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1.
JAMA Oncol ; 3(1): 42-48, 2017 Jan 01.
Article in English | MEDLINE | ID: mdl-27607734

ABSTRACT

IMPORTANCE: Prognostic factors of ipsilateral breast tumor recurrence (IBTR) may change over time following breast-conserving therapy. OBJECTIVE: The EORTC "boost no boost" trial showed that young age and high-grade invasive carcinoma were the most important risk factors for IBTR. This study reanalyses pathological prognostic factors related to IBTR using long-term follow-up. DESIGN, SETTING, AND PARTICIPANTS: Participants included 5569 early-stage breast cancer patients, treated with breast-conserving surgery (BCS) and whole-breast irradiation (WBI), who were randomized between no boost and a 16-Gy boost in the EORTC phase III "boost no boost" trial (1989-1996). A total of 1616 patients with a microscopically complete resection (according to local pathologists), included in the central pathology review, have been analyzed in this study. Median follow-up was 18.2 years. INTERVENTIONS: No further treatment or 16-Gy boost, after BCS and 50-Gy WBI. MAIN OUTCOMES AND MEASURES: Time to ipsilateral breast tumor recurrence (IBTR) as first event. RESULTS: The 20-year cumulative incidence of IBTR in 1616 patients (160 events observed) was 15% (95% CI, 12%-17%). Young age (P < .001) and presence of ductal carcinoma in situ (DCIS) (HR, 2.15; 95% CI, 1.36-3.38; P = .001) were associated with an increased risk of IBTR in multivariable analysis. The cumulative incidence of IBTR at 20 years was 34% (95% CI, 25%-41%), 14% (95% CI, 10%-18%), and 11% (95% CI, 8%-15%), in patients 40 years or younger, 41 to 50 years and 50 years or older, respectively (P < .001). This incidence was 18% (95% CI, 14%-22%) and 9% (95% CI, 6%-12%) for tumors with and without DCIS (P < .001). High-grade tumors relapsed more frequently early during follow-up but the relative effect of age and presence of DCIS seemed stable over time. The boost reduced the 20-year IBTR incidence from 31% (95% CI, 22%-39%) to 15% (95% CI, 8%-21%) (HR, 0.37; 95% CI, 0.22-0.62; P < .001) in high-risk patients (≤50 years with DCIS present). CONCLUSIONS AND RELEVANCE: The association of high-grade invasive tumor with IBTR diminished during follow-up, while the effect of DCIS adjacent to invasive tumor seemed to remain stable. Therefore, patients with high-grade invasive tumors should be monitored closely, especially in the first 5 years, while additional DCIS is an indication for longer follow-up, emphasizing the importance of long-term trial follow-up to estimate absolute effects accurately. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02295033.


Subject(s)
Breast Neoplasms/radiotherapy , Carcinoma, Intraductal, Noninfiltrating/radiotherapy , Neoplasm Recurrence, Local/pathology , Prognosis , Adult , Aftercare , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Carcinoma, Intraductal, Noninfiltrating/drug therapy , Carcinoma, Intraductal, Noninfiltrating/pathology , Carcinoma, Intraductal, Noninfiltrating/surgery , Female , Follow-Up Studies , Humans , Mastectomy, Segmental , Middle Aged , Neoplasm Invasiveness/pathology , Neoplasm Staging , Radiotherapy, Adjuvant
2.
J Stroke Cerebrovasc Dis ; 23(10): 2701-2707, 2014.
Article in English | MEDLINE | ID: mdl-25304721

