The Impact of Adjuvant Therapy on Survival and Recurrence Patterns in Women With Early-Stage Uterine Carcinosarcoma: A Multi-institutional Study.

OBJECTIVE: The aim of the study was to characterize the impact of adjuvant therapy on survival in women with stage I/II uterine carcinosarcoma after primary surgery. METHODS: We reviewed records of 118 consecutively treated women with 2009 International Federation of Gynecology and Obstetrics stage I/II uterine carcinosarcoma who underwent hysterectomy between 1990 and 2014 at 4 academic institutions. Patients were categorized by adjuvant treatment group into observation, chemotherapy only, radiation only, and combined chemotherapy and radiation. Survival analyses were conducted using Kaplan-Meier and Cox proportional hazards models. RESULTS: Median follow-up was 28 months (range, 1-244 months). Lymphadenectomy was performed in 94 patients (80%). Postoperative management included observation (n = 37 [31%]), chemotherapy alone (n = 19 [16%]), radiation therapy (RT) alone (n = 24 [20%]), and combined RT and chemotherapy (n = 38 [32%]). Radiation therapy modality included vaginal brachytherapy in 22 patients, pelvic external beam RT in 21 patients, and combination in 19 patients. In 58% of women, chemotherapy consisted of carboplatin/paclitaxel. Median overall survival for all women was 97 months. On univariate analysis, adjuvant treatment group was associated with improved overall survival (hazard ratio [HR], 0.74; confidence interval [CI], 0.58-0.96; p = 0.02), freedom from vaginal recurrence (HR, 0.55; CI, 0.37-0.82]; p = 0.004), and freedom from any recurrence (HR, 0.70; CI, 0.54-0.92; p = 0.01). Pairwise comparisons demonstrated a significant benefit to chemoradiation over other adjuvant treatments. Adjuvant treatment group remained a significant covariate for all 3 end points on multivariate analysis as well. In addition, lymphadenectomy improved overall survival on multivariate analysis (HR, 0.24; CI, 0.09-0.61; p = 0.003). Of patients under observation only who had a recurrence, 8 (44%) of 18 had a recurrence in the vagina as the sole site of recurrence. By contrast, of women who received vaginal brachytherapy, significantly fewer had a recurrence in the vagina (1/42 [2.3%]; p < 0.003, log-rank test). CONCLUSIONS: In women with early-stage uterine carcinosarcoma, our data suggest superior survival end points with combined RT and chemotherapy. The frequency of vaginal recurrence suggests a role for incorporating vaginal brachytherapy in the adjuvant management of this disease.

Tumor control probability reduction in gated radiotherapy of non-small cell lung cancers: a feasibility study.

We studied the feasibility of evaluating tumor control probability (TCP) reductions for tumor motion beyond planned gated radiotherapy margins. Tumor motion was determined from cone-beam CT projections acquired for patient setup, intrafraction respiratory traces, and 4D CTs for five non-small cell lung cancer (NSCLC) patients treated with gated radiotherapy. Tumors were subdivided into 1 mm sections whose positions and doses were determined for each beam-on time point. (The dose calculation model was verified with motion phantom measurements.) The calculated dose distributions were used to generate the treatment TCPs for each patient. The plan TCPs were calculated from the treatment planning dose distributions. The treatment TCPs were compared to the plan TCPs for various models and parameters. Calculated doses matched phantom measurements within 0.3% for up to 3 cm of motion. TCP reductions for excess motion greater than 5mm ranged from 1.7% to 11.9%, depending on model parameters, and were as high as 48.6% for model parameters that simulated an individual patient. Repeating the worst case motion for all fractions increased TCP reductions by a factor of 2 to 3, while hypofractionation decreased these reductions by as much as a factor of 3. Treatment motion exceeding gating margins by more than 5 mm can lead to considerable TCP reductions. Appropriate margins for excess motion are recommended, unless applying daily tumor motion verification and adjusting thegating window.

Characterization and identification of spatial artifacts during 4D-CT imaging.

