Radiation-Induced Complications after Breast Cancer Radiation Therapy: a Pictorial Review of Multimodality Imaging Findings

The purpose of this pictorial essay is to illustrate the multimodality imaging findings of a wide spectrum of radiation-induced complications of breast cancer in the sequence of occurrence. We have classified radiation-induced complications into three groups based on the time sequence of occurrence. Knowledge of these findings will allow for the early detection of complications as well as the ability to differentiate tumor recurrence.     

Automatic Generation of a Plan Optimization Volume for Tangential Field Breast Cancer Radiation Therapy

Background and Purpose: Dose homogeneity is one of the objectives during computer planning of postoperative radiotherapy of the conserved breast. For three-dimensional (3-D) optimization of the dose distribution using serial CT scan images, suitable volumes have to be delineated. The purpose of this study was to develop a computer-generated delineation of a plan optimization volume (POV) and an irradiated volume (IV) and to automate their use in a fast dose homogeneity optimization engine. Patients and Methods: Simulation was performed according to our standard procedure which involves the positioning of a lead collar around the palpable breast to facilitate the definition of gantry angle, collimator angle and field aperture for tangential wedged photon beams. In a change to the standard procedure an anterolateral radiograph was taken with its axis orthogonal to the central plane of the two tangential half-beams. Images from a serial CT scan were acquired in treatment position, and the geometric data of the three simulated beams were used by a computer program to generate the POV and IV. For each patient, weights of wedged and unwedged beams were optimized by either human heuristics using only the central slice (2-D), the whole set of CT slices (3-D), or by a computer algorithm using the POV, IV and lung volume with constrained matrix inversion (CMI) as optimization method. The resulting dose distributions were compared. Results: The total planning procedure took, on average, 44 min of which < 7 min were needed for human interactions, compared to about 52 min for the standard planning at Ghent University Hospital, Belgium. The simulation time is increased by 2–3 min. The method provides 3-D information of the dose distribution. Dose homogeneity and minimum dose inside the POV and maximum dose inside the IV were not significantly different for the three optimization techniques. Conclusion: This automated planning method is capable of replacing the contouring of the clinical target volume as well as the trial-and-error procedure of assigning weights of wedged and unwedged beams by an experienced planner.     

Clinical Implementation of Tangential Field Intensity Modulated Radiation Therapy (IMRT) Using Sliding Window Technique and Dosimetric Comparison with 3D Conformal Therapy (3DCRT) in Breast Cancer

The purpose of this study was to evaluate the clinical implementation of tangential field IMRT using sliding window technique and to compare dosimetric parameters with 3-dimensional conformal radiation therapy (3DCRT). Twenty breast cancer patients were randomly selected for comparison of intensity modulated radiation therapy (IMRT)-based treatment plan with 3DCRT. Inverse treatment was performed using the sliding window technique, employing the Eclipse^® Planning System (version 7.1.59, Varian, Palo Alto, CA). The dosimetric parameters compared were V₉₅ (the percentage of target volume getting ≥95% of prescribed dose), V₁₀₅, V₁₁₀, and dose homogeneity index, DHI (percentage of target volume getting between 95% and 110% of prescribed dose). The mean V₉₅, DHI, V₁₀₅, and V₁₁₀ for target volume for IMRT vs. 3D were 90.6% (standard deviation [SD]: 3.2) vs. 91% (SD: 3.0), 87.7 (SD: 6.0) vs. 82.6 (SD: 7.8), 27.3% (SD: 20.3) vs. 49.4% (SD: 14.3), and 2.8 (SD: 5.6) vs. 8.4% (SD: 7.4), respectively. DHI was increased by 6.3% with IMRT compared to 3DCRT (p < 0.05). The reductions of V₁₀₅ and V₁₁₀ for the IMRT compared to 3DCRT were 44.7% and 66.3%, respectively (p < 0.01). The mean dose and V₃₀ for heart with IMRT were 2.3 (SD: 1.1) and 1.05 (SD: 1.5) respectively, which was a reduction by 6.8% and 7.9%, respectively, in comparison with 3D. Similarly, the mean dose and V₂₀ for the ipsilateral lung and the percentage of volume of contralateral volume lung receiving > 5% of prescribed dose with IMRT were reduced by 9.9%, 2.2%, and 35%, respectively. The mean of total monitor units used for IMRT and 3DCRT was about the same (397 vs. 387). The tangential field IMRT for intact breast using sliding window technique was successfully implemented in the clinic. We have now treated more than 1000 breast cancer patients with this technique. The dosimetric data suggest improved dose homogeneity in the breast and reduction in the dose to lung and heart for IMRT treatments, which may be of clinical value in potentially contributing to improved cosmetic results and reduced late treatment-related toxicity.     