ABSTRACT

BACKGROUND: Carotid artery vasculopathy is a potential long-term complication after radiotherapy (RT) of the neck, resulting in cerebrovascular events. The underlying pathophysiology is not well understood and early markers are lacking. We aimed to study whether RT of the neck is associated with increase in carotid intima-media thickness (IMT) and stroke in the first 2 years after RT in patients with head and neck cancer (HNC). METHODS: In this prospective cohort study patients treated with RT of the neck were assessed for measurement of IMT before and 2 years after RT. Endpoints were changed in IMT and incidence of first-ever stroke. RESULTS: Between 2003 and 2008 we included 69 patients (median age, 57 years [25%-75% quartile, 51-64 years], median dose of RT 66 Gy [interquartile range, 60-70]) with baseline and follow-up measurement of IMT. Median IMT at baseline and follow-up was .60 and .62 mm (ratio of geometric means 1.01; 95% confidence interval, .96-1.08; P = .63). Four of 69 patients suffered from a stroke. Mean interval from RT to stroke was 6.8 months. CONCLUSIONS: Our study showed no increase of carotid IMT in the first 2 years after RT of the neck in patients treated for HNC. This indicates that the IMT is not a reliable early marker for postirradiation vasculopathy. However, a high rate of strokes was observed. A longer follow-up period is needed to find the starting point of RT-induced vascular changes.


Subject(s)
Carotid Arteries/radiation effects , Carotid Intima-Media Thickness/statistics & numerical data , Head and Neck Neoplasms/radiotherapy , Radiation Injuries/complications , Radiotherapy/adverse effects , Stroke/epidemiology , Aged , Cohort Studies , Female , Humans , Incidence , Male , Middle Aged , Prospective Studies , Radiation Injuries/epidemiology , Risk Factors , Stroke/etiology , Time Factors , Treatment Outcome
3.
BMC Neurol ; 14: 132, 2014 Jun 19.
Article in English | MEDLINE | ID: mdl-24942263

ABSTRACT

BACKGROUND: Successful treatment options for cancer result in more young long-term survivors prone for long-term complications. Carotid artery vasculopathy is a potential long-term complication after radiotherapy of the neck, resulting in cerebrovascular events and probably deficits in cognitive and motor functioning. Better insight into the underlying pathofysiology of radiotherapy induced carotid artery vasculopathy is needed for prognostic purposes and to develop preventive strategies. METHODS/DESIGN: The current study is a prospective cohort study on the long-term cerebral and vascular complications after radiotherapy of the neck, in 103 patients treated for head and neck cancer, included in our study database between 2002 and 2008. Baseline protocol (before radiotherapy) included screening for cerebrovascular risk factors and intima media thickness measurement of carotid arteries by ultrasonography. Follow-up assessment more than 5 years after radiotherapy included screening of cerebrovascular risk factors, cerebrovascular events, neurological examination with gait and balance tests, extensive neuropsychological examination, self-report questionnaires, ultrasonography of the carotid arteries with measurement of intima media thickness and elastography, magnetic resonance imaging of the brain and magnetic resonance angiography of the carotid arteries. DISCUSSION: The current study adds to the understanding of the causes and consequences of long-term cerebral and vascular changes after radiotherapy of the neck. These data will be helpful to develop a protocol for diagnostic and preventive strategies for long-term neurological complications in future head and neck cancer patients with anticipated radiotherapy treatment.


Subject(s)
Carotid Artery Diseases/pathology , Cerebrovascular Disorders/pathology , Head and Neck Neoplasms/complications , Head and Neck Neoplasms/radiotherapy , Radiotherapy/adverse effects , Aged , Carotid Artery Diseases/etiology , Carotid Artery Diseases/psychology , Carotid Intima-Media Thickness , Cerebrovascular Disorders/etiology , Cerebrovascular Disorders/psychology , Cognition Disorders/etiology , Cohort Studies , Female , Follow-Up Studies , Gait Disorders, Neurologic/etiology , Humans , Male , Middle Aged , Neuropsychological Tests , Prospective Studies , Risk Factors , Treatment Outcome
4.
Radiother Oncol ; 100(1): 101-7, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21821304

