Definitive external-beam radiotherapy versus radical prostatectomy in clinically localized high-risk prostate cancer: a retrospective study.

BACKGROUND: Optimal treatment of high-risk prostate cancer remains controversial. We aimed to compare treatment outcomes of prostate cancer patients treated with definitive external-beam radiotherapy (ExRT) or radical prostatectomy (RP). METHODS: The records of 120 high-risk clinical stage T2b-T4 N0 M0 prostate cancer patients treated with definitive ExRT or RP were reviewed. Patients with pretreatment prostate-specific antigen (PSA) levels ≥20 ng/mL or clinical ≥T3 stage or Gleason score (GS) ≥8 were included in the study. Biochemical failure free survival (BFFS), distant metastasis free survival (DMFS), cancer-specific survival (CSS) and overall survival (OS) were analyzed. Cox regression analysis was performed to determine predictors of BF. RESULTS: Seventy-two patients received definitive ExRT with androgen-deprivation therapy in 95.8% and 48 patients underwent RP with pelvic lymph node dissection. Mean age (67.7 ± 6.6 vs 64.5 ± 7.6 year, p = 0.017) and the rate of patients with PSA levels ≥20 ng/mL (69.4% vs 47.9%, p = 0.022) were higher in the definitive ExRT group than the RP group. Distributions of GS and clinical T stage were similar. Mean follow-up was 60.2 ± 30.3 months in the definitive ExRT group and 41.3 ± 21.5 months in the RP group (p <  0.001). Twenty-five % of the RP group received adjuvant ExRT and 41.7% received salvage ExRT. Biochemical failure was significantly higher (52.1% vs 21.4%, p <  0.001) and the mean BFFS was significantly lesser (34.4 ± 3.9 vs 97.8 ± 5.9 months, p < 0.001) in the RP group than the definitive ExRT group. However, DMFS, CSS and OS were similar in both groups. In multivariate analysis, being in the RP group significantly increased the risk of BF (p < 0.001). Furthermore, not receiving pelvic lymphatic irradiation in the definitive ExRT group (p = 0.048) and having positive surgical margin in the RP group (p = 0.050) increased the risk of BF. CONCLUSIONS: BF was significantly higher and the mean BFFS was significantly lesser in high-risk prostate cancer patients undergoing RP than definitive ExRT while DMFS, CSS and OS were similar in both treatment groups.

The protective role of jervine against radiation-induced gastrointestinal toxicity.

In this study, we investigated whether jervine (J) could prevent gastrointestinal (GI) side effects of abdominopelvic radiotherapy (RT) in Wistar-Albino female rats. Rats were divided into five groups: control (C), J only (J), J administered at 5 mg/kg/days for 7 days, RT only (RT), J before RT (J + RT), J administered for seven days before RT, J both before and after RT (J + RT + J), and J administered for 7 days before RT and after RT for 3 days. The weights of rats were measured on the 1st, 7th, and 10th days of the study. Rats were sacrificed to obtain tissues from the liver and intestine, which was followed by taking blood samples intracardially. In addition, the tissues were stained with pyruvate dehydrogenase (PDH) immunohistochemically. In our study, J supplementation markedly reduced weight loss, and histopathological, immunohistochemical, biochemical results suggest that J had a protective effect on GI toxicity following RT.

Lycopene in the Prevention of Radiation-Induced Esophagitis.

We aimed to research whether lycopene (L) could prevent radiation-induced acute esophageal toxicity in Wistar albino rats. 60 rats were placed in five groups as follows: control, L, radiotherapy (RT), L before RT (L + RT), and L before and after RT (L + RT + L). 6 mg/kg bw/day L was administered 7 days in the L group, 7 days before RT in the L + RT group, and 7 days before and after in the L + RT + L group. 35 Gy thoracic RT was performed. Serum L levels were measured, and the esophagi were evaluated histopathologically for intraepithelial degenerative changes-necrosis, vacuole formation, inflammation, regeneration-mitosis, and subepithelial bulla formation. L levels were significantly higher in the L receiving groups. All histopathologic results were significantly worse in the RT group than in the none-RT groups. The L + RT and the L + RT + L groups had better results than the RT group. Grade 2-3 degenerative changes-necrosis and vacuole formation were significantly lesser in the L + RT and the L + RT + L groups than those in the RT group. There was a trend toward decreased subepithelial bulla formation and inflammation in the L + RT and the L + RT + L groups compared to the RT group. Regeneration-mitosis was insignificantly lesser in the L + RT and significantly fewer in the L + RT + L groups than that in the RT group.

