Alterations of nutritional status: impact of chemotherapy and radiation therapy

PPARα Agonism Enhances Immune Response to Radiotherapy While Dietary Oleic Acid Results in Counteraction

PURPOSE

Head and neck cancer (HNC) improvements are stagnant, even with advances in immunotherapy. Our previous clinical trial data show that altered fatty acid (FA) metabolism correlates with outcome. We hypothesized that pharmacologic and dietary modulation of FA catabolism will affect therapeutic efficacy.

EXPERIMENTAL DESIGN

We performed in vivo and in vitro experiments using PPARα agonism with fenofibrate (FF) or high oleic acid diets (OAD) with radiotherapy, generating metabolomic, proteomic, stable isotope tracing, extracellular flux analysis, and flow-cytometric data to investigate these alterations.

RESULTS

FF improved antitumor efficacy of high dose per fraction radiotherapy in HNC murine models, whereas the OAD reversed this effect. FF-treated mice on the control diet had evidence of increased FA catabolism. Stable isotope tracing showed less glycolytic utilization by ex vivo CD8+ T cells. Improved efficacy correlated with intratumoral alterations in eicosanoid metabolism and downregulated mTOR and CD36.

CONCLUSIONS

Metabolic intervention with increased FA catabolism improves the efficacy of HNC therapy and enhances antitumoral immune response.

Prediction of plan adaptation in head and neck cancer proton therapy using clinical, radiographic, and dosimetric features

PURPOSE

Because proton head and neck (HN) treatments are sensitive to anatomical changes, plan adaptation (re-plan) during the treatment course is needed for a significant portion of patients. We aim to predict re-plan at plan review stage for HN proton therapy with a neural network (NN) model trained with patients' dosimetric and clinical features. The model can serve as a valuable tool for planners to assess the probability of needing to revise the current plan.

METHODS AND MATERIALS

Mean beam dose heterogeneity index (BHI), defined as the ratio of the maximum beam dose to the prescription dose, plan robustness features (clinical target volume (CTV), V100 changes, and V100 > 95% passing rates in 21 robust evaluation scenarios), as well as clinical features (e.g., age, tumor site, and surgery/chemotherapy status) were gathered from 171 patients treated at our proton center in 2020, with a median age of 64 and stages from I-IVc across 13 HN sites. Statistical analyses of dosimetric parameters and clinical features were conducted between re-plan and no-replan groups. A NN was trained and tested using these features. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performance of the prediction model. A sensitivity analysis was done to determine feature importance.

RESULTS

Mean BHI in the re-plan group was significantly higher than the no-replan group (p < .01). Tumor site (p < .01), chemotherapy status (p < .01), and surgery status (p < .01) were significantly correlated to re-plan. The model had sensitivities/specificities of 75.0%/77.4%, respectively, and an area under the ROC curve of .855.

CONCLUSION

There are several dosimetric and clinical features that correlate to re-plans, and NNs trained with these features can be used to predict HN re-plans, which can be used to reduce re-plan rate by improving plan quality.

Impact of a ketogenic diet intervention during radiotherapy on body composition: V. Final results of the KETOCOMP study for head and neck cancer patients

PURPOSE

Patients with head and neck cancer (HNC) are at risk of malnutrition, especially during radiochemotherapy. We aimed to study the impact of a ketogenic diet (KD) versus an unspecified standard diet (SD) on body composition and survival in HNC patients undergoing radio(chemo)therapy.

METHODS

As part of a controlled clinical trial, non-metastasized HNC patients were enrolled into either a KD (N = 11) or an SD (N = 21) group between May 2015 and May 2021. Body composition was measured weekly by bioimpedance analysis and analyzed using linear mixed effects models. Overall and progression-free survival was assessed during regular follow-up.

RESULTS

A total of 7 KD and 21 SD patients completed the study and were eligible for comparative analysis. Chemotherapy was significantly associated with declines in all body composition parameters, while the KD had opposing, yet nonsignificant effects. In patients receiving chemotherapy, average weekly reductions of body mass (BM) and skeletal muscle mass (SMM) were 0.9 kg and 0.31 kg in the KD group versus 1.2 kg and 0.57 kg in the SD group, respectively. Patients in the KD group receiving no chemotherapy achieved an average increase of 0.04 kg BM and 0.12 kg SMM per week. After a median follow-up of 42 months (range 6.7-78 months) there were no significant differences in progression-free or overall survival between the groups.

