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.

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.

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.

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.

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.

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.

Implications of staged reconstruction and adjuvant brachytherapy in the treatment of recurrent soft tissue sarcoma.

PURPOSE: Prior studies illustrated a reduction in wound complications with the use of staged reconstruction (SR) and negative pressure wound therapy when treating soft tissue sarcoma (STS) with surgical resection followed by high-dose-rate adjuvant brachytherapy. The purpose of this study is to compare the outcomes of SR and immediate reconstruction (IR) brachytherapy in recurrent STS. METHODS AND MATERIALS: A retrospective review of 40 patients with recurrent STS of the local extremity and trunk treated with resection followed by adjuvant brachytherapy alone. Margin status was defined as positive (SM(+)) if there was microscopic involvement (R1) or ≤1 mm margin and negative (SM(-)) if >1 mm margin was obtained. SR and IR were compared regarding toxicity, local control, and limb preservation. RESULTS: Median followup was 27 months. When comparing the SR (n = 22) and IR (n = 18) cohorts, there was a significantly lower final SM(+) rate in SR (32% vs. 83%, p < 0.01). A 2-year local control benefit seen with SR (80% vs. 34%; p = 0.012) and a final SM(-) (81% vs. 39%; p = 0.023). SR was associated with less toxicity on multivariate analysis, including a 90% decrease in persistent edema, an 80% decrease in wound dehiscence, and a 94% decrease in nonhealing wounds, when compared to IR. Ten of 31 (32%) extremity cases required eventual amputation from either chronic wound complications (n = 4) or local recurrence (n = 6). SR predicted for a benefit in 2-year limb preservation (88% vs. 50%; p = 0.008). CONCLUSION: In our series, the treatment with SR brachytherapy resulted in less morbidity and an improved final SM(-) rate. This technique translated to an improvement in both local control and limb preservation of recurrent STS.

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.

Dosimetric Coverage of the Prostate, Normal Tissue Sparing, and Acute Toxicity with High-Dose-Rate Brachytherapy for Large Prostate Volumes

To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes.

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.

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. .

A dosimetric comparison of volumetric modulated arc therapy with step-and-shoot intensity modulated radiation therapy for prostate cancer.

PURPOSE: To compare variable dose-rate volumetric modulated arc therapy (VMAT) with 7-field, step-and-shoot intensity modulated radiation therapy (IMRT) in prostate cancer patients treated with a consistent planning target volume (PTV) to a uniform total radiation therapy dose. METHODS AND MATERIALS: We studied 32 patients who received 8100 cGy in 45 daily fractions to their prostate and proximal 1 cm of the seminal vesicles using variable dose rate VMAT (n = 22) or 7-field, step-and-shoot IMRT (n = 10) for intermediate-risk or high-risk prostate cancer between July 2010 and April 2013. In 90% of patients, VMAT was delivered with 2 arcs. To have an unbiased comparison of plan quality, patients who were treated with VMAT were also planned with IMRT and vice versa. Each patient served as his own control for the comparison. RESULTS: VMAT reduced median radiation beam-on time from 4.3 to 3.4 minutes (P = .03). There was no statistically significant difference in PTV volumes between the VMAT and step-and-shoot IMRT groups (P = .76). VMAT dose distributions were more homogeneous (P = .003). There was no difference between groups with regard to rectal V60, V65, V70, V75, bladder V65, V70, V75, V80, or femoral heads V33. CONCLUSIONS: Two-arc VMAT resulted in shorter beam-on times and more homogenous dose distributions than 7-field, step-and-shoot IMRT for prostate cancer. With decreased beam-on time, the intrafraction motion during irradiation is reduced, thus improving confidence that the delivered dose distribution agrees with the plan.

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.

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.

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, there was 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. .

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.

A dosimetric study of polyethylene glycol hydrogel in 200 prostate cancer patients treated with high-dose rate brachytherapy±intensity modulated radiation therapy.