ABSTRACT

BACKGROUND AND PURPOSE: The EORTC 22881-10882 trial showed that for patients treated with breast conserving therapy (BCT), a 16Gy boost dose significantly improved local control, but increased the risk of breast fibrosis. A model to estimate the risk of ipsilateral breast relapse (IBR) already exists, but now a model has been developed which takes boost treatment into account and is based on centrally reviewed pathology. MATERIALS AND METHODS: A Cox model was developed based on central pathology review data and clinical data of 1603 patients from the EORTC 22881-10882 trial with a median follow-up of 11.5years. From a predefined set of variables, predictors with a maximal effect on 10-year IBR rate >4% were retained in the model. Bootstrap re-sampling was used to assess model calibration and discrimination. The results are presented in the form of a nomogram. RESULTS: Apart from young age and no boost, presence of DCIS adjacent to the invasive tumor was associated with increased risk of IBR (HR 1.96, p=0.001). Patients with high grade invasive tumors were younger than patients with low/intermediate grade (p<0.0001). The nomogram includes histologic grade, DCIS, tumor diameter, age, tamoxifen, chemotherapy, and boost with a concordance probability estimate of 0.68. CONCLUSIONS: The nomogram for predicting IBR 10years after BCT includes seven factors, with young age, presence of DCIS and boost treatment as the most dominant factors. The nomogram estimates IBR and confirms the importance of a boost dose. Combined with a model to predict fibrosis published previously, the nomogram presented here may assist in decision making for individual patients.


Subject(s)
Breast Neoplasms/therapy , Neoplasm Recurrence, Local/epidemiology , Nomograms , Adult , Aged , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Combined Modality Therapy , Female , Humans , Mastectomy, Segmental , Middle Aged , Multivariate Analysis , Proportional Hazards Models
5.
Breast Cancer Res Treat ; 122(3): 711-20, 2010 Aug.
Article in English | MEDLINE | ID: mdl-19859804

ABSTRACT

Many studies correlating gene expression data to clinical parameters assume a linear increase or decrease of the clinical parameter under investigation with the expression of a gene. We have studied genes encoding important breast cancer-related proteins using a model for survival-type data that is based on natural splines and the Cox proportional hazard model, thereby removing the linearity assumption. Expression data of 16 genes were studied in relation to metastasis-free probability in a cohort of 295 consecutive breast cancer patients treated at The Netherlands Cancer Institute. The independent predictive power for disease outcome of the 16 individual genes was tested in a multivariable model with known clinical and pathological risk factors. There is a linear relationship between increasing expression and a higher or lower hazard for distant metastasis for ESR1, ERBB4, VEGF, CCNE2, EZH2, and UPA; for ERBB2, ERBB3, CCND1, CCNE1, EED, CXCR4, CCR7, SDF1, and PAI1 there is no clear increase or decrease; and for EGFR there seems to be a non-linear relation. Multivariable analysis showed that the 70-gene prognosis profile outperforms all the other variables in the model (hazard-rate 5.4, 95% CI 2.5-11.7; P = 0.000018). EGFR-expression seems to have a non-linear relation with disease outcome, indicating that lower but also higher expression of EGFR are associated with worse outcome compared to intermediate expression levels; the other genes show no or a linear relation.


Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Gene Expression Profiling , Proportional Hazards Models , Breast Neoplasms/secondary , Cohort Studies , Female , Humans , Middle Aged , Netherlands , Oligonucleotide Array Sequence Analysis , Prognosis , Regression Analysis
6.
Head Neck ; 29(12): 1102-10, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17786991

ABSTRACT

BACKGROUND: High-resistance heat and moisture exchangers (HMEs) have been reported to increase transcutaneous oxygenation (tcpO(2)) values in laryngectomized individuals and to negatively influence patient compliance. The goal of the present study was to validate earlier published results on short-term transcutaneous oxygenation changes by high-resistance HMEs. METHODS: We conducted a randomized crossover study, monitoring the influence of an HME on tcpO(2) over a 2-hour time interval in 20 subjects. RESULTS: No evidence of an immediate HME effect (95% CI: -14.9-13.3 mm Hg, p = .91), or a time-dependent HME effect (95% CI: -.121 - .172 mm Hg/minute, p = .74), on tcpO(2) was found. After fitting the statistical model without time dependency, again no evidence of HME presence was seen (95% CI: -.5 mm Hg - 3.6 mm Hg, p = .15). CONCLUSION: In contrast to earlier suggestions, there is no evidence of increased tcpO(2) levels by high-resistance HMEs in laryngectomized individuals. Thus, using such HMEs has no added clinical value in this respect.