CONCLUSION

The KD may partially counteract the detrimental effects of radiochemotherapy on body composition in HNC patients. This should encourage further research into KDs in frail cancer patient populations and motivate their implementation as complementary therapy for selected patients.

In-situ TiO2-x decoration of titanium carbide MXene for photo/sono-responsive antitumor theranostics

BACKGROUND

Sonodynamic therapy (SDT) has emerged as a noninvasive therapeutic modality that involves sonosensitizers and low-intensity ultrasound. However, owing to the rapid recombination of charge carriers, most of the sonosensitizers triggered poor reactive oxygen species (ROS) generation, resulting in unsatisfactory sonodynamic therapeutic effects.

RESULTS

Herein, a photo/sono-responsive nanoplatform was developed through the in-situ systhesis of TiO2-x on the surface of two-dimensional MXene (titanium carbide, Ti3C2) for photoacoustic/photothermal bimodal imaging-guided near-infrared II (NIR-II) photothermal enhanced SDT of tumor. Because of several oxygen vacancies and smaller size (~ 10 nm), the in-situ formed TiO2-x nanoparticles possessed narrow band gap (2.65 eV) and high surface area, and thus served as a charge trap to restrict charge recombination under ultrasound (US) activation, resulting in enhanced sonodynamic ROS generation. Moreover, Ti3C2 nanosheets induced extensive localized hyperthermia relieves tumor hypoxia by accelerating intratumoral blood flow and tumor oxygenation, and thus further strengthened the efficacy of SDT. Upon US/NIR-II laser dual-stimuli, Ti3C2@TiO2-x nanoplatform triggered substantial cellular killing in vitro and complete tumor eradication in vivo, without any tumor recurrence and systemic toxicity.

CONCLUSION

Our work presents the promising design of photo/sono-responsive nanoplatform for cancer nanotheranostics.

Larger Remaining Stomach Volume Is Associated With Better Nutrition and Muscle Preservation in Patients With Gastric Cancer Receiving Distal Gastrectomy With Gastroduodenostomy

Purpose

Weight loss and deterioration in body composition are observed in patients with gastric cancer (GC) following gastrectomy. This study aimed to investigate the impact of residual stomach volume (RSV) on the nutritional status and body composition of patients with GC treated with distal gastrectomy.

Materials and Methods

In total, 227 patients who underwent minimally invasive distal gastrectomy with Billroth 1 anastomosis for stage I GC between February 2015 and May 2018 were enrolled. Clinicodemographic and laboratory data were collected from the GC registry. The RSV, abdominal muscle area, and subcutaneous/visceral fat areas were measured using computed tomography data.

Results

A larger RSV was associated with a lower decrease in the nutritional risk index (P=0.004) and hemoglobin level (P=0.003) during the first 3 months after surgery, and better recovery at 12 months. A larger RSV demonstrated an advantage in the preservation of abdominal muscle area (P=0.02) and visceral fat (P=0.04) after surgery, as well as less reduction in weight (P=0.02) and body mass index (P=0.03).

Conclusions

Larger RSV was associated with improved nutritional status and better preservation of muscle and fat after distal gastrectomy.

Nutritional Status Impairment Due to Neoadjuvant Chemotherapy Predicts Post-Radical Cystectomy Complications

Background: Radical cystectomy (RC) is the standard treatment for muscle invasive bladder cancer (MIBC). Neoadjuvant chemotherapy (NAC) is associated with improved patient survival. The impact of NAC on nutritional status is understudied, while the association between malnutrition and poor surgical outcomes is well known. This study aims to examine the association between NAC, nutritional status impairment, and post-operative morbidity. Materials and Methods: We included MIBC patients who underwent RC and received NAC from multiple academic centers in Israel. Cross-sectional imaging was used to measure the psoas muscle area and normalized it by height (smooth muscle index, SMI). Pre- and post-NAC SMI difference was calculated (represents nutritional status change). The primary outcomes were post-RC ileus, infection, and a composite outcome of any complication. Logistic regression models were fit to identify independent predictors of the outcomes. Results: Ninety-one patients were included in the study. The median SMI change was −0.71 (−1.58, −0.06) cm²/m². SMI decline was significantly higher in patients with post-RC complications (−18 vs. −203, p < 0.001). SMI change was an independent predictor of all complications, ileus, infection, and other complications. The accuracy of SMI change for predicting all complications, ileus, infection, and other complications was 0.85, 0.87, 0.75, and 0.86, respectively. Conclusions: NAC-related nutritional deterioration is associated with increased risk of complications after RC. Our results hint towards the need for nutritional intervention during NAC prior to RC.