PURPOSE: The purpose of this work is twofold: First, to characterize the artifacts occurring in helical 4D-CT imaging; second, to propose a method that can automatically identify the artifacts in 4D-CT images. The authors have designed a process that can automatically identify the artifacts in 4D-CT images, which may be invaluable in quantifying the quality of 4D-CT images and reducing the artifacts from the reconstructed images on a large dataset. METHODS: Given two adjacent stacks obtained from the same respiration phase, the authors determine if there are artifacts between them. The proposed method uses a "bridge" stack strategy to connect the two stacks. Using normalized cross correlation convolution (NCCC), the two stacks are mapped to the bridge stack and the best matching positions can be located. Using this position information, the authors can then determine if there are artifacts between the two stacks. By combining the matching positions with NCCC values, the performance can be improved. RESULTS: To validate the method, three expert observers independently labeled over 600 stacks on five patients. The results confirmed that high performance was obtained using the proposed method. The average sensitivity was about 0.87 and the average specificity was 0.82. The proposed method also outperformed the method of using respiratory signal (sensitivity increased from 0.50 to 0.87 and specificity increased from 0.70 to 0.82). CONCLUSIONS: This study shows that the spatial artifacts during 4D-CT imaging are characterized and can be located automatically by the proposed method. The method is relatively simple but effective. It provides a way to evaluate the artifacts more objectively and accurately. The reported approach has promising potential for automatically identifying the types and frequency of artifacts on large scale 4D-CT image dataset.

Image quality improvement in megavoltage cone beam CT using an imaging beam line and a sintered pixelated array system.

PURPOSE: To quantify the improvement in megavoltage cone beam computed tomography (MVCBCT) image quality enabled by the combination of a 4.2 MV imaging beam line (IBL) with a carbon electron target and a detector system equipped with a novel sintered pixelated array (SPA) of translucent Gd(2)O(2)S ceramic scintillator. Clinical MVCBCT images are traditionally acquired with the same 6 MV treatment beam line (TBL) that is used for cancer treatment, a standard amorphous Si (a-Si) flat panel imager, and the Kodak Lanex Fast-B (LFB) scintillator. The IBL produces a greater fluence of keV-range photons than the TBL, to which the detector response is more optimal, and the SPA is a more efficient scintillator than the LFB. METHODS: A prototype IBL + SPA system was installed on a Siemens Oncor linear accelerator equipped with the MVision(TM) image guided radiation therapy (IGRT) system. A SPA strip consisting of four neighboring tiles and measuring 40 cm by 10.96 cm in the crossplane and inplane directions, respectively, was installed in the flat panel imager. Head- and pelvis-sized phantom images were acquired at doses ranging from 3 to 60 cGy with three MVCBCT configurations: TBL + LFB, IBL + LFB, and IBL + SPA. Phantom image quality at each dose was quantified using the contrast-to-noise ratio (CNR) and modulation transfer function (MTF) metrics. Head and neck, thoracic, and pelvic (prostate) cancer patients were imaged with the three imaging system configurations at multiple doses ranging from 3 to 15 cGy. The systems were assessed qualitatively from the patient image data. RESULTS: For head and neck and pelvis-sized phantom images, imaging doses of 3 cGy or greater, and relative electron densities of 1.09 and 1.48, the CNR average improvement factors for imaging system change of TBL + LFB to IBL + LFB, IBL + LFB to IBL + SPA, and TBL + LFB to IBL + SPA were 1.63 (p < 10(- 8)), 1.64 (p < 10(- 13)), 2.66 (p < 10(- 9)), respectively. For all imaging doses, soft tissue contrast was more easily differentiated on IBL + SPA head and neck and pelvic images than TBL + LFB and IBL + LFB. IBL + SPA thoracic images were comparable to IBL + LFB images, but less noisy than TBL + LFB images at all imaging doses considered. The mean MTFs over all imaging doses were comparable, at within 3%, for all imaging system configurations for both the head- and pelvis-sized phantoms. CONCLUSIONS: Since CNR scales with the square root of imaging dose, changing from TBL + LFB to IBL + LFB and IBL + LFB to IBL + SPA reduces the imaging dose required to obtain a given CNR by factors of 0.38 and 0.37, respectively. MTFs were comparable between imaging system configurations. IBL + SPA patient image quality was always better than that of the TBL + LFB system and as good as or better than that of the IBL + LFB system, for a given dose.

Intratumoral talimogene laherparepvec injection with concurrent preoperative radiation in patients with locally advanced soft-tissue sarcoma of the trunk and extremities: phase IB/II trial.

