Executive summary of the American Radium Society® Appropriate Use Criteria for management of uterine carcinosarcoma.

OBJECTIVE: Uterine carcinosarcomas (UCS) represent a rare but aggressive subset of endometrial cancers, comprising <5% of uterine malignancies. To date, limited prospective trials exist from which evidence-based management of this rare malignancy can be developed. METHODS: The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines developed by a multidisciplinary expert panel for management of women with UCS. An extensive analysis of current medical literature from peer-reviewed journals was performed. A well-established methodology (modified Delphi) was used to rate the appropriate use of imaging and treatment procedures for the management of UCS. These guidelines are intended for the use of all practitioners who desire information about the management of UCS. RESULTS: The majority of patients with UCS will present with advanced extra uterine disease, with 10% presenting with metastatic disease. They have worse survival outcomes when compared to uterine high-grade endometrioid adenocarcinomas. The primary treatment for non-metastatic UCS is complete surgical staging with total hysterectomy, salpingo-oophorectomy and lymph node staging. Patients with UCS appear to benefit from adjuvant multimodality therapy to reduce the chance of tumor recurrence with the potential to improve overall survival. CONCLUSION: Women diagnosed with uterine UCS should undergo complete surgical staging. Adjuvant multimodality therapies should be considered in the treatment of both early- and advanced stage patients. Long-term surveillance is indicated as many of these women may recur. Prospective clinical studies of women with UCS are necessary for optimal management.

Evaluation of sparing organs at risk (OARs) in left-breast irradiation in the supine and prone positions and with deep inspiration breath-hold.

PURPOSE: To compare doses to organs at risk (OARs) for left-sided whole-breast radiation therapy with comparable planning target volume (PTV) coverage using three techniques: free breathing in a supine position (SFB), deep inspirational breath-hold in a supine position (SDIBH), and free breathing in prone position (PFB). MATERIALS AND METHODS: Thirty-three patients with left-sided early-stage breast cancer underwent CT simulation following SFB, SDIBH, and PFB protocols for whole-breast radiation therapy. One radiation oncologist contoured the breast PTV, heart, left ventricle (LV), and left anterior descending artery (LAD). Treatment plans were optimized using field-in-field technique with the AAA algorithm. Each plan was optimized to provide identical coverage to the PTV such that a reasonable comparison for OAR dosimetry could be evaluated. All plans were prescribed 42.56 Gy in 16 fractions to the left-breast PTV. RESULTS: The mean dose in SFB for the heart, LV, and LAD was 1.92, 3.19, and 21.73 Gy, respectively, which were significantly higher than the mean dose in SDIBH for the heart (1.08 Gy, P ≤ 0.0001), LV (1.50 Gy, P ≤ 0.0001), and LAD (6.3 Gy, P ≤ 0.0001) and in PFB for the heart (0.98 Gy, P ≤ 0.0001), LV (1.34 Gy, P ≤ 0.0001), and LAD (6.57 Gy, P ≤ 0.0001). Similar findings were noted for the cardiac components in SFB for V2.5, V5, V10, V20, and V30 compared with values in SDIBH and PFB. The mean dose for the left lung in PFB was 0.61 Gy that was significantly lower than in SFB (5.63 Gy, P ≤ 0.0001) and SDIBH (5.54 Gy, P ≤ 0.0001). Mean dose and dosimetric values for each OAR increased in SFB and SDIBH for patients with a large breast volume compared with values for patients with a small breast volume. CONCLUSIONS: SFB results in higher heart, LAD, and LV doses than the other techniques. Both PFB and SDIBH are more advantageous for these OARs irrespective of breast volume. PFB results in significantly lower lung doses than SFB and SDIBH. PFB always provided better results than SFB for the heart, LV, LAD, and lung. This conclusion contrasts with some published studies concluding that the prone position has no benefit for heart sparing.

SPECT/CT image-based dosimetry for Yttrium-90 radionuclide therapy: Application to treatment response.