Clinical Implementation of Tangential Field Intensity Modulated Radiation Therapy (IMRT) Using Sliding Window Technique and Dosimetric Comparison with 3D Conformal Therapy (3DCRT) in Breast Cancer

The purpose of this study was to evaluate the clinical implementation of tangential field IMRT using sliding window technique and to compare dosimetric parameters with 3-dimensional conformal radiation therapy (3DCRT). Twenty breast cancer patients were randomly selected for comparison of intensity modulated radiation therapy (IMRT)-based treatment plan with 3DCRT. Inverse treatment was performed using the sliding window technique, employing the Eclipse^® Planning System (version 7.1.59, Varian, Palo Alto, CA). The dosimetric parameters compared were V₉₅ (the percentage of target volume getting ≥95% of prescribed dose), V₁₀₅, V₁₁₀, and dose homogeneity index, DHI (percentage of target volume getting between 95% and 110% of prescribed dose). The mean V₉₅, DHI, V₁₀₅, and V₁₁₀ for target volume for IMRT vs. 3D were 90.6% (standard deviation [SD]: 3.2) vs. 91% (SD: 3.0), 87.7 (SD: 6.0) vs. 82.6 (SD: 7.8), 27.3% (SD: 20.3) vs. 49.4% (SD: 14.3), and 2.8 (SD: 5.6) vs. 8.4% (SD: 7.4), respectively. DHI was increased by 6.3% with IMRT compared to 3DCRT (p < 0.05). The reductions of V₁₀₅ and V₁₁₀ for the IMRT compared to 3DCRT were 44.7% and 66.3%, respectively (p < 0.01). The mean dose and V₃₀ for heart with IMRT were 2.3 (SD: 1.1) and 1.05 (SD: 1.5) respectively, which was a reduction by 6.8% and 7.9%, respectively, in comparison with 3D. Similarly, the mean dose and V₂₀ for the ipsilateral lung and the percentage of volume of contralateral volume lung receiving > 5% of prescribed dose with IMRT were reduced by 9.9%, 2.2%, and 35%, respectively. The mean of total monitor units used for IMRT and 3DCRT was about the same (397 vs. 387). The tangential field IMRT for intact breast using sliding window technique was successfully implemented in the clinic. We have now treated more than 1000 breast cancer patients with this technique. The dosimetric data suggest improved dose homogeneity in the breast and reduction in the dose to lung and heart for IMRT treatments, which may be of clinical value in potentially contributing to improved cosmetic results and reduced late treatment-related toxicity.     

Comparison of heart dose in early-stage left-sided breast cancers treated with intraoperative radiation therapy or whole-breast irradiation with deep inspiratory breath hold

PURPOSETo compare heart dose between patients treated with lumpectomy and either intraoperative radiation therapy (IORT) with CT-guided high-dose-rate brachytherapy (precision breast IORT [PB-IORT]) or whole-breast irradiation with deep inspiratory breath hold (WBI-DIBH) for early-stage left-sided breast cancers.METHODS AND MATERIALSWe retrospectively identified the 17 patients with left-sided breast cancers treated with PB-IORT on a phase I clinical trial and 17 patients with left-sided tumors who had undergone lumpectomy and adjuvant WBI-DIBH. Dosimetric data were obtained. T-testing was performed and biologically effective doses (BEDs) were calculated using an α/β ratio of 2 Gy.ResultsMean heart dose was significantly lower with WBI-DIBH compared with PB-IORT (0.61 vs. 0.87 Gy, p = 0.006). Mean heart BED was lower with WBI-DIBH (0.62 vs. 1.3 Gy₂, p = 0.0001). Nominal maximum heart dose was higher with WBI-DIBH (11.37 vs. 4.81 Gy, p = 0.004). Maximum heart dose BED was similar between WBI-DIBH and IORT, 16.63 vs. 19.36 Gy (p = 0.64), respectively. No difference was found in mean left anterior descending artery dose: 2.18 Gy with WBI-DIBH and 1.89 Gy with IORT (p = 0.446). The maximum left anterior descending doses were 9.63 Gy and 3.62 Gy with WBI-DIBH and IORT, respectively (p = 0.016). Distance from the heart to the lumpectomy cavity was inversely associated with heart dose for PB-IORT, but not for WBI-IORT.CONCLUSIONSHeart doses were low in both groups. Expected increase in cardiac risk at these doses is minimal. It is unlikely that there will be a clinically significant difference in cardiac toxicity in patients treated with WBI-DIBH or PB-IORT. Further research is needed to evaluate the actual clinical impact of the observed cardiac doses delivered with these modalities.     