BACKGROUND: Soft-tissue sarcomas (STS) in the extremities and trunk treated with standard-of-care preoperative external beam radiation therapy (EBRT) followed by surgical resection are associated with local and distant relapses. In preclinical studies, oncolytic virotherapy in sarcoma has demonstrated antitumor effects via direct intratumoral oncolysis and cytotoxic T-cell-mediated immune responses. Talimogene laherparepvec (TVEC) is a replication-competent, immune-enhanced, oncolytic herpes simplex virus type 1 engineered for intratumoral injection; it has been approved by the FDA for the treatment of locally advanced and metastatic melanoma. METHODS: We explored a novel combination of TVEC with standard-of-care EBRT administered preoperatively in patients with locally advanced STS of the extremities and trunk in a phase IB/II clinical trial. Thirty patients with primary STS >5 cm for which EBRT was indicated to achieve negative margins were enrolled. FDA-approved TVEC doses were used. Immune correlative studies in peripheral blood, biopsy and resected tumor tissues were performed. RESULTS: No dose-limiting toxicity was observed. Adverse events were similar to those reported in prior studies with TVEC. One patient with myxoid liposarcoma exhibited a partial response. Seven of the 29 (24%) evaluable patients achieved 95% pathological necrosis. None of the patients developed a herpes infection due to the treatment. Eight of the 29 (27%) patients developed postoperative wound complications, which is consistent with previous studies. None of the patients developed local recurrence after surgical resection of the primary sarcoma. 2-year progression-free and overall survival were 57% and 88%, respectively. Caspase-3 demonstrated increased expression of both in TVEC-treated tissue samples as compared with control samples treated with radiation alone. CONCLUSION: Preoperative intratumoral TVEC with concurrent EBRT for locally advanced STS is safe and well-tolerated. This combination treatment may enhance immune responses in some cases but did not increase the proposed rate of pathological necrosis. The Caspase-3 biomarker may be associated with a positive effect of TVEC in sarcoma tumor tissue and should be explored in future studies. TRIAL REGISTRATION NUMBER: NCT02453191.

Timing of surgery following neoadjuvant chemoradiation in rectal cancer: a retrospective analysis from an academic medical center.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) has been shown to achieve decreased local recurrence (LR) with lower toxicity in rectal cancer patients, but data confirming the optimal timing of surgery following this therapy is less robust. METHODS: The University of Iowa Cancer Registry was queried to identify all patients with stages II-III rectal cancer who received nCRT and surgery from 2000 through 2012. Primary endpoints were time interval to surgery (TI), and overall survival (OS). Secondary endpoints included pathologic outcomes, perioperative morbidities and postoperative complications. Patient characteristics and treatment regimens were compared. Univariate Cox proportional hazard models were used to study the association between TI and OS. Associations of TI with secondary endpoints were tested using Chi-square tests of association. RESULTS: Eighty-seven patients presented with stages II-III rectal cancer. Mean TI was 9.92 weeks. There was no significant association between TI and OS when comparing <8 to ≥8 weeks (P=0.23) or when considering the interval as a continuous variable (P=0.85). Increased LOS [median 7.00 days, P=0.05, HR 1.03 (1.00-1.06)] did correlate with worse survival outcomes. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection (P=0.05). CONCLUSIONS: OS was not influenced by longer intervals between nCRT and surgery. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection.

SBRT to adrenal metastases provides high local control with minimal toxicity.

PURPOSE: The adrenal glands are a common site of metastases because of their rich blood supply. Previously, adrenal metastases were treated with systemic chemotherapy or, more rarely, with surgical resection or palliative radiation therapy. Stereotactic body radiation therapy (SBRT) has recently emerged as an attractive noninvasive approach to definitively treat these lesions. We present our experience in treating adrenal metastases using SBRT and review the current literature. METHODS AND MATERIALS: This is a single-institution retrospective review of patients who received SBRT to adrenal metastases originating from various primary malignancies. Patients who were eligible for SBRT included those with limited metastatic disease (≤5 sites) with otherwise controlled metastatic disease and uncontrolled adrenal metastases. RESULTS: Ten patients met the study's inclusion criteria and received SBRT doses of 30 to 48 Gy in 3 to 5 fractions. Acute sequelae of SBRT treatment included 4 patients with grades 1 or 2 nausea, 3 patients with grade 1 fatigue, and 1 with grade 1 diarrhea. The median follow-up was 6 months with a median overall survival of 9.9 months. One patient demonstrated progressive adrenal gland disease 18.8 months after SBRT treatment. Seven patients developed new distant metastases after treatment, with a median progression-free survival of 3.4 months. Three months after SBRT to the adrenal gland, 1 patient developed a gastrointestinal bleed. CONCLUSIONS: These results complement the limited existing body of literature by demonstrating that SBRT provides good control of treated adrenal gland metastasis; however, high-grade late toxicities may occur. More stringent dose constraint limits may prevent associated serious adverse events.