This work demonstrates the efficacy of voxel-based 90 Y microsphere dosimetry utilizing post-therapy SPECT/CT imaging and applies it to the prediction of treatment response for the management of patients with hepatocellular carcinoma (HCC). A 90 Y microsphere dosimetry navigator (RapidSphere) within a commercial platform (Velocity, Varian Medical Systems) was demonstrated for three microsphere cases that were imaged using optimized bremsstrahlung SPECT/CT. For each case, the 90 Y SPECT/CT was registered to follow-up diagnostic MR/CT using deformable image registration. The voxel-based dose distribution was computed using the local deposition method with known injected activity. The system allowed the visualization of the isodose distributions on any of the registered image datasets and the calculation of dose-volume histograms (DVHs). The dosimetric analysis illustrated high local doses that are characteristic of blood-flow directed brachytherapy. In the first case, the HCC mass demonstrated a complete response to treatment indicated by a necrotic region in follow-up MR imaging. This result was dosimetrically predicted since the gross tumor volume (GTV) was well covered by the prescription isodose volume (V150 Gy = 85%). The second case illustrated a partial response to treatment which was characterized by incomplete necrosis of an HCC mass and a remaining area of solid enhancement in follow-up MR imaging. This result was predicted by dosimetric analysis because the GTV demonstrated incomplete coverage by the prescription isodose volume (V470 Gy = 18%). The third case demonstrated extrahepatic activity. The dosimetry indicated that the prescription (125 Gy) isodose region extended outside of the liver into the duodenum (178 Gy maximum dose). This was predictive of toxicity as the patient later developed a duodenal ulcer. The ability to predict outcomes and complications using deformable image registration, calculated isodose distributions, and DVHs, points to the clinical utility of patient-specific dose calculations for 90 Y radioembolization treatment planning.

Reproducibility of F18-FDG PET radiomic features for different cervical tumor segmentation methods, gray-level discretization, and reconstruction algorithms.

Site-specific investigations of the role of radiomics in cancer diagnosis and therapy are emerging. We evaluated the reproducibility of radiomic features extracted from 18 Flourine-fluorodeoxyglucose (18 F-FDG) PET images for three parameters: manual versus computer-aided segmentation methods, gray-level discretization, and PET image reconstruction algorithms. Our cohort consisted of pretreatment PET/CT scans from 88 cervical cancer patients. Two board-certified radiation oncologists manually segmented the metabolic tumor volume (MTV1 and MTV2 ) for each patient. For comparison, we used a graphical-based method to generate semiautomated segmented volumes (GBSV). To address any perturbations in radiomic feature values, we down-sampled the tumor volumes into three gray-levels: 32, 64, and 128 from the original gray-level of 256. Finally, we analyzed the effect on radiomic features on PET images of eight patients due to four PET 3D-reconstruction algorithms: maximum likelihood-ordered subset expectation maximization (OSEM) iterative reconstruction (IR) method, fourier rebinning-ML-OSEM (FOREIR), FORE-filtered back projection (FOREFBP), and 3D-Reprojection (3DRP) analytical method. We extracted 79 features from all segmentation method, gray-levels of down-sampled volumes, and PET reconstruction algorithms. The features were extracted using gray-level co-occurrence matrices (GLCM), gray-level size zone matrices (GLSZM), gray-level run-length matrices (GLRLM), neighborhood gray-tone difference matrices (NGTDM), shape-based features (SF), and intensity histogram features (IHF). We computed the Dice coefficient between each MTV and GBSV to measure segmentation accuracy. Coefficient values close to one indicate high agreement, and values close to zero indicate low agreement. We evaluated the effect on radiomic features by calculating the mean percentage differences (d¯) between feature values measured from each pair of parameter elements (i.e. segmentation methods: MTV1 -MTV2 , MTV1 -GBSV, MTV2 -GBSV; gray-levels: 64-32, 64-128, and 64-256; reconstruction algorithms: OSEM-FORE-OSEM, OSEM-FOREFBP, and OSEM-3DRP). We used |d¯| as a measure of radiomic feature reproducibility level, where any feature scored |d¯| ±SD ≤ |25|% ± 35% was considered reproducible. We used Bland-Altman analysis to evaluate the mean, standard deviation (SD), and upper/lower reproducibility limits (U/LRL) for radiomic features in response to variation in each testing parameter. Furthermore, we proposed U/LRL as a method to classify the level of reproducibility: High- ±1% ≤ U/LRL ≤ ±30%; Intermediate- ±30% < U/LRL ≤ ±45%; Low- ±45 < U/LRL ≤ ±50%. We considered any feature below the low level as nonreproducible (NR). Finally, we calculated the interclass correlation coefficient (ICC) to evaluate the reliability of radiomic feature measurements for each parameter. The segmented volumes of 65 patients (81.3%) scored Dice coefficient >0.75 for all three volumes. The result outcomes revealed a tendency of higher radiomic feature reproducibility among segmentation pair MTV1 -GBSV than MTV2 -GBSV, gray-level pairs of 64-32 and 64-128 than 64-256, and reconstruction algorithm pairs of OSEM-FOREIR and OSEM-FOREFBP than OSEM-3DRP. Although the choice of cervical tumor segmentation method, gray-level value, and reconstruction algorithm may affect radiomic features, some features were characterized by high reproducibility through all testing parameters. The number of radiomic features that showed insensitivity to variations in segmentation methods, gray-level discretization, and reconstruction algorithms was 10 (13%), 4 (5%), and 1 (1%), respectively. These results suggest that a careful analysis of the effects of these parameters is essential prior to any radiomics clinical application.

