Criteria for Adverse Events version 3 (CTCAE v3.0). RESULTS: Median follow up was 44.2 months. Patients with early stage disease (stages I and II) had significantly improved 5-year OS when compared to patients with locally advanced disease (stages III and IVA) (73.3 vs. 34.4%, p = 0.032). Patients with greater than 1/3 vaginal involvement had significantly worse prognosis than patients with tumors involving 1/3 or less of the vagina, with the later having superior DFS (84.0 vs. 52.4%, p = 0.007) and LC (86.9 vs. 60.4%, p = 0.018) at 5-years. Age, histology, and brachytherapy technique did not impact treatment outcomes. The 5-year actuarial grade 3 or higher toxicity rate was 23.1% (95% CI: 10.6-35.6%). Concurrent chemotherapy had no impact on outcomes or toxicity in this analysis. CONCLUSIONS: Success of treatment for vaginal cancer depends primarily on disease stage, but other contributing factors such as extent of vaginal involvement and tumor location significantly impact outcomes. Treatment of vaginal cancer with primary radiotherapy yields acceptable results with reasonable toxicity rates. Management of this rare malignancy requires a multidisciplinary approach to appropriately optimize therapy.

Locoregional recurrence following accelerated partial breast irradiation for early-stage invasive breast cancer: significance of estrogen receptor status and other pathological variables.

BACKGROUND: Understanding risk factors for locoregional recurrence (LRR) after accelerated partial breast irradiation (APBI) can help to guide patient selection for treatment with APBI. Published findings to date have not been consistent. More data are needed as these risk factors continue to be defined. METHODS: A total of 277 women with early-stage invasive breast cancer underwent lumpectomy and were treated adjuvantly at our institution with APBI using high-dose rate brachytherapy. APBI was delivered using multicatheter interstitial brachytherapy (91 %) or single-entry catheter brachytherapy (9 %) to a dose of 32-34 Gy in 8-10 twice daily fractions. Failure patterns and risk factors for recurrence were analyzed. RESULTS: With a median follow-up of 61 months, the 5-year locoregional control rate was 94.4 %. Negative estrogen receptor (ER) status was strongly associated with LRR on multivariate analysis (p < 0.005). Lobular histology, the presence of an extensive intraductal component, and lymphovascular invasion also were significant but to a lesser degree than ER-negative status. Patients with multiple risk factors were at highest risk for LRR. Age was not significantly associated with increased risk for LRR. CONCLUSIONS: The presence of specific pathological features, particularly ER negative status, was associated with increased risk of LRR in this cohort of women treated with APBI. Further investigation is warranted to determine whether patients with adverse pathological risk factors are at higher risk of LRR after APBI than after conventional whole breast irradiation (WBI), as these same features also may place women at risk for LRR after WBI.

Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: report of the AAPM and ESTRO.

PURPOSE: Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific (192)Ir, (137)Cs, and (60)Co source models. METHODS: This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parameter dependence on source active length. RESULTS: Consensus datasets for commercially available high-energy photon sources are provided, along with recommended methods for evaluating these datasets. Recommendations on dosimetry characterization methods, mainly using experimental procedures and Monte Carlo, are established and discussed. Also included are methodological recommendations on detector choice, detector energy response characterization and phantom materials, and measurement specification methodology. Uncertainty analyses are discussed and recommendations for high-energy sources without consensus datasets are given. CONCLUSIONS: Recommended consensus datasets for high-energy sources have been derived for sources that were commercially available as of January 2010. Data are presented according to the AAPM TG-43U1 formalism, with modified interpolation and extrapolation techniques of the AAPM TG-43U1S1 report for the 2D anisotropy function and radial dose function.

Outcomes after accelerated partial breast irradiation in patients with ASTRO consensus statement cautionary features.