Consuming a Ketogenic Diet while Receiving Radiation and Chemotherapy for Locally Advanced Lung Cancer and Pancreatic Cancer: The University of Iowa Experience of Two Phase 1 Clinical Trials.

Ketogenic diets are low in carbohydrates and high in fat, which forces cells to rely more heavily upon mitochondrial oxidation of fatty acids for energy. Relative to normal cells, cancer cells are believed to exist under a condition of chronic mitochondrial oxidative stress that is compensated for by increases in glucose metabolism to generate reducing equivalents. In this study we tested the hypothesis that a ketogenic diet concurrent with radiation and chemotherapy would be clinically tolerable in locally advanced non-small cell lung cancer (NSCLC) and pancreatic cancer and could potentially exploit cancer cell oxidative metabolism to improve therapeutic outcomes. Mice bearing MIA PaCa-2 pancreatic cancer xenografts were fed either a ketogenic diet or standard rodent chow, treated with conventionally fractionated radiation (2 Gy/fraction), and tumor growth rates were assessed daily. Tumors were assessed for immunoreactive 4-hydroxy-2-nonenal-(4HNE)-modfied proteins as a marker of oxidative stress. Based on this and another previously published preclinical study, phase 1 clinical trials in locally advanced NSCLC and pancreatic cancer were initiated, combining standard radiation and chemotherapy with a ketogenic diet for six weeks (NSCLC) or five weeks (pancreatic cancer). The xenograft experiments demonstrated prolonged survival and increased 4HNE-modfied proteins in animals consuming a ketogenic diet combined with radiation compared to radiation alone. In the phase 1 clinical trial, over a period of three years, seven NSCLC patients enrolled in the study. Of these, four were unable to comply with the diet and withdrew, two completed the study and one was withdrawn due to a dose-limiting toxicity. Over the same time period, two pancreatic cancer patients enrolled in the trial. Of these, one completed the study and the other was withdrawn due to a dose-limiting toxicity. The preclinical experiments demonstrate that a ketogenic diet increases radiation sensitivity in a pancreatic cancer xenograft model. However, patients with locally advanced NSCLC and pancreatic cancer receiving concurrent radiotherapy and chemotherapy had suboptimal compliance to the oral ketogenic diet and thus, poor tolerance.

O2⋠- and H2O2-Mediated Disruption of Fe Metabolism Causes the Differential Susceptibility of NSCLC and GBM Cancer Cells to Pharmacological Ascorbate.

Pharmacological ascorbate has been proposed as a potential anti-cancer agent when combined with radiation and chemotherapy. The anti-cancer effects of ascorbate are hypothesized to involve the autoxidation of ascorbate leading to increased steady-state levels of H2O2; however, the mechanism(s) for cancer cell-selective toxicity remain unknown. The current study shows that alterations in cancer cell mitochondrial oxidative metabolism resulting in increased levels of O2⋅- and H2O2 are capable of disrupting intracellular iron metabolism, thereby selectively sensitizing non-small-cell lung cancer (NSCLC) and glioblastoma (GBM) cells to ascorbate through pro-oxidant chemistry involving redox-active labile iron and H2O2. In addition, preclinical studies and clinical trials demonstrate the feasibility, selective toxicity, tolerability, and potential efficacy of pharmacological ascorbate in GBM and NSCLC therapy.

Favorable clinical outcomes of three-dimensional computer-optimized high-dose-rate prostate brachytherapy in the management of localized prostate cancer.