FDG PET uptake as a predictor of pain response in palliative radiation therapy in patients with bone metastasis.

PURPOSE: To evaluate the relationship between fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) maximum standardized uptake value (SUV(max)) and pain response to radiation therapy (RT) in patients with bone metastasis. MATERIALS AND METHODS: Institutional ethical board approval for the study was obtained, with informed consent, for this prospective study. Thirty-one patients with metastatic bone pain who underwent FDG PET/computed tomography before RT were included. Patients were diagnosed with lung (n = 16), breast (n = 7), stomach (n = 2), and head and neck cancers (n = 3), as well as unknown primary tumor (n = 3). Eighty-five painful metastatic locations with FDG PET scans geographically corresponding to 40 treatment fields were evaluated. Pain scores using visual analog scale or faces pain rating scale and SUV(max) at each location were recorded. All patients were treated with a single fraction 8 Gy RT. Pain scores after RT were assessed at weeks 2, 4, 8, 12, 16, 20, and 24. The pretreatment pain scores and pain response to RT were compared with FDG PET SUV(max) of each location. Pearson correlation, independent t test, one-way analysis of variance, and χ(2) tests were used for statistical analysis. RESULTS: Median SUV(max) and initial pain scores for all locations were 7.2 (range, 1.5-22.5) and 6 (range, 2-8), respectively. Median follow-up time was 24 (range, 3-112) weeks. Median SUV(max) was 4.5 (range, 3.1-7.3), 4.75 (range, 1.5-10.3), 8.8 (range, 5.2-11.9), and 12.1 (range, 7-22.5) for pretreatment pain scores of 2, 4, 6, and 8, respectively. SUV(max) was correlated with pretreatment pain scores (P < .0001). SUV(max) and pretreatment pain scores were also significantly associated with pain response to RT. Median SUV(max) for locations with complete response, partial response, pain progression, and indeterminate response was 5.2, 9.75, 10.8, and 6.4, respectively (P ≤ .001). CONCLUSION: FDG PET SUV(max) correlated with initial pain severity and pain response to RT and can be used as a predictive factor for treatment response in patients with painful bone metastasis treated with palliative RT.

The effects of human amnion membrane-derived mesenchymal stem cells conditioned medium on ionizing radiation-induced premature ovarian failure and endoplasmic reticulum stress-related apoptosis mechanism.

OBJECTIVES: Premature ovarian failure (POF) is defined as the cessation of menstrual periods for at least 4-6 months before the age of 40 years, accompanied by FSH values measuring over 40 IU/L for a month. Radiation therapy, one of the cancer treatment methods, is known to accelerate ovarian aging by reducing and eliminating the number of primordial follicles in the ovarian follicle pool. Ionizing radiation has been reported to cause POF. The objective of this study is to investigate the impact of mesenchymal stem cell conditioned medium (hAMSCs-CM), which is isolated from the amniotic membrane of human placenta, on premature ovarian failure (POF) caused by whole-body irradiation. The study will focus on the ER stress and apoptosis mechanisms in the process. STUDY DISAYN: A POF model was created by exposing rats to 7 Gy of whole-body irradiation. Serum-free hAMSCs-CM were then administered via the tail vein. Follicle count was performed on the ovaries, and immunohistochemistry was used to determine the expressions of GRP78, CHOP, IRE-1, caspase-12, caspase-9, caspase-3. TUNEL was also carried out, and levels of serum FSH, LH, E2, AMH, and oxidative stress marker 8-OHdG were measured. RESULTS AND CONCLUSION: The application of hAMSCs-CM has been found to have a positive impact on follicles affected by radiation. After treatment, the number of primordial, primary, secondary, and graafian follicles, which had previously decreased due to radiation, showed an increase. Furthermore, the number of atretic follicles, which had been increasing due to radiation, showed a decrease. ER is one of the targets affected by ionizing radiation. After ionizing radiation, the expressions of ER stress-related markers and apoptosis markers increased in the ovary. After hAMSCs-CM administration, the expressions of these markers and number of TUNEL-positive cells decreased. Following irradiation, anti-mullerian hormone (AMH) and estradiol (E2) levels decreased, while follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels increased. After administration of hAMSCs-CM, AMH and E2 levels increased, while FSH and LH levels decreased. Amnion membrane-derived mesenchymal stem cell conditioned medium can play a therapeutic role in ionizing radiation-induced premature ovarian failure by reducing endoplasmic reticulum stress and apoptosis.