Subject(s)
Blood Gas Monitoring, Transcutaneous , Hot Temperature , Humidity , Laryngectomy , Tracheostomy/instrumentation , Aged , Aged, 80 and over , Airway Resistance , Cross-Over Studies , Female , Filtration/instrumentation , Humans , Male , Middle Aged , Respiration
7.
Radiother Oncol ; 82(3): 265-71, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17126434

ABSTRACT

PURPOSE: To determine whether the effect of an additional "boost" radiation after breast conservative therapy (BCT) on local control depends on age and evaluate the impact of a treatment policy with a threshold for age. PATIENTS AND METHODS: We used data from EORTC 22881-10882 trial, with median follow-up of 77.4 months. Patients receiving BCT and 50Gy whole breast irradiation were randomized to no boost and 16Gy boost (N=5318). RESULTS: In univariate analysis, a boost reduced local failure by a factor of 2 (P<0.0001). Multivariate analysis showed local control increased with age (P=0.0003). There was no evidence that the relative effect of a boost on local control depends on age (P=0.97) However in younger patients the 5-year local failure was higher, therefore the absolute reduction was greater. If the threshold-age for boost treatment were set at 40 years, 8.4% of the study population would receive a boost, resulting in a 5-year local failure of 6.1% in the study population. Changing the threshold-age to 60 years, 67% of the study population would receive a boost and the 5-year local failure would be reduced to 4.4%. CONCLUSIONS: In younger patients a boost dose resulted in a greater absolute reduction of local failure. The relative risk reduction was however similar for all ages. Applying a treatment policy with a threshold-age of 60 would result in 0.6% increase in local failure in the total study population, while sparing the boost to 1/3 of the patients.


Subject(s)
Breast Neoplasms/radiotherapy , Mastectomy, Segmental , Neoplasm Recurrence, Local/prevention & control , Adult , Age Factors , Antineoplastic Combined Chemotherapy Protocols , Breast Neoplasms/drug therapy , Breast Neoplasms/surgery , Combined Modality Therapy , Cyclophosphamide , Dose-Response Relationship, Radiation , Female , Fluorouracil , Humans , Methotrexate , Middle Aged , Multivariate Analysis , Proportional Hazards Models , Radiotherapy/methods , Radiotherapy Dosage , Risk
8.
Respir Res ; 7: 19, 2006 Jan 31.
Article in English | MEDLINE | ID: mdl-16448568

ABSTRACT

BACKGROUND: In vitro and some in vivo studies suggested that genetic haplotypes may have an impact on beta2-agonist mediated airway responses in asthmatics. Due to strong linkage disequilibrium the single nucleotide polymorphisms (SNPs) in the beta2-adrenoceptor gene result in only a limited number of haplotypes. We intended to evaluate the impact of beta2-adrenoceptor haplotypes on beta2-agonist mediated airway responses and the development of tolerance in mild to moderate asthmatics. METHODS: Patients were genotyped for the part of the beta2-adrenoceptor gene with a known bearing on receptor function and regulation. Cumulative dose response curves of fenoterol versus PD20 methacholine and FEV1 were constructed after 2 week treatment periods with either terbutaline or placebo in a double blind, randomised and cross-over design. Analysis of the dose response curves was based on a repeated measurement analysis of covariance. RESULTS: In our study population comprising 45 asthmatic patients, we found three limited allelic haplotypes, resulting in six different genotypes. Our data support the existence of differences between these six genotypes both in the shape of the dose response relationship of the beta2-adrenoceptor agonist fenoterol as well as in the propensity to develop tolerance for these effects by pre-treatment with terbutaline. However, this could only be substantiated for the endpoint PD20 methacholine. CONCLUSION: Between beta2-adrenoceptor genotypes differences exist both in baseline beta2-agonist induced airway responses as well as in the propensity to develop tolerance during maintenance beta2-agonist therapy. The net differences after two weeks of therapy are, however, of magnitudes that are unlikely to be of clinical significance.