单侧乳腺癌放疗中健侧乳腺受照剂量及其诱发癌症风险预测

目的 分析单侧乳腺癌放疗所致健侧乳腺的剂量,并估算放疗诱发健侧乳腺癌的风险。方法 在同一医院调查49例接受单侧乳腺放疗患者的基本情况,从治疗计划系统上获取其健侧乳腺的辐射剂量并进行统计分析;利用美国电离辐射生物效应委员会报告Ⅶ第2部分（BEIR Ⅶ phase 2）推荐的风险模型,结合我国人口寿命表,预测不同年龄段单侧乳腺癌患者接受放疗诱发健侧乳腺癌的风险。结果 患者的处方剂量均为50 Gy,健侧乳腺的平均剂量为（1.21±0.89）Gy （0.14~3.59 Gy）,最大点剂量平均为（17.42±13.20）Gy （0.98~45.27 Gy）;健侧乳腺的最大点剂量和平均剂量变化幅度大,且有显著相关性（R=0.527,P=0.000）,不同年龄段患者的健侧乳腺平均剂量差异无统计学意义（P>0.05）。基于健侧乳腺的平均剂量,估算出受照年龄为35、40、50、60、70和80岁患者的健侧乳腺癌终生归因风险分别为2 449/10万人、1 857/10万人、994/10万人、446/10万人、173/10万人和55/10万人。结论 患者接受单侧乳腺癌放疗过程中,其健侧乳腺剂量可达1 Gy水平,可能增加健侧乳腺癌发生风险对年轻患者不容忽视,在制定放射治疗计划时应尽可能控制对患者健侧乳腺的照射。     

Using Artificial Intelligence to Improve the Quality and Safety of Radiation Therapy

Within artificial intelligence, machine learning (ML) efforts in radiation oncology have augmented the transition from generalized to personalized treatment delivery. Although their impact on quality and safety of radiation therapy has been limited, they are increasingly being used throughout radiation therapy workflows. Various data-driven approaches have been used for outcome prediction, CT simulation, clinical decision support, knowledge-based planning, adaptive radiation therapy, plan validation, machine quality assurance, and process quality assurance; however, there are many challenges that need to be addressed with the creation and usage of ML algorithms as well as the interpretation and dissemination of findings. In this review, the authors present current applications of ML in radiation oncology quality and safety initiatives, discuss challenges faced by the radiation oncology community, and suggest future directions.     

Radiation Dose Reduction of Chest CT with Iterative Reconstruction in Image Space - Part II: Assessment of Radiologists' Preferences Using Dual Source CT

Objective

To evaluate the impact of radiation dose and reconstruction algorithms on radiologists'' preferences, and whether an iterative reconstruction in image space (IRIS) can be used for dose reduction in chest CT.

Materials and Methods

Standard dose chest CT (SDCT) in 50 patients and low dose chest CT (LDCT) in another 50 patients were performed, using a dual-source CT, with 120 kVp and same reference mAs (50 mAs for SDCT and 25 mAs for LDCT) employed to both tubes by modifying the dual-energy scan mode. Full-dose data were obtained by combining the data from both tubes and half-dose data were separated from one tube. These were reconstructed by using a filtered back projection (FBP) and IRIS: full-dose FBP (F-FBP); full-dose IRIS (F-IRIS); half-dose FBP (H-FBP) and half-dose IRIS (H-IRIS). Ten H-IRIS/F-IRIS, 10 H-FBP/H-IRIS, 40 F-FBP/F-IRIS and 40 F-FBP/H-IRIS pairs of each SDCT and LDCT were randomized. The preference for clinical usage was determined by two radiologists with a 5-point-scale system for the followings: noise, contrast, and sharpness of mediastinum and lung.