PURPOSE: To report PSA relapse-free survival and toxicity outcomes of prostate cancer patients who have undergone three-dimensional computer-optimized high-dose-rate (HDR) brachytherapy with external beam radiotherapy as definitive treatment. METHODS AND MATERIALS: One hundred five patients consecutively treated between 1998 and 2004 are reported. All patients were treated with HDR boost with lr 192 (5.5-7.0 Gy), based upon postimplant CT three-dimensional treatment planning using an in-house treatment plan optimization algorithm. Three-dimensional conformal external beam radiotherapy (45-50.4 Gy) was also administered 3 weeks after the HDR procedure. Toxicity was measured using National Cancer Institutes Common Toxicity Criteria and International Prostate Symptom Score indices. RESULTS: With a median followup of 44 months (8-79 months), the 5-year PSA relapse-free survival outcomes for low, intermediate and high-risk patients were 100%, 98%, and 92%, respectively, Median urinary toxicity, and 93% of patients denied rectal problems at the time of last followup. Erectile dysfunction was noted in 47% patients at the time of last followup, but overall 80% were able to achieve vaginal penetration when those who responded to sildenafil were included. CONCLUSION: Computer-optimized three-dimensional HDR prostate brachytherapy provides excellent disease control for even high risk localized prostate cancer. Significant toxicity has been minimal.

Impact on survival with adjuvant radiotherapy for clear cell, mucinous, and endometriod ovarian cancer: the SEER experience from 2004 to 2011.

OBJECTIVE: Evaluate the impact of radiotherapy on cause specific survival (CSS) and overall survival (OS) for stage (I-III) clear cell, mucinous, and endometriod ovarian cancer. METHODS: We analyzed incidence, survival, and treatments from the Surveillance, Epidemiology, and End Results (SEER) Program from 2004 to 2011 for clear cell, mucinous, and endometriod histologies of the ovary for stages (I-III). We examined CSS and OS for all three histologies combined and each histology with relation to the use of adjuvant radiation therapy (RT). Survival analysis was calculated by Kaplan-Meier and log-rank analysis. RESULTS: CSS was higher in individuals not receiving RT at 5 years (81% vs. 74%) and 10 years (74% vs. 65%, p=0.003). OS was higher in individuals not receiving RT at 5 years (76% vs. 73%) and 10 years (64% vs. 59%, p=0.039). Stage III patients receiving RT had a higher OS at 5 years (54% vs. 44%) and 10 year intervals (36% vs. 30%, p=0.037). Stage III patients with mucinous histology receiving RT had a higher OS at 5 years (50% vs. 36%) and 10 years (45% vs. 26%, p=0.052). CONCLUSION: Those receiving RT had a lower CSS and OS at 5 and 10 years. However, subgroup analysis revealed a benefit of RT in terms of OS for all stage III patients and for stage III patients with mucinous histology.

Using [(18)F]Fluorothymidine Imaged With Positron Emission Tomography to Quantify and Reduce Hematologic Toxicity Due to Chemoradiation Therapy for Pelvic Cancer Patients.

PURPOSE: The purpose of the present prospective clinical trial was to determine the efficacy of [(18)F]fluorothymidine (FLT)-identified active bone marrow sparing for pelvic cancer patients by correlating the FLT uptake change during and after chemoradiation therapy with hematologic toxicity. METHODS AND MATERIALS: Simulation FLT positron emission tomography (PET) images were used to spare pelvic bone marrow using intensity modulated radiation therapy (IMRT BMS) for 32 patients with pelvic cancer. FLT PET scans taken during chemoradiation therapy after 1 and 2 weeks and 30 days and 1 year after completion of chemoradiation therapy were used to evaluate the acute and chronic dose response of pelvic bone marrow. Complete blood counts were recorded at each imaging point to correlate the FLT uptake change with systemic hematologic toxicity. RESULTS: IMRT BMS plans significantly reduced the dose to the pelvic regions identified with FLT uptake compared with control IMRT plans (P<.001, paired t test). Radiation doses of 4 Gy caused an ∼50% decrease in FLT uptake in the pelvic bone marrow after either 1 or 2 weeks of chemoradiation therapy. Additionally, subjects with more FLT-identified bone marrow exposed to ≥4 Gy after 1 week developed grade 2 leukopenia sooner than subjects with less marrow exposed to ≥4 Gy (P<.05, Cox regression analysis). Apparent bone marrow recovery at 30 days after therapy was not maintained 1 year after chemotherapy. The FLT uptake in the pelvic bone marrow regions that received >35 Gy was 18.8% ± 1.8% greater at 30 days after therapy than at 1 year after therapy. The white blood cell, platelet, lymphocyte, and neutrophil counts at 1 year after therapy were all lower than the pretherapy levels (P<.05, paired t test). CONCLUSIONS: IMRT BMS plans reduced the dose to FLT-identified pelvic bone marrow for pelvic cancer patients. However, reducing hematologic toxicity is challenging owing to the acute radiation sensitivity (∼4 Gy) and chronic suppression of activity in bone marrow receiving radiation doses >35 Gy, as measured by the FLT uptake change correlated with the complete blood cell counts.