Clinical implications of a prostate-specific antigen bounce after radiation therapy for prostate cancer.

BACKGROUND: The objectives are to determine predictors of a prostate-specific antigen (PSA) bounce, whether a PSA bounce after radiotherapy for prostate cancer is associated with biochemical disease-free survival (bDFS), and the time course to a PSA bounce versus a biochemical failure post-irradiation. METHODS: Between July 2000 and December 2012, 691 prostate cancer patients without regional or distant metastases were treated with external beam radiation therapy and/or brachytherapy, and had at least 12 months of follow-up. A PSA bounce was defined as a temporary PSA increase of ≥ 0.4 ng/mL. bDFS was defined according to the nadir + 2 definition. RESULTS: The median follow-up was 42 months. The median time to first PSA bounce was 17 months (95% confidence interval 15-18 months). In contrast, the median time to biochemical failure was 41 months (95% confidence interval 28-53 months). Two hundred and twenty-six of 691 (33%) patients had at least one PSA bounce with a median magnitude of 1.0 ng/mL (range 0.4-17.0). A Gleason score of 6 (p < 0.0001) predicted a PSA bounce on multivariate analysis. Patients with a PSA bounce experienced improved bDFS on multivariate analysis (p = 0.002). CONCLUSIONS: Patients with a Gleason score of 6 were more likely to experience a PSA bounce which was associated with improved bDFS. A PSA bounce occurred sooner after radiotherapy than a biochemical failure. The authors recommend against performing prostate biopsies within 24-30 months of radiotherapy since an elevated PSA may simply represent a benign PSA bounce.

Quality of life after high-dose-rate brachytherapy monotherapy for prostate cancer.

PURPOSE: There is little information in the literature on health-related quality of life (HRQOL) changes due to high-dose-rate (HDR) brachytherapy monotherapy for prostate cancer. MATERIALS AND METHODS: We conducted a prospective study of HRQOL changes due to HDR brachytherapy monotherapy for low risk or favorable intermediate risk prostate cancer. Sixty-four of 84 (76 %) patients who were treated between February 2011 and April 2013 completed 50 questions comprising the Expanded Prostate Cancer Index Composite (EPIC) before treatment and 6 and/or 12 months after treatment. RESULTS: Six months after treatment, there was a significant decrease (p <0.05) in EPIC urinary, bowel, and sexual scores, including urinary overall, urinary function, urinary bother, urinary irritative, bowel overall, bowel bother, sexual overall, and sexual bother scores. By one year after treatment, EPIC urinary, bowel, and sexual scores had increased and only the bowel overall and bowel bother scores remained significantly below baseline values. CONCLUSIONS: HDR brachytherapy monotherapy is well-tolerated in patients with low and favorable intermediate risk prostate cancer. EPIC urinary and sexual domain scores returned to close to baseline 12 months after HDR brachytherapy.

Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes.