Results

Radiologists preferred IRIS over FBP images in the same radiation dose for the evaluation of the lungs in both SDCT (p = 0.035) and LDCT (p < 0.001). When comparing between H-IRIS and F-IRIS, decreased radiation resulted in decreased preference. Observers preferred H-IRIS over F-FBP for the lungs in both SDCT and LDCT, even with reduced radiation dose by half in IRIS image (p < 0.05).

Conclusion

Radiologists'' preference may be influenced by both radiation dose and reconstruction algorithm. According to our preliminary results, dose reduction at 50% with IRIS may be feasible for lung parenchymal evaluation.     

湿润烧伤膏防治乳腺癌改良根治术后放射性皮肤损伤疗效观察

目的探讨湿润烧伤膏防治乳腺癌改良根治术后放射治疗所致放射性皮肤损伤的临床疗效。方法按照随机数表法将2014年8月至2018年8月沂水县人民医院及临沂市第三人民医院收治的拟采用放射治疗的乳腺癌改良根治术后患者随机分为观察组(60例)与对照组(60例),其中观察组患者于放射治疗后在放射部位预防性应用湿润烧伤膏,对照组患者放射治疗后不采取任何防护措施,对比观察两组患者放射部位皮肤损伤程度、皮肤损伤出现时间及放射治疗中断情况等。结果放射治疗20、40 Gy及疗程结束后,观察组患者皮肤损伤程度均明显低于对照组,两组对比,P均0.01,差异具有统计学意义;观察组患者皮肤损伤出现时间为(30. 80±1.40) d,明显晚于对照组患者皮肤损伤出现时间(16. 60±1.80) d,两组对比,P 0.01,差异具有统计学意义;治疗过程中,观察组患者中无1例患者中断治疗,对照组患者中14例患者中断治疗,两组对比,P0.01,差异具有统计学意义。结论湿润烧伤膏可有效减轻乳腺癌改良根治术后放射治疗所致放射性皮肤损伤的损伤程度,延缓皮肤损伤出现时间,疗效显著,且操作简便,值得临床推广应用。     

Radiation Dose Reduction of Chest CT with Iterative Reconstruction in Image Space - Part I: Studies on Image Quality Using Dual Source CT

Objective

To determine whether the image quality (IQ) is improved with iterative reconstruction in image space (IRIS), and whether IRIS can be used for radiation reduction in chest CT.

Materials and Methods

Standard dose chest CT (SDCT) in 50 patients and low dose chest CT (LDCT) in another 50 patients were performed, using a dual-source CT, with 120 kVp and same reference mAs (50 mAs for SDCT and 25 mAs for LDCT) employed to both tubes by modifying a dual-energy scan mode. Full-dose data were obtained by combining the data from both tubes and half-dose data were separated from a single tube. These were reconstructed by using a filtered back projection (FBP) and IRIS: full-dose FBP (F-FBP); full-dose IRIS (F-IRIS); half-dose FBP (H-FBP) and half-dose IRIS (H-IRIS). Objective noise was measured. The subjective IQ was evaluated by radiologists for the followings: noise, contrast and sharpness of mediastinum and lung.

Results

Objective noise was significantly lower in H-IRIS than in F-FBP (p < 0.01). In both SDCT and LDCT, the IQ scores were highest in F-IRIS, followed by F-FBP, H-IRIS and H-FBP, except those for sharpness of mediastinum, which tended to be higher in FBP. When comparing CT images between the same dose and different reconstruction (F-IRIS/F-FBP and H-IRIS/H-FBP) algorithms, scores tended to be higher in IRIS than in FBP, being more distinct in half-dose images. However, despite the use of IRIS, the scores were lower in H-IRIS than in F-FBP.

Conclusion

IRIS generally helps improve the IQ, being more distinct at the reduced radiation. However, reduced radiation by half results in IQ decrease even when using IRIS in chest CT.     