Human Amnion Membrane-Derived Mesenchymal Stem Cells and Conditioned Medium Can Ameliorate X-Irradiation-Induced Testicular Injury by Reducing Endoplasmic Reticulum Stress and Apoptosis.

Today, infertility affects 15% of couples and half of this rate is due to reproductive problems in men. Radiation-induced damage to the testicles causes sterility depending on the dose. Radiation causes endoplasmic reticulum (ER) stress and ER stress induces apoptosis. In this study, the effect of human amniotic membrane-derived mesenchymal stem cells (hAMSCs) and conditioned medium (hAMSCs-CM) on testicular damage induced by ionizing radiation is aimed to be elucidated through ER stress and apoptosis mechanisms. Six gray scrotal irradiation was used to create a testicular injury model. hAMSCs isolated and characterized with immunofluorescence and flow cytometry, while 2.5 × 105 hAMSCs were transplanted into testis and hAMSCs-CM was applied. Fertility assessment was performed. Expressions of ER stress markers GRP78, Ire1, Chop and Caspase-12, and Caspase-3 were determined. TUNEL was performed. Serum FSH, LH, and testosterone were measured. After hAMSC transplantation and administration of hAMSCs-CM, offsprings were obtained. Seminiferous tubule diameter and seminiferous epithelial height increased. The expression of GRP78, IRE1α, CHOP, Caspase-12, and Caspase-3 decreased. Percentages of tunel positive cells decreased. While FSH and LH levels decreased, testosterone increased. After irradiation, both hAMSCs transplantation and paracrine activity of hAMSCs may have a role in reducing ER stress by suppressing the UPR response. Decrease in FSH and LH and increase in testosterone level after MSCs transplantation may have contributed to the improvement of spermatogenesis. Thus, it can be said that MSCs derived from human amniotic membrane can improve ionized radiation-induced testicular damage by reducing ER stress and apoptosis.

Treatment adherence and outcome in women with inflammatory breast cancer: does race matter?

BACKGROUND: The authors compared treatment adherence rates and outcome in Caucasian and African American patients with inflammatory breast cancer (IBC). METHODS: The records of 55 (25 Caucasian and 30 African American) IBC patients treated with curative intent from 1995 to 2009 were reviewed. All patients received neoadjuvant doxorubicin (Adriamycin) and/or taxane-based chemotherapy, and mastectomy with or without radiotherapy. The median follow-up period for Caucasian and African American patients was similar (39.5 months and 36.1 months, respectively). RESULTS: There was no difference between races in median age, tumor size, grade, and receptor status at diagnosis. The number of patients who completed neoadjuvant chemotherapy, surgery, and radiotherapy did not differ by race (84% of Caucasians vs 86.7% of African Americans) nor did the median length of time to complete trimodality treatment (263 [range, 207-422] days for Caucasians vs 262 [range, 165-371] days for African Americans). There was a trend toward slightly higher pathological complete response rates in Caucasian than African American women (20% in Caucasians vs 6.7% in African Americans, P = .23). Despite slightly better response rates to neoadjuvant chemotherapy, Caucasian patients did not have higher 3-year local control rates (70% in Caucasians vs 64% in African Americans, P = .73). However, there was a trend toward higher 3-year overall survival in Caucasian versus African American patients (73% in Caucasians vs 55% in African Americans, P = .09) and higher distant metastasis-free survival (60% in Caucasians vs 40% in African Americans, P = .19). CONCLUSIONS: This study is among the largest to examine patients with IBC by race. Being Caucasian or African American did not appear to impact treatment adherence. However, African American patients tended to have poorer response to standard treatment and worse outcome than Caucasian patients.