PURPOSE: To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. MATERIALS AND METHODS: One hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. RESULTS: Median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17%) patients developed Grade 2 acute urinary retention. American Urological Association (AUA) symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p=0.04). There was no ≥ Grade 3 acute toxicity. CONCLUSIONS: Dosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes.

Lipiodol as a fiducial marker for image-guided radiation therapy for bladder cancer.

PURPOSE: To evaluate Lipiodol as a liquid, radio-opaque fiducial marker for image-guided radiation therapy (IGRT) for bladder cancer. MATERIALS AND METHODS: Between 2011 and 2012, 5 clinical T2a-T3b N0 M0 stage II-III bladder cancer patients were treated with maximal transurethral resection of a bladder tumor (TURBT) and image-guided radiation therapy (IGRT) to 64.8 Gy in 36 fractions ± concurrent weekly cisplatin-based or gemcitabine chemotherapy. Ten to 15mL Lipiodol, using 0.5mL per injection, was injected into bladder submucosa circumferentially around the entire periphery of the tumor bed immediately following maximal TURBT. The authors looked at inter-observer variability regarding the size and location of the tumor bed (CTVboost) on computed tomography scans with versus without Lipiodol. RESULTS: Median follow-up was 18 months. Lipiodol was visible on every orthogonal two-dimensional kV portal image throughout the entire, 7-week course of IGRT. There was a trend towards improved inter-observer agreement on the CTVboost with Lipiodol (p = 0.06). In 2 of 5 patients, the tumor bed based upon Lipiodol extended outside a planning target volume that would have been treated with a radiation boost based upon a cystoscopy report and an enhanced computed tomography (CT) scan for staging. There was no toxicity attributable to Lipiodol. CONCLUSIONS: Lipiodol constitutes a safe and effective fiducial marker that an urologist can use to demarcate a tumor bed immediately following maximal TURBT. Lipiodol decreases inter-observer variability in the definition of the extent and location of a tumor bed on a treatment planning CT scan for a radiation boost.

External beam radiation therapy and a low-dose-rate brachytherapy boost without or with androgen deprivation therapy for prostate cancer.

PURPOSE: To assess outcomes with external beam radiation therapy (EBRT) and a low-dose-rate (LDR) brachytherapy boost without or with androgen deprivation therapy (ADT) for prostate cancer. MATERIALS AND METHODS: From January 2001 through August 2011, 120 intermediate-risk or high-risk prostate cancer patients were treated with EBRT to a total dose of 4,500 cGy in 25 daily fractions and a palladium-103 LDR brachytherapy boost of 10,000 cGy (n = 90) or an iodine-125 LDR brachytherapy boost of 11,000 cGy (n = 30). ADT, consisting of a gonadotropin-releasing hormone agonist ± an anti-androgen, was administered to 29/92 (32%) intermediate-risk patients for a median duration of 4 months and 26/28 (93%) high-risk patients for a median duration of 28 months. RESULTS: Median follow-up was 5.2 years (range, 1.1-12.8 years). There was no statistically-significant difference in biochemical disease-free survival (bDFS), distant metastasis-free survival (DMFS), or overall survival (OS) without or with ADT. Also, therewas no statistically-significant difference in bDFS, DMFS, or OS with a palladium-103 vs. an iodine-125 LDR brachytherapy boost. CONCLUSIONS: There was no statistically-significant difference in outcomes with the addition of ADT, though the power of the current study was limited. The Radiation Therapy Oncology Group 0815 and 0924 phase III trials, which have accrual targets of more than 1,500 men, will help to clarify the role ADT in locally-advanced prostate cancer patients treated with EBRT and a brachytherapy boost. Palladium-103 and iodine- 125 provide similar bDFS, DMFS, and OS.

Current concepts in penile cancer.

This review highlights the significant advances made in the diagnosis and management of penile cancer. This often-aggressive tumor phenotype has been characterized by its poor prognosis, mostly attributable to its late presentation and heterogeneity of surgical care because of the paucity of cases treated at most centers. Recent advances in understanding of the risk factors predisposing to penile cancer, including its association with the human papilloma virus (HPV), have brought forth the socioepidemiologic concept of HPV vaccination in certain high-risk populations and countries, which remains highly debated. The management of penile cancer has evolved in recent years with the adoption of penile-sparing and minimally invasive surgical approaches to the inguinal lymph nodes, which are a frequent site of regional spread for this malignancy. Lastly, this review highlights the importance of adopting a multimodal approach consisting of neoadjuvant systemic chemotherapy followed by consolidative surgical resection in patients presenting with bulky/locally advanced nodal metastases from penile cancer.