肝细胞肝癌心膈角或膈上淋巴结转移放疗疗效及预后因素分析

目的 研究肝细胞肝癌（HCC）患者心膈角或膈上淋巴结转移（LNM）放疗的疗效和预后因素。方法 回顾性分析复旦大学附属中山医院2010年1月至2020年8月56例心膈角或膈上LNM的HCC患者病例资料。按1月是否接受外照射分为外照射组和非外照射组,每组28例。外照射组放射野包括或不包括原发灶,非外照射组未给予任何针对心膈角或膈上LNM的局部治疗。比较两组的缓解率、生存率、局部控制率、预后因素。结果 外照射后部分缓解和完全缓解的患者分别为9例（32.1%）和9例（32.1%）。中位生存外照射组为16.1个月（95%CI 9.00~23.21,RR=3.63）,非外照射组为6.9个月（95%CI 4.63~8.77,RR=1.06）,两组比较差异有统计学意义（χ²=15.53,P<0.05）。心膈角或膈上LNM 1年局部控制率,外照射组为37.0%,非外照射组为10.7%,差异有统计学意义（χ²=5.28,P<0.05）。确诊心膈角或膈上LNM后,3个月内甲胎蛋白（AFP）较外照射前升高,外照射组4例（14.3%）,非外照射组13例（46.4%）,两组比较差异有统计学意义（χ²=6.84,P<0.05）。多变量分析结果显示,同时伴有肝内肿瘤多发、肝内肿瘤>5 cm、AFP≥400 μg/L、未行外照射者预后差。结论 心膈角或膈上LNM的HCC患者行外照射能延长总生存、提高LNM局部控制率。伴有肝内肿瘤多发、肝内肿瘤>5 cm、AFP≥400 μg/L、未行外照射者预后差。     

Long-term outcomes of APBI via multicatheter interstitial HDR brachytherapy: Results of a prospective single-institutional registry

PurposeLong-term outcome reports of accelerated partial-breast irradiation (APBI) are limited. Here, we report the 10-year outcomes of APBI delivered using multicatheter interstitial implant (ISI) brachytherapy.Methods and materialsPatients with early-stage breast cancer treated with APBI via ISI brachytherapy were enrolled in a prospective registry. Selection criteria included age ≥40 years, ductal carcinoma in situ or invasive tumor ≤3 cm, negative margins (≥2 mm), and negative axillary nodes. 34 Gy in 10 twice-daily fractions was administered to 2 cm of breast tissue surrounding the surgical bed. Toxicity and cosmetic outcomes were collected prospectively.ResultsA total of 175 patients were included. The median followup time was 10.0 years. Ten-year ipsilateral breast tumor control, regional control, freedom from distant metastasis, breast cancer–specific survival, and overall survival were 92.1%, 96.9%, 97.4%, 97.1%, and 81.2%, respectively. High-grade disease was correlated with increase in the rate of ipsilateral breast tumor recurrence. Grade 1 or 2 skin toxicity was present in 44 patients, and Grade 3 skin toxicity was present in only 1 patient. There were no Grade 4 or higher toxicities observed. Thirty-seven patients developed fat necrosis. Dose Homogeneity Index of ≤0.85 and integrated reference air-kerma of >3400 cGycm²/h correlated with higher rates of fat necrosis. There were 115 (66%), 51 (29%), 8 (5%), and 0 (0%) patients having excellent, good, fair, and poor cosmetic outcomes, respectively.ConclusionsAPBI using ISI brachytherapy offers excellent clinical outcomes in appropriately selected patients with excellent cosmetic outcomes and low rates of toxicities such as symptomatic fat necrosis.     