Subject(s)
Adrenergic beta-2 Receptor Agonists , Adrenergic beta-Agonists/administration & dosage , Asthma/genetics , Asthma/metabolism , Lung/metabolism , Receptors, Adrenergic, beta-2/genetics , Asthma/drug therapy , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Female , Fenoterol/administration & dosage , Genetic Predisposition to Disease/genetics , Haplotypes/genetics , Humans , Lung/drug effects , Male , Methacholine Chloride/administration & dosage , Placebo Effect , Polymorphism, Single Nucleotide/genetics
9.
J Pediatr ; 148(1): 62-7, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16423599

ABSTRACT

OBJECTIVE: To evaluate rectal sensitivity in patients with pediatric constipation (PC) and nonretentive fecal soiling (FNRFS) using pressure-controlled distention (barostat). STUDY DESIGN: Thresholds for rectal sensitivity (first sensation, urge to defecate, and pain), and rectal compliance were determined using a barostat. RESULTS: A total of 69 patients with PC (50 males; mean age, 10.9 +/- 2.2 years) and 19 patients with FNRFS (15 males; mean age, 10.0 +/- 1.9 years) were compared with 22 healthy volunteers (HVs) (11 males; mean age, 12.7 +/- 2.6 years). Sensitivity thresholds were not significantly different among the 3 groups. Rectal compliance was increased in 58% of the patients with PC (P < .0001 vs HVs). Rectal compliance did not differ between patients with FNRFS and HVs. Children with PC with abnormal rectal function required significantly larger rectal volumes at urge to defecate. CONCLUSIONS: Increased compliance is the most prominent feature in patients with PC. Because of higher compliance in these children, larger stool volumes are required to reach the intrarectal pressure of the urge to defecate. Children with FNRFS have normal rectal function.


Subject(s)
Constipation/physiopathology , Defecation/physiology , Rectum/physiopathology , Adolescent , Child , Compliance , Female , Humans , Male , Manometry/instrumentation , Manometry/methods , Sensation
10.
Int J Radiat Oncol Biol Phys ; 64(4): 1168-73, 2006 Mar 15.
Article in English | MEDLINE | ID: mdl-16376486

ABSTRACT

PURPOSE: To establish the alpha/beta ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes. METHODS AND MATERIALS: Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED. RESULTS: The estimated alpha/beta ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined. CONCLUSION: With the clinical data currently available, a reliable estimation of the alpha/beta ratio for bladder cancer is not feasible. It seems reasonable to use a conventional alpha/beta ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer.


Subject(s)
Brachytherapy/standards , Radiotherapy Dosage , Urinary Bladder Neoplasms/radiotherapy , Confidence Intervals , Dose Fractionation, Radiation , Dose-Response Relationship, Radiation , Humans , Logistic Models , Radiobiology , Relative Biological Effectiveness , Time Factors
11.
Int J Radiat Oncol Biol Phys ; 61(4): 1011-8, 2005 Mar 15.
Article in English | MEDLINE | ID: mdl-15752880

ABSTRACT

PURPOSE: To study the correlations between the dose distributions in the anorectal region and late GI symptoms in patients treated for localized prostate carcinoma. METHODS AND MATERIALS: Data from a randomized study were analyzed. In this trial, patients were treated with either rectangular or conformal fields with a dose of 66 Gy. Data concerning GI symptoms were collected from questionnaires of 197 patients. The distributions of the anorectal region were projected on maps, and the dose parameters were calculated. The incidences of complaints were studied as a function of the dose-area parameters and clinical parameters, using a proportional hazard regression model. Finally, we tested a series of dose parameters originating from different parts of the anorectal region. RESULTS: Analyzing the total region, only a statistically significant dose-area effect relation for bleeding was found (p < 0.01). Defining subareas, we found effect relations for bleeding, soiling, fecal incontinence, and mucus loss. For bleeding and mucus loss, the strongest correlation was found for the dose received by the upper 70-80% of the anorectal region (p < 0.01). For soiling and fecal incontinence, we found the strongest association with the dose to the lower 40-50% (p < 0.05). CONCLUSION: We found evidence that complaints originate from specific regions of the irradiated lower GI tract. Bleeding and mucus loss are probably related to irradiation of the upper part of the rectum. Soiling and fecal incontinence are more likely related to the dose to the anal canal and the lower part of the rectum.