Once Daily High-dose Radiation (≥60 Gy) Treatment in Limited Stage Small Cell Lung Cancer.

BACKGROUND: To investigate outcomes and prognostic factors in patients treated with once daily high-dose (≥60 Gy) radiation therapy (HDRT) and concurrent platinum-based chemotherapy in limited stage small cell lung cancer (LS-SCLC). While we await current phase III trials to determine optimal radiation dose fractionation schemes in LS-SCLC, we report our experience in LS-SCLC with once daily HDRT. We hypothesized that HDRT would achieve similar efficacy and tolerability as twice daily therapy. METHODS: We conducted a single institution retrospective review of all patients with LS-SCLC who underwent curative intent treatment from 2005-2013. Patients treated with HDRT (≥60 Gy) and concurrent chemotherapy (cisplatin or carboplatin and etoposide) were included in our analysis. Clinicopathologic variables assessed include gender, performance status, time to treatment, response to treatment, toxicity, volumetric tumor response at 3 months, and use of prophylactic cranial irradiation (PCI). RESULTS: 42 patients with LS-SCLC who initiated concurrent chemoradiation from 2005 to 2013 were included in the analysis. 38 patients (90%) completed definitive treatment to the lung; 16 (38%) also completed PCI. Median failure free survival (FFS) and overall survival (OS) were 11.9 and 23.1 months, respectively. Two-year and 5-year OS rates were 47% (CI=30-62%) and 21% (CI=7-38%), respectively. On univariate analysis, PCI was associated with improved FFS but this was not significant (p=0.18). Gender was the only co-variate significantly associated with statistical differences in FFS (p=0.03) and OS (p=0.02). Grade 3 and 4 esophagitis were 10.5% and 2.6%, respectively. Pre-HDRT tumor volume and 3-month post-treatment tumor volume were both associated with FFS (p<0.01) but not OS. CONCLUSIONS: In this single institution series, daily HDRT demonstrated a 2-year OS of 47% in LS-SCLC. This compares well to the historical survival of daily fractionation (47%) from INT 0096 reported by Turrisi et. al. Male gender was predictive of significantly worse FFS and OS. Once daily HDRT has similar OS to twice-daily radiation schemes; however, further studies assessing once daily HDRT for LS-SCLC are warranted.

(32)P radioisotope therapy for recurrent pilocytic astrocytoma.

(32)P is a pure beta-emitter that has a depth of penetration of 2-3 mm and can be useful in the treatment of cystic lesions. Its effectiveness in the treatment of a selected brain tumor is illustrated here.

Bone marrow sparing in intensity modulated proton therapy for cervical cancer: Efficacy and robustness under range and setup uncertainties.

BACKGROUND AND PURPOSE: This study evaluates the potential efficacy and robustness of functional bone marrow sparing (BMS) using intensity-modulated proton therapy (IMPT) for cervical cancer, with the goal of reducing hematologic toxicity. MATERIAL AND METHODS: IMPT plans with prescription dose of 45 Gy were generated for ten patients who have received BMS intensity-modulated X-ray therapy (IMRT). Functional bone marrow was identified by (18)F-flourothymidine positron emission tomography. IMPT plans were designed to minimize the volume of functional bone marrow receiving 5-40 Gy while maintaining similar target coverage and healthy organ sparing as IMRT. IMPT robustness was analyzed with ±3% range uncertainty errors and/or ±3 mm translational setup errors in all three principal dimensions. RESULTS: In the static scenario, the median dose volume reductions for functional bone marrow by IMPT were: 32% for V(5Gy), 47% for V(10Gy), 54% for V(20Gy), and 57% for V(40Gy), all with p<0.01 compared to IMRT. With assumed errors, even the worst-case reductions by IMPT were: 23% for V(5Gy), 37% for V(10Gy), 41% for V(20Gy), and 39% for V(40Gy), all with p<0.01. CONCLUSIONS: The potential sparing of functional bone marrow by IMPT for cervical cancer is significant and robust under realistic systematic range uncertainties and clinically relevant setup errors.

Paddle-based rotating-shield brachytherapy.