Toxicity and cosmetic outcomes after treatment with a novel form of breast IORT

PurposeIntraoperative radiation therapy (IORT), a form of accelerated partial breast irradiation (APBI), is an appealing alternative to postoperative whole breast irradiation for early-stage breast cancer. The purpose of this study was to examine the toxicity and cosmetic outcomes of patients treated with a novel form of breast IORT (precision breast IORT; PB-IORT), that delivers a targeted, higher dose of radiation than conventional IORT.Methods and MaterialsThe first 204 patients treated with PB-IORT in a Phase II clinical trial (NCT02400658) with 12 months of followup were included. Trial inclusion criteria were age ≥45 years, invasive or in situ breast cancer, tumor size ≤3 cm, and node negative. Toxicity and cosmetic scoring were performed at 6 and 12 months.Results98 patients (48%; 95% CI, 41–55%) experienced toxicity. Seven Grade 3 toxicities occurred (3.4%; 95% CI, 1.4–6.9%). Most patients (95%) had excellent or good cosmetic outcomes (95% CI, 91–98%) at 12 months. Most patients (94%) had little or no pigmentation change (95% CI, 90–97%), 88% little to no size change (95% CI, 82–92%), and 87% experienced minimal shape change (95% CI, 82–92%).ConclusionsOverall, Grade 3+ toxicity was rare and cosmetic outcomes were excellent. Severe toxicity with PB-IORT is similar to that reported in the TARGIT trial (3.3% rate of major toxicity) but lower than APBI (NSABP-39, 10.1% Grade 3/4 toxicities). We propose that the toxicity of PB-IORT compared with TARGIT and NSABP-39 is related to the radiation dose and delivery schedule. PB-IORT offers low-toxicity and good cosmetic outcomes when compared with other forms of APBI.     

First report on the feasibility of a permanently implantable uni-directional planar low dose rate brachytherapy sheet for patients with resectable or borderline resectable pancreatic cancer

BackgroundMargin negative resection in pancreatic cancer remains the only curative option but is challenging, especially with the retroperitoneal margin. Intraoperative radiation therapy (IORT) can improve rates of local control but requires specially designed facilities and equipment. This retrospective review describes initial results of a novel implantable mesh of uni-directional low dose rate (LDR) Pd-103 sources (sheet) used to deliver a focal margin-directed high-dose boost in patients with concern for close or positive margins.MethodsEleven consecutive patients from a single institution with resectable or borderline resectable pancreatic cancer with concern for positive margins were selected for sheet placement and retrospectively reviewed. Procedural outcomes, including the time to implant the device and complications, and clinical outcomes, including survival and patterns of failure, are reported. A dosimetric comparison of the LDR sheet with hypothetical stereotactic body radiotherapy (SBRT) boost is reported.ResultsOne patient had a resectable disease, and 10 patients had a borderline resectable disease and underwent neoadjuvant treatment. Sheet placement added 15 min to procedural time with no procedural or sheet-related complications. At a median follow up of 13 months, 64% (n = 7) of patients are alive and 55% (n = 6) are disease-free. Compared to a hypothetical SBRT boost, the LDR sheet delivered a negligible dose to kidneys, liver, and spinal cord with a 50% reduction in max dose to the small bowel.ConclusionThis is the first report of the use of an implantable uni-directional LDR brachytherapy sheet in patients with resected pancreatic cancer with concern for margin clearance, with no associated toxicity and favorable clinical outcomes.     

Time-driven activity-based costing of a novel form of CT-guided high-dose-rate brachytherapy intraoperative radiation therapy compared with conventional breast intraoperative radiation therapy for early stage breast cancer

IntroductionIntraoperative radiation therapy is an emerging option for adjuvant therapy for early stage breast cancer, although it is not currently considered standard of care in the United States. We applied time-driven activity-based costing to compare two alternative methods of breast intraoperative radiation therapy, including treatment similar to the techniques employed in the TARGIT-A clinical trial and a novel version with CT-guidance and high-dose-rate (HRD) brachytherapy.Methods and MaterialsProcess maps were created to describe the steps required to deliver intraoperative radiation therapy for early stage breast cancer at each institution. The components of intraoperative radiation therapy included personnel, equipment, and consumable supplies. The capacity cost rate was determined for each resource. Based on this, the delivery costs were calculated for each regimen. For comparison across centers, we did not account for indirect facilities costs and interinstitutional differences in personnel salaries.ResultsThe CT-guided, HRD form of intraoperative radiation therapy costs more to deliver ($4,126.21) than the conventional method studied in the TARGIT-A trial ($1,070.45). The cost of the brachytherapy balloon applicator ($2,750) was the primary driver of the estimated differences in costs. Consumable supplies were the largest contributor to the brachytherapy-based approach, whereas personnel costs were the largest contributor to costs of the standard form of intraoperative radiation therapy.ConclusionsWhen compared with the more established method of intraoperative radiation therapy using a portable superficial photon unit, the delivery of treatment with CT guidance and HDR brachytherapy is associated with substantially higher costs. The excess costs are driven primarily by the cost of the disposable brachytherapy balloon applicator and, to a lesser extent, additional personnel costs. Future work should include evaluation of a less expensive brachytherapy applicator to increase the anticipated value of brachytherapy-based intraoperative radiation therapy.     