Subject(s)
Gastrointestinal Diseases/etiology , Prostatic Neoplasms/radiotherapy , Radiation Injuries/complications , Analysis of Variance , Colic/etiology , Defecation/radiation effects , Diarrhea/etiology , Dose-Response Relationship, Radiation , Fecal Incontinence/etiology , Gastrointestinal Hemorrhage/etiology , Humans , Male , Proportional Hazards Models , Rectum/radiation effects
12.
Ann Surg Oncol ; 11(5): 491-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15078633

ABSTRACT

BACKGROUND: The influence of isolated limb perfusion (ILP) on the limb recurrence-free interval (LRFI) and the number of lesions per recurrence was studied for patients with frequently recurring regional in-transit metastases previously managed by excisional surgery. METHODS: All 43 patients who had their first ILP for a third or further limb recurrence were selected from our computer database of 451 patients who underwent therapeutic ILP for recurrent extremity melanoma in our centers. Eighteen patients had resectable and 25 had locally unresectable lesions at the time of ILP. The patients had a total of 269 intervals between treatment of their primary melanoma and last recurrence or last follow-up. Median follow-up was 35 months (interquartile range, 14-64 months). RESULTS: The median LRFI decreases over time from primary melanoma to the third or further recurrence for which ILP was performed (P < 0.001). The median LRFI is 4.7 times longer (95% confidence interval [CI], 2.8-7.9; P < 0.001) after ILP in comparison with the last interval before ILP. Patients with resectable lesions have a median LRFI that is 5.9 times longer (95% CI, 2.7-13; P < 0.001). In all patients, the number of lesions increases by 22% per recurrence number (95% CI, 10%-35%; P = 0.02). At the same recurrence number, patients before ILP have a 2.6-fold higher (95% CI, 1.6-4.5) mean number of lesions than do patients after ILP (P < 0.001). CONCLUSIONS: ILP lengthens the LRFI and decreases the number of lesions per recurrence significantly in patients with repeatedly recurrent limb melanoma. Therefore, ILP could be a valuable adjunct to excisional surgery for in-transit metastases in these patients whose LRFIs tend to shorten over time.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Chemotherapy, Cancer, Regional Perfusion , Melanoma/drug therapy , Melanoma/surgery , Neoplasm Recurrence, Local/prevention & control , Skin Neoplasms/drug therapy , Skin Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Female , Follow-Up Studies , Humans , Male , Melanoma/pathology , Middle Aged , Skin Neoplasms/pathology , Treatment Outcome
13.
Int J Radiat Oncol Biol Phys ; 58(4): 1072-82, 2004 Mar 15.
Article in English | MEDLINE | ID: mdl-15001247