PURPOSE: To evaluate outcomes among women with American Society for Radiation Oncology (ASTRO) consensus statement cautionary features treated with brachytherapy-based accelerated partial breast irradiation (APBI). METHODS AND MATERIALS: Between March 2001 and June 2006, 322 consecutive patients were treated with high-dose-rate (HDR) APBI at the University of Wisconsin. A total of 136 patients were identified who met the ASTRO cautionary criteria. Thirty-eight (27.9%) patients possessed multiple cautionary factors. All patients received 32 to 34 Gy in 8 to 10 twice-daily fractions using multicatheter (93.4%) or Mammosite balloon (6.6%) brachytherapy. RESULTS: With a median follow-up of 60 months, there were 5 ipsilateral breast tumor recurrences (IBTR), three local, and two loco-regional. The 5-year actuarial rate of IBTR was 4.8%±4.1%. The 5-year disease-free survival was 89.6%, with a cause-specific survival and overall survival of 97.6% and 95.3%, respectively. There were no IBTRs among 32 patients with ductal carcinoma in situ (DCIS) vs. 6.1% for patients with invasive carcinoma (p=0.24). Among 104 patients with Stage I or II invasive carcinoma, the IBTR rate for patients considered cautionary because of age alone was 0% vs. 12.7% in those deemed cautionary due to histopathologic factors (p=0.018). CONCLUSIONS: Overall, we observed few local recurrences among patients with cautionary features. Women with DCIS and patients 50 to 59 years of age with Stage I/II disease who otherwise meet the criteria for suitability appear to be at a low risk of IBTR. Patients with tumor-related cautionary features will benefit from careful patient selection.

American Society of Radiation Oncology recommendations for documenting intensity-modulated radiation therapy treatments.

Despite the widespread use of intensity-modulated radiation therapy (IMRT) for approximately a decade, a lack of adequate guidelines for documenting these treatments persists. Proper IMRT treatment documentation is necessary for accurate reconstruction of prior treatments when a patient presents with a marginal recurrence. This is especially crucial when the follow-up care is managed at a second treatment facility not involved in the initial IMRT treatment. To address this issue, an American Society for Radiation Oncology (ASTRO) workgroup within the American ASTRO Radiation Physics Committee was formed at the request of the ASTRO Research Council to develop a set of recommendations for documenting IMRT treatments. This document provides a set of comprehensive recommendations for documenting IMRT treatments, as well as image-guidance procedures, with example forms provided.

A dosimetric comparison of MammoSite and ClearPath high-dose-rate breast brachytherapy devices.

PURPOSE: A new form of partial breast irradiation (PBI), ClearPath (CP) breast brachytherapy, has been introduced. We present our results of a dosimetric comparison of MammoSite (MS) and CP PBI. METHODS AND MATERIALS: The dimensions of the CP device were reconstructed onto the MS planning CT scans for 15 previously treated patients. The mean %V(100), %V(150), %V(200) (percent of the PTV that received 100%, 150%, and 200% of the prescription dose, respectively), ipsilateral breast %V(50) (percent of the ipsilateral normal breast that received 50% of the prescription dose), ipsilateral lung %V(30) (percent of the ipsilateral lung that received 30% of the prescription dose), the heart %V(5) (percent of the heart that received 5% of the prescription dose), and the maximum skin point dose per fraction were then determined for each patient using the two methods of balloon-based PBI. RESULTS: The mean %V(100) was 96.5% vs. 96.5%, the mean %V(150) was 42.1% vs. 42.9% (p=ns), and the mean V(200) was 11.4% vs. 15.2% (p<.05) for the MS and CP methods, respectively. The mean ipsilateral breast %V(50) was 19.8% vs.18.0% (p<.05), the mean ipsilateral lung %V(30) was 3.7% vs. 2.8% (p<.05), the mean heart %V(5) was 57.0% vs. 54.3% (p<.05), and the maximum skin point dose per fraction was 312.2 and 273.6cGy (p<.05) for the MS and CP methods, respectively. CONCLUSIONS: The MS and CP methods of PBI offer comparable target volume coverage; however, the CP device achieves increased normal tissue sparing.

Multicatheter hybrid breast brachytherapy: a potential alternative for patients with inadequate skin distance.

PURPOSE: The purpose of this study was to determine whether the ClearPath (CP) multicatheter hybrid device was able to achieve acceptable dosimetry in patients in whom the proximity of the breast surgical cavity to the skin precluded treatment with intracavitary MammoSite (MS) brachytherapy. METHODS AND MATERIALS: The study consisted of 11 patients who had the MS catheter placed and who were subsequently not treated due to inadequate skin distance. A phantom scan of the CP multicatheter hybrid device was superimposed on the MS CT scan and a dosimetric comparison was performed. RESULTS: The median MS balloon size, diameter, and minimum skin distance were 40 cc, 4.1cm, and 5mm, respectively. The D(90), V(100), V(150), and V(200) with MS vs. CP were 95.29% vs. 97.06%, 88.8% vs. 91.3%, 35.7% vs. 38.0%, and 9.4% vs. 9.6%, respectively. The median maximum skin dose was 5.5 Gy vs. 3.9 Gy (p <.0001). The median dose homogeneity index (DHI) was 0.60 vs. 0.59 (p=.09). The median maximum rib, heart, and lung dose were 2.17 Gy vs. 2.18 Gy, 2.17 Gy vs. 2.18 Gy, and 0.50 Gy vs. 0.56 Gy, respectively. CONCLUSION: The hybrid CP catheter reduced the skin dose significantly without compromising the planning target volume coverage, DHI, or dose to other critical organs. The use of this device has the potential to increase the applicability of accelerated partial breast brachytherapy (APBI) in patients with a surgical cavity close to skin compared with balloon brachytherapy.