PURPOSE: The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy. METHODS: Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose-volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm(3) (D(2cm(3)) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy3, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/ß = 3 Gy). RESULTS: P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D90 increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy10, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D90, compared to D-RSBT, were 16.6, 12.9, 7.2, 3.7, and 1.7 Gy10, respectively. P-RSBT HR-CTV D90-values were insensitive to the paddle size for paddles angled at less than 60°. Increasing the paddle angle from 5° to 60° resulted in only a 0.6 Gy10 decrease in HR-CTV D90 on average for five cases when the delivery times were set to 15 min/fx. The HR-CTV D90 decreased to 2.5 and 11.9 Gy10 with paddle angles of 90° and 120°, respectively. CONCLUSIONS: P-RSBT produces treatment plans that are dosimetrically and temporally superior to those of S-RSBT and D-RSBT, although P-RSBT systems may be more mechanically challenging to develop than S-RSBT or D-RSBT. A P-RSBT implementation with 4-6 shield paddles would be sufficient to outperform S-RSBT and D-RSBT if delivery times are constrained to less than 15 min/fx.

Curative radiotherapy for primary orbital lymphoma.

PURPOSE: To review our institutional experience with primary orbital lymphoma and determine the prognostic factors for survival, local control, and distant metastases. In addition, we also analyzed the risk factors for complications in the radiotherapeutic management of this tumor. METHODS AND MATERIALS: Between 1973 and 1998, 47 patients (29 women [62%] and 18 men [38%], median age 69 years, range 32-89) with Stage IAE orbital lymphoma were treated with curative intent at one department. Five had bilateral orbital involvement. The tumor was located in the eyelid and extraocular muscles in 23 (44%), conjunctiva in 17 (33%), and lacrimal apparatus in 12 (23%). The histologic features according to the World Heath Organization classification of lymphoid neoplasms was follicular lymphoma in 25, extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type in 8, diffuse large B-cell lymphoma in 12, mantle cell lymphoma in 6, and peripheral T-cell lymphoma in 1. For the purposes of comparison with the existing literature on orbital lymphomas, the grading system according to the Working Formulation was also recorded. The histologic grade was low in 33 (63%), intermediate in 18 (35%), and high in 1 (2%). All patients were treated with primary radiotherapy alone. The median dose for low-grade tumors was 3000 cGy (range 2000-4020); the median dose for intermediate and high-grade tumors was 4000 cGy (range 3000-5100). A lens-sparing approach was used in 19 patients (37%). Late complications for the lens and cornea were scored according to the subjective, objective, management, and analytic (SOMA) scale of the Late Effects of Normal Tissue (LENT) scoring system. The median follow-up was 55 months (range 6-232). RESULTS: The local control rate was 100% in the 52 orbits treated. The 5-year overall survival and relapse-free survival rate was 73.6% and 65.5%, respectively. Tumor grade and location did not predict for overall survival or relapse-free survival. Seven patients (15%) developed distant recurrence (brain 2, extremity 2, mediastinum 1, liver 1, and retroperitoneum 1). One patient (2%) developed cervical node metastasis. The 5- and 10-year cataract-free survival rate was 56.7% and 32.9%, respectively. Of the 12 lens complications, 8 were LENT Grade 1 and 4 were Grade 3 toxicity. Only male gender predicted for an increased risk of cataract formation. Radiotherapy dose and technique did not predict for cataract formation; however, none of the patients who underwent the lens-sparing technique developed Grade 3 lens toxicity or required surgical correction. Of the nine corneal events, two were Grade 1, four Grade 2, and three were Grade 3 toxicity. Ten dry eyes were recorded; all were mild, and no patient had severe dry eye syndrome. Neovascular glaucoma was seen in 1 patient. No injury to the retina or optic nerve was reported. CONCLUSION: Radiotherapy alone is a highly effective modality in the curative management of primary orbital lymphoma. Most complications were minimal and did not require medical or surgical intervention. Although the use of the lens-sparing technique did not influence the incidence of cataractogenesis, we continue to recommend this approach whenever possible, because our experience indicates a higher grade of toxicity occurs and a higher incidence of corrective surgery is needed in patients treated without lens protection.

Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism.