Prostate-specific antigen doubling time is a significant predictor of overall and disease-free survival in patients with prostate adenocarcinoma treated with brachytherapy

PurposeRecently, new approaches have been implemented in treating patients with newly diagnosed metastatic prostate cancer (PCa). An interesting area of study is to determine which risk factors may be used as predictors of more aggressive PCa behavior in patients with biochemical failure. The aim of this study was to determine prognostic factors in patients with prostate-specific antigen (PSA) failure after undergoing brachytherapy.Methods and MaterialsBetween 1990 and 2015, 2771 patients with localized PCa underwent treatment at our institution treated by a single radiation oncologist with low-dose-rate brachytherapy as a component of definitive radiation therapy. Disease-specific survival (DSS), distant metastases (DM), and overall survival were calculated by the Kaplan–Meier method. Multivariable Cox regression analysis was also performed.ResultsIn this group, 2126 patients (89%) had no evidence of PSA failure. Of the 251 of patients that did have biochemical failure, 115 (45.8%), 58 (23.1%), 78 (31.1%) had a PSA doubling time (PSADT) of <6 months, 6–12 months, and >12 months, respectively. Doubling time was associated with a statistically significant impact on DSS and DM but not overall survival, which appears to be dominated by initial age at diagnosis as well as stage.ConclusionsWe have shown here that PSADT predicts for DSS and freedom from DM in our large prospectively followed cohort. Given the variable trajectory of metastatic and recurrent PCa, strong prognostic factors such as PSADT may be able to select a group of patients who benefit from earlier or escalated systemic therapies such as androgen deprivation or cytotoxic chemotherapy.     

Sensitivity of a Direct Computer-aided Detection System in Full-field Digital Mammography for Detection of Microcalcifications Not Associated with Mass or Architectural Distortion

Purpose

The purpose of this study was to evaluate the sensitivity of a direct computer-aided detection (CAD) system (d-CAD) in full-field digital mammography (FFDM) for the detection of microcalcifications not associated with mass or architectural distortion.

Materials and Methods

A database search of 1063 consecutive stereotactic core biopsies performed between 2002 and 2005 identified 196 patients with Breast Imaging-Reporting and Data System (BI-RADS) 4 and 5 microcalcifications not associated with mass or distortion detected exclusively by bilateral FFDM. A commercially available CAD system (Second Look, version 7.2) was retrospectively applied to the craniocaudal and mediolateral oblique views in these patients (mean age, 59 years; range, 35–84 years). Breast density, location and mammographic size of the lesion, distribution, and tumour histology were recorded and analysed by using χ², Fisher exact, or McNemar tests, when applicable.

Results

When using d-CAD, 71 of 74 malignant microcalcification cases (96%) and 101 of 122 benign microcalcifications (83%) were identified. There was a significant difference (P < .05) between CAD sensitivity on the craniocaudal view, 91% (68 of 75), vs CAD sensitivity on the mediolateral oblique view, 80% (60 of 75). The d-CAD sensitivity for dense breast tissue (American College of Radiology [ACR] density 3 and 4) was higher (97%) than d-CAD sensitivity (95%) for nondense tissue (ACR density 1 and 2), but the difference was not statically significant. All 28 malignant calcifications larger than 10 mm were detected by CAD, whereas the sensitivity for lesions small than or equal to 10 mm was 94%.

Conclusions

D-CAD had a high sensitivity in the depiction of asymptomatic breast cancers, which were seen as microcalcifications on FFDM screening, with a sensitivity of d-CAD on the craniocaudal view being significantly better. All malignant microcalcifications larger than 10 mm were detected by d-CAD.     

Efficacy and Radiation Exposure of Ultra-Low-Dose Chest CT at 100 kVp with Tin Filtration in CT-Guided Percutaneous Core Needle Biopsy for Small Pulmonary Lesions Using a Third-Generation Dual-Source CT Scanner

Purpose

To prospectively investigate efficacy and radiation dose of ultra-low-dose CT–guided percutaneous core needle biopsy (PCNB) at 100 kVp with tin filtration (¹⁰⁰Sn kVp) for small pulmonary lesions.