Penile cancer: Clinical Practice Guidelines in Oncology.

Squamous cell carcinoma of the penis represents approximately 0.5% of all cancers among men in the United States and other developed countries. Although rare, it is associated with significant disfigurement, and only half of the patients survive beyond 5 years. Proper evaluation of both the primary lesion and lymph nodes is critical, because nodal involvement is the most important factor of survival. The NCCN Clinical Practice Guidelines in Oncology for Penile Cancer provide recommendations on the diagnosis and management of this devastating disease based on evidence and expert consensus.

Bladder cancer.

Bladder cancer is the fourth most common cancer in the United States. Urothelial carcinoma that originates from the urinary bladder is the most common subtype. These NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) provide recommendations on the diagnosis and management of non-muscle-invasive and muscle-invasive urothelial carcinoma of the bladder. This version of the guidelines provides extensive reorganization and updates on the principles of chemotherapy management.

Primary bladder preservation treatment for urothelial bladder cancer.

BACKGROUND: Significant advancements have occurred in surgical procedures and chemoradiation therapy for bladder preservation. METHODS: This review addresses primary treatment options for bladder cancer, including an overview of bladder-sparing strategies. RESULTS: Surgical series demonstrate that highly selected patients with cT2N0M0 urothelial bladder cancers can be managed with partial cystectomy and bilateral pelvic lymphadenectomy. For patients with cT2N0M0 to cT4aN0M0 urothelial bladder cancers, neoadjuvant chemotherapy followed by radical cystectomy or maximal transurethral resection of the bladder tumor (TURBT) followed by chemoradiation therapy results in equivalent survival rates. However, each treatment option has a different impact on quality of life. Current chemoradiation therapy trials are evaluating novel approaches to improve outcomes. CONCLUSIONS: Maximal TURBT followed by chemoradiation therapy demonstrated equivalent survival with radical cystectomy while preserving bladder function in the majority of patients. Future efforts will be directed toward improving survival and quality of life.

Radiation therapy and esophageal cancer.

BACKGROUND: Squamous cell carcinoma and adenocarcinoma account for more than 90% of all esophageal cancer cases. Although the incidence of squamous cell carcinoma has declined, the incidence of adenocarcinoma has risen due to increases in obesity and gastroesophageal reflux disease. METHODS: The authors examine the role of radiation therapy alone (external beam and brachytherapy) for the management of esophageal cancer or combined with other modalities. The impact on staging and appropriate stratification of patients referred for curative vs palliative intent with modalities is reviewed. The authors also explore the role of emerging radiation technologies. RESULTS: Current data show that neoadjuvant chemoradiotherapy followed by surgical resection is the accepted standard of care, with 3-year overall survival rates ranging from 30% to 60%. The benefit of adjuvant radiation therapy is limited to patients with node-positive cancer. The survival benefit of surgical resection after chemoradiotherapy remains controversial. External beam radiation therapy alone results in few long-term survivors and is considered palliative at best. Radiation dose-escalation has failed to improve local control or survival. Brachytherapy can provide better long-term palliation of dysphagia than metal stent placement. Although three-dimensional conformal treatment planning is the accepted standard, the roles of IMRT and proton therapy are evolving and potentially reduce adverse events due to better sparing of normal tissue. CONCLUSIONS: Future directions will evaluate the benefit of induction chemotherapy followed by chemoradiotherapy, the role of surgery in locally advanced disease, and the identification of responders prior to treatment based on microarray analysis.

Providing a fast conversion of total dose to biological effective dose (BED) for hybrid seed brachytherapy.