Soy isoflavones in conjunction with radiation therapy in patients with prostate cancer.

Soy isoflavones sensitize prostate cancer cells to radiation therapy by inhibiting cell survival pathways activated by radiation. At the same time, soy isoflavones have significant antioxidant and anti-inflammatory activity, which may help prevent the side effects of radiation. Therefore, we hypothesized that soy isoflavones could be useful when given in conjunction with curative radiation therapy in patients with localized prostate cancer. In addition to enhancing the efficacy of radiation therapy, soy isoflavones could prevent the adverse effects of radiation. We conducted a pilot study to investigate the effects of soy isoflavone supplementation on acute and subacute toxicity (≤6 mo) of external beam radiation therapy in patients with localized prostate cancer. Forty-two patients with prostate cancer were randomly assigned to receive 200 mg soy isoflavone (Group 1) or placebo (Group 2) daily for 6 mo beginning with the first day of radiation therapy, which was administered in 1.8 to 2.5 Gy fractions for a total of 73.8 to 77.5 Gy. Adverse effects of radiation therapy on bladder, bowel, and sexual function were assessed by a self-administered quality of life questionnaire at 3 and 6 mo. Only 26 and 27 patients returned completed questionnaires at 3 and 6 mo, respectively. At each time point, urinary, bowel, and sexual adverse symptoms induced by radiation therapy were decreased in the soy isoflavone group compared to placebo group. At 3 mo, soy-treated patients had less urinary incontinence, less urgency, and better erectile function as compared to the placebo group. At 6 mo, the symptoms in soy-treated patients were further improved as compared to the placebo group. These patients had less dripping/leakage of urine (7.7% in Group 1 vs. 28.4% in Group 2), less rectal cramping/diarrhea (7.7% vs. 21.4%), and less pain with bowel movements (0% vs. 14.8%) than placebo-treated patients. There was also a higher overall ability to have erections (77% vs. 57.1%). The results suggest that soy isoflavones taken in conjunction with radiation therapy could reduce the urinary, intestinal, and sexual adverse effects in patients with prostate cancer.

Instruments for determining clinically relevant fatigue in breast cancer patients during radiotherapy.

BACKGROUND: This study aimed to determine radiotherapy (RT)-related changes in cancer-related fatigue (CRF), using Multidimensional Fatigue Inventory-20 (MFI-20), and fatigue-intensity rating (FIR) instruments at three different timepoints and to identify the optimal thresholds of MFI-20 scores which would correlate with moderate-to-severe fatigue warranting an intervention in breast cancer patients treated with RT. METHODS: Eighty-eight breast cancer patients treated with surgery followed by RT were included in the study. CRF was assessed with both FIR and MFI-20 tools at three different timepoints: within the week prior to RT (pre-RT), last week of RT, and 6 weeks after RT completion (post-RT). Changes in measurements, correlations between measurements and optimal cutpoints of MFI-20 scores were analyzed. RESULTS: While FIR scores significantly changed over time (η2: 0.179), changes in MFI-20 scores were relatively small (η2: 0.076). Comparisons of the last week of RT versus post-RT scores showed small-to-moderate decrease for MFI-20 and FIR. FIR and MFI-20 scores were correlated at all timepoints and most correlated during and after RT (r = 0.525 95%CI 0.346-0.667, r = 0.791 95%CI 0.692-0.860 and r = 0.716 95%CI 0.589-0.808, respectively). Furthermore, the most correlated MFI-20 subscale with FIR was general fatigue (r = 0.603 95%CI 0.442-0.725, r = 0.821 95%CI 0.734-0.881 and r = 0.754 95%CI 0.641-0.835, respectively). Optimal cutpoints of the MFI-20 total scores corresponding to FIR scores ≥ 4 was 43.5 for all timepoints and the MFI total scores corresponding to FIR score ≥ 7 were 53.5, 52.5 and 60.5, respectively. CONCLUSIONS: MFI-20 and FIR scores are highly correlated measures of CRF among breast cancer patients treated with RT. An MFI-20 score of ≥ 43.5 is suggested as a clinically significant score indicating moderate-to-severe fatigue, while an MFI score of ≥ 52.5 is indicative of severe fatigue.