Omega-3 Fatty Acids Supplementation Improve Nutritional Status and Inflammatory Response in Patients With Lung Cancer: A Randomized Clinical Trial

Background and Aims: Clinical studies have reported positive results with omega-3 supplements in patients with cancer. This study aimed to evaluate the efficacy of omega-3 fatty acid supplementation in improving the nutritional status and inflammatory markers of patients with lung cancer.

Methods: In a randomized, double-blind, parallel design trial, 60 patients with lung cancer at nutritional status/risk based on the Nutrition Risk Screening 2002 were randomized to be allocated to two study groups, receiving omega-3 fatty acid supplements [eicosapentaenoic acid (EPA) 1.6 g and docosahexaenoic acid (DHA) 0.8 g] or placebo for 12 weeks. Anthropometric measurements [weight, body mass index (BMI), the circumference of the upper arm, and skinfold thickness of triceps], nutrition-based laboratory indices (hemoglobin, albumin, triglyceride, and cholesterol), and inflammatory markers [C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6)] were measured before and after the intervention as study outcomes.

Results: No significant difference between the two study groups was observed regarding basic characteristics and study outcomes. Compared with placebo group, omega-3 fatty acid supplementation group showed significant higher weight (66.71 ± 9.17 vs. 61.33 ± 8.03, p = 0.021), albumin (4.74 ± 0.80 vs. 4.21 ± 0.77, p = 0.013), and triglyceride (130.90 ± 25.17 vs. 119.07 ± 14.44, p = 0.032). Inflammatory markers were significantly reduced in omega-3 group compared to placebo (CRP 1.42 ± 0.63 vs. 3.00 ± 1.05, p = 0.001 and TNF-α 1.92 ± 0.65 vs. 4.24 ± 1.19, p = 0.001). No significant difference was observed between the two study groups regarding changes in BMI, the circumference of the upper arm, skinfold thickness of triceps, triglyceride, cholesterol, and IL-6 (p > 0.05).

Conclusions: Omega-3 fatty acid supplementation can improve nutritional status and suppress the systemic inflammatory response in patients with lung cancer.

Clinical Trial Registration:www.socialscienceregistry.org, identifier: AEARCTR-0007165.

Micronutrient Food Supplements in Patients with Gastro-Intestinal and Hepatic Cancers

Colorectal carcinogenesis is the second most common cause of mortality across all types of malignancies, followed by hepatic and stomach cancers. Chemotherapy and radiotherapy are key approaches to treating cancer patients, but these carry major concerns, such as a high risk of side effects, poor accessibility, and the non-selective nature of chemotherapeutics. A number of natural products have been identified as countering various forms of cancer with fewer side effects. The potential impact of vitamins and minerals on long-term health, cognition, healthy development, bone formation, and aging has been supported by experimental and epidemiological studies. Successful treatment may thus be highly influenced by the nutritional status of patients. An insufficient diet could lead to detrimental effects on immune status and tolerance to treatment, affecting the ability of chemotherapy to destroy cancerous cells. In recent decades, most cancer patients have been taking vitamins and minerals to improve standard therapy and/or to decrease the undesirable side effects of the treatment together with the underlying disease. On the other hand, taking dietary supplements during cancer therapy may affect the effectiveness of chemotherapy. Thus, micronutrients in complementary oncology must be selected appropriately and should be taken at the right time. Here, the potential impact of micronutrients on gastro-intestinal and hepatic cancers is explored and their molecular targets are laid down.

Metabolomics in cancer research and emerging applications in clinical oncology

Cancer has myriad effects on metabolism that include both rewiring of intracellular metabolism to enable cancer cells to proliferate inappropriately and adapt to the tumor microenvironment, and changes in normal tissue metabolism. With the recognition that fluorodeoxyglucose-positron emission tomography imaging is an important tool for the management of many cancers, other metabolites in biological samples have been in the spotlight for cancer diagnosis, monitoring, and therapy. Metabolomics is the global analysis of small molecule metabolites that like other -omics technologies can provide critical information about the cancer state that are otherwise not apparent. Here, the authors review how cancer and cancer therapies interact with metabolism at the cellular and systemic levels. An overview of metabolomics is provided with a focus on currently available technologies and how they have been applied in the clinical and translational research setting. The authors also discuss how metabolomics could be further leveraged in the future to improve the management of patients with cancer.