Optimization of permanent seed implant brachytherapy plans for treatment of prostate cancer should be based on biological effective dose (BED) distributions, since dose does not accurately represent biological effects between different types of sources. Currently, biological optimization for these plans is not feasible due to the amount of time necessary to calculate the BED distribution. This study provides a fast calculation method, based on the total dose, to calculate the BED distribution. Distributions of various numbers of hybrid seeds were used to calculate total dose distributions, as well as BED distributions. Hybrid seeds are a mixture of different isotopes (in this study (125)I and (103)Pd). Three ratios of hybrid seeds were investigated: 25/75, 50/50, and 75/25. The total dose and BED value from each voxel were coupled together to produce graphs of total dose vs. BED. Equations were then derived from these graphs. The study investigated four types of tissue: bladder, rectum, prostate, and other normal tissue. Equations were derived from the total dose - BED correspondence. Accuracy of conversion from total dose to BED was within 2 Gy; however, accuracy of conversion was found to be better for high total dose regions as compared to lower dose regions. The method introduced in this paper allows one to perform fast conversion of total dose to BED for brachytherapy using hybrid seeds, which makes the BED-based plan optimization practical. The method defined here can be extended to other ratios, as well as other tissues that are affected by permanent seed implant brachytherapy (i.e., breast).

Skin dose in radiation treatment of the left breast: Analysis in the context of prone versus supine treatment technique.

PURPOSE: To determine how the skin dose varies in patients receiving radiation treatment for breast cancer in the prone and supine positions. METHODS: Fifty patients were scanned in the prone and supine positions. A radiation treatment plan was created for the left breast using a 6-MV beam for a prescribed dose of 42.66 Gy in 16 fractions. The dose was calculated using 1- and 2.5-mm calculation grid sizes and the surface dose was compared in both techniques. RESULTS: The median gantry angles relative to the skin surface at the central axis were 8 and 52 degrees for treatment in the prone and supine positions, respectively. The mean dose difference between the prone and supine techniques was statistically significant from 3- to 5-mm depth for both grid sizes. For the 1-mm calculation grid size, the doses at 3-, 4-, and 5-mm depths in the prone and supine techniques were 87.80% and 89.10% (P < 0.003), 91.92% and 94.50% (P < 0.00), and 95.30% and 98.20% (P < 0.00), respectively; for the 2.5-mm grid size, the respective doses were 87.10% and 88.59% (P < 0.00), 91.60% and 94.63% (P < 0.00), and 95.10% and 97.80% (P < 0.00), respectively. CONCLUSIONS: This study demonstrates that the prone technique facilitates a relatively lower skin dose than the supine technique. This observation is probably due to the beam angle. The beam is more perpendicular to the skin surface in the prone technique, whereas it is more tangential in the supine technique, which may deliver a higher skin dose. Thus, the dose to the skin should be evaluated in the prone technique, and if desired, the skin dose could be carefully augmented via a bolus or beam spoiler.

Accelerated partial breast irradiation: potential roles following breast-conserving surgery.

BACKGROUND: Multiple randomized trials comparing mastectomy to lumpectomy and whole breast irradiation (WBI) have shown equivalent survival outcomes in early-stage breast cancer. WBI requires a treatment course of several weeks, which has resulted in limited access to breast-conserving therapy in certain populations. A shorter accelerated course of partial breast irradiation (APBI) has been investigated recently. METHODS: This article reviews the current medical literature, including randomized trials and prospective institutional studies of APBI and the current recommendations regarding the use of this emerging technique. RESULTS: Several APBI techniques have been developed, including brachytherapy and external beam methods. The longest follow-up data are available for multicatheter interstitial brachytherapy, a technique that is not commonly used. Other methods, including balloon brachytherapy and external beam three-dimensional conformal techniques, have limited follow-up that shows similar local control rates to whole breast irradiation in highly selected patients. Guidelines for the appropriate use of APBI have been published. CONCLUSIONS: While APBI may increase access to breast conservation therapy for some women with early-stage breast cancer, follow-up data demonstrating the efficacy of this relatively new treatment approach are limited. Therefore, strict evidence-based selection criteria should be applied when evaluating patients who may be appropriate for APBI.

Emerging technologies in prostate cancer radiation therapy: improving the therapeutic window.