Lycopene in the prevention of gastrointestinal toxicity of radiotherapy.

We conducted a study to investigate if lycopene could reduce gastrointestinal toxicity of abdominal and pelvic radiation in Wistar albino rats. Animals received either a control diet (Group 1), lycopene-supplemented diet (Group 2), control diet and radiation (Group 3), and lycopene-supplemented diet plus radiation (Group 4). In Groups 2 and 4, the rats received 5 mg/kg/day lycopene for 10 days. In Groups 3 and 4, the rats received single fraction 8 Gy abdominal and pelvic radiation (RT) on Day 10. Study endpoints included weight loss, diarrhea, duration of diarrhea, survival, and an oxidative stress marker, plasma level of thiobarbituric acid reactive substance (TBARS). The rats receiving RT only had significantly higher weight loss rate compared to the lycopene plus RT group (P = 0.001). Plasma TBARS levels after RT were also significantly higher in the RT only group compared to lycopene plus RT group (P = 0.001). In conclusion, lycopene supplementation significantly reduced the weight loss and prevented oxidative stress in rats treated with abdominopelvic radiation.

Breast reconstruction and post-mastectomy radiation practice.

PURPOSE: The goal of this study was to explore the perspectives and practice of radiation oncologists who treat breast cancer patients who have had breast reconstruction. METHODS: In 2010, an original electronic survey was sent to all physician members of the American Society of Radiation Oncology, National Cancer Research Institute-Breast Cancer Studies Group in the United Kingdom, Thai Society of Therapeutic Radiology and Oncology, Swiss Society of Radiation Oncology, and Turkish Radiation Oncology Society. We identified factors associated with radiation oncologists who treat breast cancer patients with reconstruction performed prior to radiation and obtained information regarding radiation management of the breast reconstruction. RESULTS: 358 radiation oncologists responded, and 60% of the physicians were from the United States. While 64% of participants agree or strongly agree that breast image affects a woman's quality of life during radiation, 57% feel that reconstruction challenges their ability to deliver effective breast radiation. Compared with other countries, treatment within the United States was associated with a high reconstruction rate (>/= 50% of mastectomy patients) prior to radiation (p < 0.05). Delayed-immediate reconstruction with a temporary tissue expander was more common in the United States than in other countries (52% vs. 23%, p = 0.01). Among physicians who treat patients with tissue expanders, the majority (60%) prefer a moderately inflated implant with 150-250 cc of fluid rather than a completely deflated (13%) or inflated expander (28%) during radiation. Among radiation oncologists who treat reconstructions, 49% never use bolus and 40% never boost a breast reconstruction. United States physicians were more likely than physicians from other countries to boost or bolus the reconstruction irrespective of the type of reconstruction seen in their clinic patients (p < 0.01). CONCLUSIONS: Great variation in practice is evident from our study of radiation treatment for breast cancer patients with reconstruction. Further research on the impact and delivery of radiation to a reconstructed breast may validate some of the observed practices, highlight the variability in treatment practice, and help create a treatment consensus.

Reliability of quantitative ultrasonic assessment of normal-tissue toxicity in breast cancer radiotherapy.