Nutritional neuropathy postoesophagogastrectomy

We report a case of a patient who presented complaining of a 1-week history of progressive lower limb weakness and decreased sensation bilaterally suggestive of a peripheral neuropathy, with vague associated symptoms of fluctuating concentration. Clinically, we suspected a Guillain-Barré variant. However, her functioning continued to decline despite intravenous immunoglobulin therapy, and she had normal spinal imaging studies and CSF analysis. Of note, she had a subtotal oesophagectomy and proximal gastrectomy 20 months previously for oesophageal cancer. We found her to be deficient in vitamin D, vitamin E and copper. She was treated with nutritional supplementation of these vitamins and infusion of trace elements, resulting in a gradual improvement in lower limb power, sensation and coordination, as well as improved cognition and mentation. Monthly outpatient neurology follow-up shows continued improvement in symptoms and return towards baseline functioning with regular infusions of nutritional elements and monitoring of blood levels.

MRI- and CT-determined changes of dysphagia / aspiration-related structures (DARS) during and after radiotherapy

Purpose

The concept of dysphagia/aspiration-related structures (DARS) was developed against the background of severe late side effects of radiotherapy (RT) for head and neck cancer (HNC). DARS can be delineated on CT scans, but with a better morphological discrimination on magnetic resonance imaging (MRI). Swallowing function was analyzed by use of patient charts and prospective investigations and questionnaires.

Method

Seventeen HNC patients treated with intensity-modulated radiotherapy (IMRT) ± chemotherapy between 5/2012 – 8/2015 were included. Planning CT (computed tomography) scans and MRIs (magnetic resonance imaging) prior, during 40 Gray (Gy) radiotherapy and posttreatment were available and co-registered to delineate DARS. The RT dose of each DARS was calculated. Five patients were investigated posttreatment for swallowing function and assessed by means of various questionnaires for quality of life (QoL), swallowing, and voice function.

Results

By retrospective comparison of DARS volume, a significant change in four of eight DARS was detected over time. Three increased and one diminished. The risk of posttreatment dysphagia rose by every 1Gy above the mean dose (D mean) of RT to DARS. 7.5 was the risk factor for dysphagia in the first 6 months, reducing to 4.7 for months 6-12 posttreatment. For all five patients of the prospective part of swallowing investigations, a function disturbance was detected. These results were in contrast to the self-assessment of patients by questionnaires. There was neither a dose dependency of D mean DARS volume changes over time nor of dysphonia and no correlation between volume changes, dysphagia or dysphonia.

Conclusion

Delineation of DARS on MRI co-registered to planning CT gave the opportunity to differentiate morphology better than by CT alone. Due to the small number of patients with complete MRI scans over time, we failed to detect a dose dependency of DARS and swallowing and voice disorder posttreatment.

Post cricoid tumours; a limiting factor for percutaneous endoscopic gastrostomy insertion in cancer patients: Results from a tertiary care hospital

BACKGROUND AND STUDY AIMS

The aim of this study was to review all episodes of PEG insertion in patients with head and neck cancer (HNC) at a cancer specialist centre.

PATIENTS AND METHODS

Using a structured data extraction form, we abstracted patients' demographic data and clinical information including the primary site of tumour, TNM staging, whether PEG tube was inserted successfully, any complications resulting from PEG tube insertion and duration the tube was in place.

RESULTS

We identified a total of 339 HNC patients who had received at least one attempted PEG tube insertion. The mean age of patients was 49.5 ± 14.5 years and 66% (n: 233/339) were males. 151/ 339 (44.5%) patients had a tumour in the pharynx and nasopharynx, 103/ 339 (30.4%) in oral cavity, 81/ 339 (23.9%) in post-cricoid region and 4 (1.1%) of the patients had a laryngeal carcinoma. Histopathologically, most tumours (75.8%) were squamous cell carcinoma presenting at a T4 (52.6%), N0 (38.3%) and M0 (91.7%) stage. PEG tube was successfully inserted in 303/339 (89.4%) patients. There were 36 PEG failures; 24 (66.6%) in postcricoid and laryngeal tumours, 8 (22.3%) in pharynx/nasopharynx and 4 (11.1%) in oral cavity tumours. Of the 81 patients with post-cricoid tumour, PEG tube was successfully inserted in 57/ 81 (70.3%) of the patients. Age, gender or T stage of the tumour was not found to be statistically significant predictors of PEG failure. The only significant factor was presence of post-cricoid or laryngeal tumours that increased the risk of PEG failure 12 times (95% confidence interval: 3.4 to 42.3).