Clinical outcome analysis in "high-risk" versus "low-risk" patients eligible for national surgical adjuvant breast and bowel B-39/radiation therapy oncology group 0413 trial: five-year results.

PURPOSE: To report the local control and overall survival outcomes after lumpectomy followed by accelerated partial breast irradiation in high-risk patients as defined by the current inclusion criteria for the National Surgical Adjuvant Breast and Bowel B-39/Radiation Therapy Oncology Group 0413 Intergroup trial. METHODS AND MATERIALS: Between 2000 and 2005, 273 women with early-stage breast cancer were treated using either multicatheter interstitial brachytherapy (n=247) or MammoSite (n=26). Patients received 32-34 Gy in 8-10 twice-daily fractions using high-dose-rate 192Ir brachytherapy. All patients met the initial inclusion criteria for the Intergroup trial and were separated into two groups: high-risk patients (representing the cohort that remained eligible for the Intergroup trial) who satisfied one or more of the "high-risk" criteria (age<50 years, estrogen receptor negative, and/or positive lymph nodes; n=90), and low-risk patients who comprised the remainder of the cohort (n=183). The outcomes of the two cohorts were analyzed and compared. RESULTS: The median follow-up of the entire cohort was 48.5 months. No significant difference was found in outcomes at 5 years between the low- and high-risk groups, with a local control rate of 97.8% vs. 93.6%, crude local recurrence rate of 2.2% (n=4) vs. 4.4% (n=4), and overall survival rate of 92.1% vs. 89.5%, respectively. CONCLUSION: At 5 years, no statistically significant difference was found in outcomes for patients deemed to be at greater risk in the current National Surgical Adjuvant Breast and Bowel B-39/Radiation Therapy Oncology Group 0413 Intergroup trial. These clinical data support the inclusion of this "high-risk" population in this important ongoing study.

A dosimetric comparison of accelerated partial breast irradiation techniques: multicatheter interstitial brachytherapy, three-dimensional conformal radiotherapy, and supine versus prone helical tomotherapy.

PURPOSE: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. METHODS AND MATERIALS: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD(mean)) values were compared. RESULTS: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value <0.05. The mean V100 was significantly lower for IB (12% vs. 15% for PT, 18% for ST, and 26% for 3D-CRT). A greater significant differential was seen when comparing V50 with mean values of 24%, 43%, 47%, and 52% for IB, PT, ST, and 3D-CRT, respectively. The IB and PT were similar and delivered an average lung NTD(mean) dose of 1.3 Gy(3) and 1.2 Gy(3), respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. CONCLUSIONS: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals.

Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 kev.

This paper presents the recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Therapeutic Radiology and Oncology (ESTRO) on the dosimetric parameters to be characterized, and dosimetric studies to be performed to obtain them, for brachytherapy sources with average energy higher than 50 keV that are intended for routine clinical use. In addition, this document makes recommendations on procedures to be used to maintain vendor source strength calibration accuracy. These recommendations reflect the guidance of the AAPM and the ESTRO for its members, and may also be used as guidance to vendors and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.

Image-guided breast brachytherapy: an alternative to whole-breast radiotherapy.

Lumpectomy and whole-breast radiotherapy (ie, breast-conservation treatment) are accepted as viable alternatives to mastectomy in locoregional management of breast cancer. These techniques are used to keep morbidity to a minimum, optimise cosmesis, and maintain treatment outcomes. Pathological and clinical data suggest that most recurrences of cancer in the ipsilateral breast are in the vicinity of the index lesion, and that remote recurrences are uncommon, whether or not whole-breast radiotherapy is delivered. These data lend support to the idea of partial-breast radiotherapy. Such a restricted treatment volume allows safe delivery of an accelerated hypofractionated regimen over a shortened course of 1 week. This technique differs from that of standard whole-breast tangential external-beam radiotherapy and necessitates investigation of accelerated partial-breast irradiation (APBI). Several techniques of APBI are being investigated; however, most experience, and the most favourable early outcomes, has been obtained with image-guided breast brachytherapy. This review highlights the rationale and outcomes of brachytherapy techniques.