PURPOSE: We have recently reported that ultrasound imaging, together with ultrasound tissue characterization (UTC), can provide quantitative assessment of radiation-induced normal-tissue toxicity. This study's purpose is to evaluate the reliability of our quantitative ultrasound technology in assessing acute and late normal-tissue toxicity in breast cancer radiotherapy. METHOD AND MATERIALS: Our ultrasound technique analyzes radiofrequency echo signals and provides quantitative measures of dermal, hypodermal, and glandular tissue toxicities. To facilitate easy clinical implementation, we further refined this technique by developing a semiautomatic ultrasound-based toxicity assessment tool (UBTAT). Seventy-two ultrasound studies of 26 patients (720 images) were analyzed. Images of 8 patients were evaluated for acute toxicity (<6 months postradiotherapy) and those of 18 patients were evaluated for late toxicity (≥ 6 months postradiotherapy). All patients were treated according to a standard radiotherapy protocol. To assess intraobserver reliability, one observer analyzed 720 images in UBTAT and then repeated the analysis 3 months later. To assess interobserver reliability, three observers (two radiation oncologists and one ultrasound expert) each analyzed 720 images in UBTAT. An intraclass correlation coefficient (ICC) was used to evaluate intra- and interobserver reliability. Ultrasound assessment and clinical evaluation were also compared. RESULTS: Intraobserver ICC was 0.89 for dermal toxicity, 0.74 for hypodermal toxicity, and 0.96 for glandular tissue toxicity. Interobserver ICC was 0.78 for dermal toxicity, 0.74 for hypodermal toxicity, and 0.94 for glandular tissue toxicity. Statistical analysis found significant changes in dermal (p < 0.0001), hypodermal (p = 0.0027), and glandular tissue (p < 0.0001) assessments in the acute toxicity group. Ultrasound measurements correlated with clinical Radiation Therapy Oncology Group (RTOG) toxicity scores of patients in the late toxicity group. Patients with RTOG Grade 1 or 2 had greater ultrasound-assessed toxicity percentage changes than patients with RTOG Grade 0. CONCLUSION: Early and late radiation-induced effects on normal tissue can be reliably assessed using quantitative ultrasound.

A dosimetric comparison of different treatment plans of palliative spinal bone irradiation: analysis of dose coverage with respect to ICRU 50 Report.

BACKGROUND: This study aimed to analyze three-dimensional (3D) dosimetric data of conventional two-dimensional (2D) palliative spinal bone irradiation using different reference points and treatment plans with respect to the International Commission on Radiation Units and Measurements (ICRU) Report 50. METHODS: Forty-five simulation CT scans of 39 patients previously treated for thoraco-lumbar spinal bone metastases were used. Three different treatment plans were created: (1) single posterior field plans using the ICRU reference points (ICRUrps); (2) single posterior field plans using the International Bone Metastasis Consensus Working Party reference points (IBMCrps); (3) two opposed anterior-posterior (AP-PA) field plans using the ICRUrps. The intended dose range for planning target volume (PTV) was 90% to 110% of the prescribed dose for AP-PA field plans. Cumulative dose-volume histograms were generated for each plan, and minimum, maximum and mean doses to the PTV, medulla spinalis, esophagus and intestines were analyzed. RESULTS: The mean percentages of minimum, maximum and mean PTV doses +/- standard deviation were, respectively, 91 +/- 1.3%, 108.8 +/- 1.3% and 99.7 +/- 1.3% in AP-PA field plans; 77.3 +/- 2.6%, 122.2 +/- 4.3% and 99.8 +/- 2.6% in ICRUrp single field plans; and 83.7 +/- 3.3%, 133.9 +/- 7.1% and 108.8 +/- 3.3% in IBMCrp single field plans. Minimum doses of both single field plans were significantly lower (p < 0.001) while maximum doses were significantly higher (p < 0.001) than AP-PA field plans. Minimum, maximum and mean doses were higher in IBMCrp single field plans than in ICRUrp single field plans (p < 0.001). The mean medulla spinalis doses were lower in AP-PA field plans than single posterior field plans (p < 0.001). Maximum doses for medulla spinalis were higher than 120% of the prescribed dose in 22 of 45 (49%) IBMCrp single field plans. Mean esophagus and intestinal doses were higher (p < 0.001) in AP-PA field plans than single field plans, however, less than 95% of the prescribed dose. CONCLUSION: In palliative spinal bone irradiation, 2D conventional single posterior field radiotherapy did not accomplish the ICRU Report 50 recommendations for PTV dose distribution, while the AP-PA field plans did achieve the intended dose ranges with a homogenous distribution and reasonable doses to the medulla spinalis, esophagus and intestines.