BACKGROUND AND PURPOSE: We sought to analyze the effect of polyethylene glycol (PEG) hydrogel on rectal doses in prostate cancer patients undergoing radiotherapy. MATERIALS AND METHODS: Between July 2009 and April 2013, we treated 200 clinically localized prostate cancer patients with high-dose rate (HDR) brachytherapy±intensity modulated radiation therapy. Half of the patients received a transrectal ultrasound (TRUS)-guided transperineal injection of 10mL PEG hydrogel (DuraSeal™ Spinal Sealant System; Covidien, Mansfield, MA) in their anterior perirectal fat immediately prior to the first HDR brachytherapy treatment and 5mL PEG hydrogel prior to the second HDR brachytherapy treatment. Prostate, rectal, and bladder doses and prostate-rectal distances were calculated based upon treatment planning CT scans. RESULTS: There was a success rate of 100% (100/100) with PEG hydrogel implantation. PEG hydrogel significantly increased the prostate-rectal separation (mean±SD, 12±4mm with gel vs. 4±2mm without gel, p<0.001) and significantly decreased the mean rectal D2 mL (47±9% with gel vs. 60±8% without gel, p<0.001). Gel decreased rectal doses regardless of body mass index (BMI). CONCLUSIONS: PEG hydrogel temporarily displaced the rectum away from the prostate by an average of 12mm and led to a significant reduction in rectal radiation doses, regardless of BMI.

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.

Intravesical lipiodol injection technique for image-guided radiation therapy for bladder cancer.

INTRODUCTION: To describe the technique of injecting Lipiodol in the submucosa of the urinary bladder wall as a novel modality to improve localization of muscle-invasive bladder tumors before image-guided radiation therapy. TECHNICAL CONSIDERATIONS: Eight patients underwent submucosal Lipiodol injections at transurethral bladder tumor reresection. A rigid cystoscope with a working port was used to inject Lipiodol into bladder submucosa circumferentially around the tumor bed (2-3 mm from margin of resection). Approximately 20-30 injections were used to demarcate the tumor bed for external beam radiation therapy, which was used as part of a bladder-sparing approach. All patients were diagnosed with clinically localized, high-grade, muscle-invasive carcinoma and were deemed nonsurgical candidates or were unwilling to undergo radical cystectomy. Five of the 8 patients received radiation at our institution. Lipiodol injections (95%) were visible on treatment planning computed tomographic scans and kilovoltage portal images throughout the 7-week course of image-guided radiation therapy. In 2 of 5 patients, the tumor bed based on Lipiodol extended outside a planning target volume that would have been treated with radiation therapy based on cystoscopy reports and computed tomographic scans without Lipiodol. There were no adverse events or treatment-related toxicities secondary to Lipiodol injection. CONCLUSION: Intravesical Lipiodol injection is an easy-to-perform technique that is safe and effective. Lipiodol serves as a fiducial marker that improves tumor bed localization for radiation therapy, thereby reducing the likelihood of missing the tumor.

High-dose-rate brachytherapy with or without intensity modulated radiation therapy as salvage treatment for an isolated, gross local recurrence of prostate cancer post-prostatectomy.

PURPOSE: To evaluate the use of high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) as salvage therapy for patients with an isolated, gross local recurrence of prostate cancer after radical prostatectomy. METHODS AND MATERIALS: Between October 2009 and May 2013, the authors treated six patients with salvage iridium-192 HDR brachytherapy ± IMRT for biopsy-proven, recurrent prostate cancer post-prostatectomy. In each patient, a pelvic MRI scan or CT scan demonstrated a nodule (range 1.6, 4.7 cm) in the prostate bed. Although prostate-specific antigen values were 0.2-9.5 ng/mL at the time of salvage brachytherapy, there was no pelvic adenopathy on CT or MRI scan, and a bone scan was negative in all cases. Five patients were treated with IMRT to 4500-5040 cGy in 25-28 fractions to the prostate bed followed by two 950 cGy HDR brachytherapy fractions separated by 1-2 weeks. A sixth patient underwent HDR brachytherapy monotherapy consisting of 3800 cGy in four fractions over 3 days. Toxicities were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: Median followup was 9 months (range 3, 40 months). All six patients have been free of androgen deprivation therapy and have an undetectable prostate-specific antigen. One patient developed late Grade 2 urinary incontinence. There was no late grade ≥2 gastrointestinal toxicity. CONCLUSIONS: HDR brachytherapy ± IMRT is a safe and effective salvage therapy option for an isolated, gross local recurrence of prostate cancer after radical prostatectomy and merits further study.