ABSTRACT

PURPOSE: To identify dose-volume parameters related to late rectal bleeding after radiotherapy for prostate cancer. MATERIALS AND METHODS: Clinical complication data from a randomized trial were collected and linked to the individual dose-volume data. In this trial, patients with prostate cancer were treated with either conventional (with rectangular fields) or three-dimensional conformal radiotherapy to a dose of 66 Gy. Patient complaints, including rectal blood loss, were collected for 199 patients, using questionnaires. Absolute and relative dose-volume histograms (DVHs) of the rectal wall (with and without the anal region) were calculated with and without rectal filling. A proportional hazard regression (PHR) model was applied to estimate the probability of any rectal blood loss within 3 years, as a function of several DVH parameters. In a multivariable analysis, dose-volume parameters were tested together with patient- and treatment-related parameters (age, smoking, diabetes, cardiovascular disease, tumor stage, neo-adjuvant androgen deprivation, conformal vs. conventional and rectal bleeding during treatment). RESULTS: The estimated incidence of any and moderate/severe rectal bleeding at 3 years was 33% and 8%, respectively. Differences between the conventional and conformal technique were small and not significant. The analysis of relative DVHs of the rectal wall (with and without the anal region), showed significant (p < 0.01) relations between the irradiated volume and the probability of rectal blood loss within 3 years for dose levels between 25 Gy and 60 Gy. This relationship was shown in subgroups defined by dose-volume cutoff points as well as in the PHR model, in which a continuously rising risk was seen with increasing volumes. For absolute DVHs and DVHs of the rectum including filling, less or no significant results were observed. The most significant volume-effect relation (p = 0.002) was found at 60 Gy for the rectum wall excluding the anal region. The probability of rectal bleeding increased from 10% to 63% when the irradiated rectum volume at 60 Gy increased from 25% to 100%. Other factors. including age, smoking, diabetes, cardiovascular disease, tumor stage, neo-adjuvant androgen deprivation, conformal vs. conventional, rectal bleeding during treatment, rectum length. and whole rectum volume. did not have a significant effect in the multivariable analysis. When controlling for the volumes at 60 Gy, the volumes at lower dose levels (25-55 Gy) were no longer significant (p = 0.5). CONCLUSIONS: For any rectal bleeding within 3 years, an overall incidence of 33% was observed for patients treated to 66 Gy. For this endpoint, a volume-effect relation was found for DVH parameters of the relative rectal wall volume. This relationship appeared to be most significant for the rectum without the anal region and for the higher dose levels (50-60 Gy).


Subject(s)
Gastrointestinal Hemorrhage/etiology , Prostatic Neoplasms/radiotherapy , Radiation Injuries/complications , Rectal Diseases/etiology , Aged , Analysis of Variance , Dose-Response Relationship, Radiation , Follow-Up Studies , Humans , Male , Prognosis , Radiation Dosage , Radiotherapy, Conformal/adverse effects
14.
Radiat Res ; 159(2): 190-8, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12537524

ABSTRACT

During photodynamic therapy (PDT), low oxygenation levels, induced both by oxygen consumption and by vascular occlusion, can lead to an inefficient photochemical reaction that may compromise the efficacy of PDT. In the present studies, tumor oxygenation was measured before, during and after meta-tetrahydroxyphenylchlorin (mTHPC)-mediated PDT of murine RIF1 tumors and human mesothelioma xenografts (H-MESO1). Tumor pO2 was measured in real time with Eppendorf polarography, and the extent of relative hypoxia at specific times was measured by immunohistochemical staining. Significant decreases in median pO2 values, as well as an increase in the number of values below 2.5 mmHg, were seen during and after PDT in RIF1 tumors, although there was a large intertumoral variation. Tumor pO2 values did not change significantly in H-MESO1 tumors. Staining with antibodies against the hypoxia marker EF3 showed significant increases in relative hypoxia after PDT in both tumor types compared with separate groups of untreated controls. Our results are consistent with PDT-induced oxygen depletion (reduced pO2) leading to an increase in relative hypoxia in RIF1 tumors. Extensive necrosis in the H-MESO1 tumors may have prevented the detection of PDT-induced hypoxia using the Eppendorf polarographic needle, whereas immunohistochemistry did reveal increases in relative hypoxia.


Subject(s)
Neoplasms, Experimental/metabolism , Oxygen/metabolism , Photochemotherapy/adverse effects , Animals , Female , Hypoxia/metabolism , Hypoxia/pathology , Immunohistochemistry , Mice , Mice, Inbred C3H , Neoplasm Transplantation , Neoplasms, Experimental/pathology , Partial Pressure , Tumor Cells, Cultured
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