CONCLUSION

PEG tube should be used as a first line feeding option in patients with all type of head and neck cancers, however, the attending clinicians should have this foresight of higher failure rates in patients with post-cricoid tumour.

Chemotherapy-induced muscle wasting: association with NF-κB and cancer cachexia

A compounding feature of greater than 50% of all cancers is the high incidence of the cachexia syndrome, a complex metabolic disorder characterized by extreme weight loss due mainly to the gross depletion of skeletal muscle tissue. Although studies into the cause of cancer cachexia has spanned over multiple decades, little is known about the effects of various cancer treatments themselves on cachexia. For example, chemotherapy agents induce side effects such as nausea and anorexia, but these symptoms do not fully account for the changes seen with cancer cachexia. In this study we examine the effects of chemotherapeutic compounds, specifically, cisplatin in the colon-26 adenocarcinoma model of cancer cachexia. We find that although cisplatin is able to reduce tumor burden as expected, muscle wasting in mice nevertheless persists. Strikingly, cisplatin alone was seen to regulate muscle atrophy, which was independent of the commonly implicated ubiquitin proteasome system. Finally, we show that cisplatin is able to induce NF-κB activity in both mouse muscles and myotube cultures, suggesting that an additional side effect of cancer treatment is the regulation of muscle wasting that may be mediated through activation of the NF-κB signaling pathway.

Impact of Hospitalization on the Nutritional Status of Cancer Patients

This study was undertaken to examine the influence of hospitalization on the nutritional status of cancer patients. We examined 126 patients consecutively admitted to the Istituto Nazionale Tumori of Milan. At admission, all patients underwent standard evaluations, including actual weight, percentage weight loss, arm circumference, triceps skinfold, serum proteins, serum albumin, total iron binding capacity, cholinesterase and peripheral lymphocytes. Finally, from all patients a 24-h dietary recall was obtained, in order to calculate calorie and protein intake. All the patients underwent another evaluation after 1 week of hospitalization; after 2 weeks only 37 of them were evaluated again, since some were operated, some were treated with radio-chemotherapy, some were discharged or had died. Results showed that after one week of hospitalization some variables were significantly altered, such as arm circumference in male patients, serum proteins, cholinesterase, total iron binding capacity, peripheral lymphocytes, calorie and protein intake. A significant weight loss was seen after 2 weeks. The reduced calorie and protein assumption was correlated with depletion of some of the nutritional variables (body weight, arm circumference in males, total iron binding capacity, serum albumin, cholinesterase, lymphocytes). Our data show that hospitalization plays an important role in deterioration of nutritional status in our patient population, and this problem is generally overlooked by the clinicians primarily involved in the care of cancer patients.

Nutritional Support in Patients with Cancer of the Esophagus: Impact on Nutritional Status, Patient Compliance to Therapy, and Survival

AIMS AND BACKGROUND

The multimodal approach to patients with esophageal squamous cell carcinoma often includes polychemotherapy combined with radiation therapy. Cancer dysphagia and drug-related anorexia, mucositis and vomiting can all lead to malnutrition. The aim of this study was to analyze the impact of the administration of enteral nutrition (EN) on the patient's nutritional status, tolerance of chemotherapy and radiotherapy, and final oncological outcome.

METHODS

Fifty esophageal cancer patients who were to be submitted to chemotherapy (days 1-4 5-fluorouracil (FU) 1 g/m2/day and cisplatin (CDDP) 100 mg/m2/day 1) for two cycles plus radiotherapy (31 Gy) were referred to the Nutrition Support Unit prior to any therapy due to their malnourished status. Twenty-nine dysphagic patients received nutrition via tube (37 kcal/kg/day + 2.0 g proteins/kg/day for 34 days), while 21 others who were not dysphagic were given a standard oral diet (SD). The patients who received EN had a more severe weight loss than the SD patients (16.8% vs 12.8%, P <0.02).

RESULTS

The dose of administered EN represented 86% of the planned support, and 70% of the nutritional therapy was administered in the home setting. Administration of EN support resulted in stable body weight and unchanged levels of visceral proteins, while SD patients had a decrease in body weight, total proteins and serum albumin (P <0.01). There was no difference between the two groups in terms of tolerance and response to cancer therapy, suitability for radical resection and median survival (9.5 months).

CONCLUSIONS

EN in patients with cancer of the esophagus undergoing chemotherapy and radiotherapy is well tolerated, feasible even in the home setting, prevents further nutritional deterioration and achieves the same oncological results in dysphagic patients as those achieved in non-dysphagic patients.