BACKGROUND: Radiation therapy is a standard of care in the treatment of prostate cancer. Relatively recent advances in technologies in the delivery of radiation therapy are altering our current approach to treatment of prostate cancer. METHODS: This review discusses the results of retrospective, prospective, and randomized clinical trials that have evaluated clinical outcomes in prostate cancer treated with newer radiation therapy technologies. RESULTS: Randomized trials have demonstrated that higher doses of radiation therapy improve clinical outcomes but with increased toxicity to normal tissue. The introduction of more conformal radiation therapy techniques such as intensity-modulated radiation therapy, proton therapy, stereotactic body radiotherapy, and brachytherapy have allowed for further dose escalation with simultaneous reduction in toxicity. However, use of more conformal treatments requires a better understanding of prostate motion and the ability to track prostate movements in real time. CONCLUSIONS: Technological advancements have improved radiation dose delivery to the prostate and have reduced normal tissue toxicity. Randomized trials are warranted to ultimately evaluate clinical benefit and outcomes.

Radiation therapy for rectal cancer: current status and future directions.

BACKGROUND: Treatment for rectal cancer has evolved over the past 70 years from surgery alone to the selective use of trimodality therapy for high-risk patients. Radiotherapy (RT) has improved the potential for tumor downstaging, thus enhancing sphincter preservation and local control. METHODS: This article reviews the evolution of strategies that incorporate pelvic RT, intraoperative RT, and high-dose-rate endorectal brachytherapy (HDRBT). By tracing the arc of the pendulum that has swung from postoperative RT to preoperative RT, we address the current standard of care and explore the potential of novel radiation techniques and radiosensitizing agents to improve outcomes. RESULTS: With randomized trial data confirming that preoperative RT in addition to chemotherapy improves local control and decreases acute and late morbidity, neoadjuvant programs have now demonstrated the prognostic significance of downstaging as well. Patients with tumors that have a good response to preoperative treatment have superior survival. CONCLUSIONS: Future studies will determine the optimal regimen to enhance the pathologic complete or near complete response rates for locally advanced disease. Advances in radiation technology are being investigated to determine whether efficacy can be increased and toxicity decreased so that more aggressive chemotherapeutic agents can be combined. With the growing improvements in combined modality therapy, a future of better rectal cancer outcomes looms brighter than ever before.

Biological Indices Evaluation of Various Treatment Techniques for Left-Sided Breast Treatment.

PURPOSE: To compare dose to organs at risk (OARs) and biological evaluation using normal tissue complication probability (NTCP) for left-sided breast radiation therapy in 4 techniques: supine free breathing (SFB), supine deep inspiration breath hold (SDIBH), prone free breathing (PFB), and prone deep inspiration breath hold (PDIBH). METHODS AND MATERIALS: Twenty-five patients with left-sided breast cancer suitable for this study underwent a computed tomography scan using SFB, SDIBH, PFB, and PDIBH. One radiation oncologist contoured the planning target volume and OAR (cardiac components). Dose-volume histograms and NTCPs for the heart, left ventricle (LV), left anterior descending artery (LAD), and left lung were calculated for all 4 techniques. RESULTS: The mean heart dose in PDIBH is 0.77 Gy, which is statistically significantly lower than in SFB (1.88 Gy, P < .0001), SDIBH (0.97 Gy, P < .001), and PFB (0.85 Gy, P < .001). The mean left lung dose is 0.69 Gy in PFB and 0.88 Gy in PDIBH. PFB and PDIBH have statistically significantly lower doses compared with SFB (6.09 Gy, P < .0001) and SDIBH (5.41 Gy, P < .0001). The mean NTCP in SFB for the heart, LV, and LAD is 0.27%, 0.62%, and 4.23%, respectively, and it is negligible for other techniques. CONCLUSIONS: We found that PDIBH had a dosimetrically lower mean dose for the heart and LV compared with the other 3 techniques. In addition, SDIBH, PFB and PDIBH had statistically significantly lower NTCP for the heart, LV, and LAD compared with SFB. NTCP for the left lung was statistically significantly lower for prone techniques compared with supine techniques. Therefore we concluded that, compared with SDIBH, PDIBH provides the added benefit of sparing the heart while keeping the benefit of sparing the lung as in the prone technique.