Cancer cells, relative to normal cells, demonstrate significant alterations in metabolism that are proposed to result in increased steady-state levels of mitochondrial-derived reactive oxygen species (ROS) such as O2(•-)and H2O2. It has also been proposed that cancer cells increase glucose and hydroperoxide metabolism to compensate for increased levels of ROS. Given this theoretical construct, it is reasonable to propose that forcing cancer cells to use mitochondrial oxidative metabolism by feeding ketogenic diets that are high in fats and low in glucose and other carbohydrates, would selectively cause metabolic oxidative stress in cancer versus normal cells. Increased metabolic oxidative stress in cancer cells would in turn be predicted to selectively sensitize cancer cells to conventional radiation and chemotherapies. This review summarizes the evidence supporting the hypothesis that ketogenic diets may be safely used as an adjuvant therapy to conventional radiation and chemotherapies and discusses the proposed mechanisms by which ketogenic diets may enhance cancer cell therapeutic responses.

Comparison and consensus guidelines for delineation of clinical target volume for CT- and MR-based brachytherapy in locally advanced cervical cancer.

OBJECTIVE: To create and compare consensus clinical target volume (CTV) contours for computed tomography (CT) and 3-Tesla (3-T) magnetic resonance (MR) image-based cervical-cancer brachytherapy. METHODS AND MATERIALS: Twenty-three experts in gynecologic radiation oncology contoured the same 3 cervical cancer brachytherapy cases: 1 stage IIB near-complete response (CR) case with a tandem and ovoid, 1 stage IIB partial response (PR) case with tandem and ovoid with needles, and 1 stage IB2 CR case with a tandem and ring applicator. The CT contours were completed before the MRI contours. These were analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with κ statistics as a measure of agreement between participants. The conformity index was calculated for each of the 6 data sets. Dice coefficients were generated to compare the CT and MR contours of the same case. RESULTS: For all 3 cases, the mean tumor volume was smaller on MR than on CT (P<.001). The κ and conformity index estimates were slightly higher for CT, indicating a higher level of agreement on CT. The Dice coefficients were 89% for the stage IB2 case with a CR, 74% for the stage IIB case with a PR, and 57% for the stage IIB case with a CR. CONCLUSION: In a comparison of MR-contoured with CT-contoured CTV volumes, the higher level of agreement on CT may be due to the more distinct contrast medium visible on the images at the time of brachytherapy. MR at the time of brachytherapy may be of greatest benefit in patients with large tumors with parametrial extension that have a partial or complete response to external beam. On the basis of these results, a 95% consensus volume was generated for CT and for MR. Online contouring atlases are available for instruction at http://www.nrgoncology.org/Resources/ContouringAtlases/GYNCervicalBrachytherapy.aspx.

Randomized trial of pentoxifylline and vitamin E vs standard follow-up after breast irradiation to prevent breast fibrosis, evaluated by tissue compliance meter.

PURPOSE: To conduct a randomized clinical trial to determine whether the combination of pentoxifylline (PTX) and vitamin E given for 6 months after breast/chest wall irradiation effectively prevents radiation-induced fibrosis (RIF). METHODS AND MATERIALS: Fifty-three breast cancer patients with localized disease were enrolled and randomized to treatment with oral PTX 400 mg 3 times daily and oral vitamin E 400 IU daily for 6 months after radiation (n=26), or standard follow up (n=27). Tissue compliance meter (TCM) measurements were obtained at 18 months to compare tissue compliance in the irradiated and untreated breast/chest wall in treated subjects and controls. Measurements were obtained at 2 mirror image sites on each breast/chest wall, and the average difference in tissue compliance was scored. Differences in TCM measurements were compared using a t test. Subjects were followed a minimum of 2 years for local recurrence, disease-free survival, and overall survival. RESULTS: The mean difference in TCM measurements in the 2 groups was 0.88 mm, median of 1.00 mm (treated) and 2.10 mm, median of 2.4 mm (untreated). The difference between the 2 groups was significant (P=.0478). Overall survival (100% treated, 90.6% controls at 5 years) and disease-free survival (96.2% treated, 86.8% controls at 5 years) were not significantly different in the 2 groups. CONCLUSIONS: This study of postirradiation breast cancer patients treated with PTX/vitamin E or standard follow-up indicated a significant difference in radiation-induced fibrosis as measured by TCM. There was no observed impact on local control or survival within the first 2 years of follow-up. The treatment was safe and well tolerated. Pentoxifylline/vitamin E may be clinically useful in preventing fibrosis after radiation in high-risk patients.