Evaluation of skin dose associated with different frequencies of bolus applications in post-mastectomy three-dimensional conformal radiotherapy.

BACKGROUND: The study aimed to calculate chest-wall skin dose associated with different frequencies of bolus applications in post-mastectomy three-dimensional conformal radiotherapy (3D-CRT) and to provide detailed information in the selection of an appropriate bolus regimen in this clinical setting. METHODS: CT-Simulation scans of 22 post-mastectomy patients were used. Chest wall for clinical target volume (CTV) and a volume including 2-mm surface thickness of the chest wall for skin structures were delineated. Precise PLAN 2.11 treatment planning system (TPS) was used for 3D-CRT planning. 50 Gy in 25 fractions were prescribed using tangential fields and 6-MV photons. Six different frequencies of bolus applications (0, 5, 10, 15, 20, and 25) were administered. Cumulative dose-volume histograms were generated for each bolus regimen. The minimum, maximum and mean skin doses associated with the bolus regimens were compared. To test the accuracy of TPS dose calculations, experimental measurements were performed using EBT gafchromic films. RESULTS: The mean, minimum and maximum skin doses were significantly increased with increasing days of bolus applications (p < 0.001). The minimum skin doses for 0, 5, 10, 15, 20, and 25 days of bolus applications were 73.0% +/- 2.0%, 78.2% +/- 2.0%, 83.3% +/- 1.7%, 88.3% +/- 1.6%, 92.2% +/- 1.7%, and 93.8% +/- 1.8%, respectively. The minimum skin dose increments between 20 and 25 (1.6% +/- 1.0%), and 15 and 20 (4.0% +/- 1.0%) days of bolus applications were significantly lower than the dose increments between 0 and 5 (5.2% +/- 0.6%), 5 and 10 (5.1% +/- 0.8%), and 10 and 15 (4.9% +/- 0.8%) days of bolus applications (p < 0.001). The maximum skin doses for 0, 5, 10, 15, 20, and 25 days of bolus applications were 110.1% +/- 1.1%, 110.3% +/- 1.1%, 110.5% +/- 1.2%, 110.8% +/- 1.3%, 111.2% +/- 1.5%, and 112.2% +/- 1.7%, respectively. The maximum skin dose increments between 20 and 25 (1.0% +/- 0.6%), and 15 and 20 (0.4% +/- 0.3%) days of bolus applications were significantly higher than the dose increments between 0 and 5 (0.2% +/- 0.2%), 5 and 10 (0.2% +/- 0.2%), and 10 and 15 (0.2% +/- 0.2%) days of bolus applications (p < or = 0.003). The TPS overestimated the near-surface dose 10.8% at 2-mm below the skin surface. CONCLUSION: In post-mastectomy 3D-CRT, using a 1-cm thick bolus in up to 15 of the total 25 fractions increased minimum skin doses with a tolerable increase in maximum doses.

Lycopene in cancer prevention and treatment.

Dietary intake of lycopene is inversely associated with the risk of many cancers. Preclinical studies show that lycopene has potent in vitro and in vivo antitumor effects, suggesting potential preventive and therapeutic roles for the compound. However, clinical trials with lycopene have only recently been started, and available clinical data preclude firm conclusions with regard to its use in cancer prevention and treatment. Further mechanistic studies and randomized controlled clinical intervention trials with lycopene involving cancer patients are warranted.