Use of regularized principal component analysis to model anatomical changes during head and neck radiation therapy for treatment adaptation and response assessment

PURPOSE

To develop standard (SPCA) and regularized (RPCA) principal component analysis models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients and assess their potential use in adaptive radiation therapy, and for extracting quantitative information for treatment response assessment.

METHODS

Planning CT images of ten H&N patients were artificially deformed to create "digital phantom" images, which modeled systematic anatomical changes during radiation therapy. Artificial deformations closely mirrored patients' actual deformations and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and synthetic CBCTs (i.e., digital phantoms) and between pCT and clinical CBCTs. Patient-specific SPCA and RPCA models were built from these synthetic and clinical DVF sets. EigenDVFs (EDVFs) having the largest eigenvalues were hypothesized to capture the major anatomical deformations during treatment.

RESULTS

Principal component analysis (PCA) models achieve variable results, depending on the size and location of anatomical change. Random changes prevent or degrade PCA's ability to detect underlying systematic change. RPCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes and is therefore more successful than SPCA at capturing systematic changes early in treatment. SPCA models were less successful at modeling systematic changes in clinical patient images, which contain a wider range of random motion than synthetic CBCTs, while the regularized approach was able to extract major modes of motion.

CONCLUSIONS

Leading EDVFs from the both PCA approaches have the potential to capture systematic anatomical change during H&N radiotherapy when systematic changes are large enough with respect to random fraction-to-fraction changes. In all cases the RPCA approach appears to be more reliable at capturing systematic changes, enabling dosimetric consequences to be projected once trends are established early in a treatment course, or based on population models.

Cisplatin-Impaired Adipogenic Differentiation of Adipose Mesenchymal Stem Cells1

Adipose tissue-derived mesenchymal stem cells (ADSCs) are derived from adipose tissue and can be induced in vitro to differentiate into osteoblasts, chondroblasts, myocytes, neurons, and other cell types. Cisplatin is a commonly used chemotherapy drug for cancer patients. However, the effects of cisplatin on ADSCs remain elusive. This study found that a high concentration of cisplatin affects the viability of ADSCs. First, the IC50 concentration of cisplatin was evaluated. Proliferation of ADSCs, as assessed by the XTT method, decreased immediately after treatment with various concentrations of cisplatin. ADSCs maintained mesenchymal stem cell surface markers after cisplatin treatment, as determined by flow cytometry. Upon differentiation by adding specific reagents, a significant decrease in adipogenic differentiation (by Oil red O staining) and osteogenic differentiation (by Alizarin red staining), and significant chondrogenic differentiation (by Alcian blue staining) were found after cisplatin treatment. Quantitative RT-PCR was also used in evaluating expression of specific genes to confirm differentiation. Finally, ADSCs from one donor who had received cisplatin showed significantly decreased adipogenic differentiation but increased osteogenic differentiation compared with ADSCs derived from one healthy donor. In conclusion, cisplatin affects the viability, proliferation, and differentiation of ADSCs both in vitro and in vivo via certain signaling pathways, such as p53 and Fas/FasL. The differentiation abilities of ADSCs should be evaluated before their transplantation for repairing cisplatin-induced tissue damage.

Should Patients Undergoing Chemotherapy and Radiotherapy Be Prescribed Antioxidants?

In September 2005, CA: A Cancer Journal for Clinicians published a warning by Gabriella D’Andrea, MD, against the concurrent use of antioxidants with radiotherapy and chemotherapy. However, several deficiencies of the CA article soon became apparent, not least the selective omission of prominent studies that contradicted the author’s conclusions. While acknowledging that only large-scale, randomized trials could provide a valid basis for therapeutic recommendations, the author sometimes relied on laboratory rather than clinical data to support her claim that harm resulted from the concurrent use of antioxidants and chemotherapy. She also sometimes extrapolated from chemoprevention studies rather than those on the concurrent use of antioxidants per se. The article overstated the degree to which the laboratory data diverged in regard to the safety and efficacy of antioxidant therapy: in fact, the preponderance of data suggests a synergistic or at least harmless effect with most high-dose dietary antioxidants and chemotherapy. The practical recommendations made in the article to avoid the general class of antioxidants during chemotherapy are inconsistent, in that if antioxidants were truly a threat to the efficacy of standard therapy, antioxidant-rich foods, especially fruits and vegetables, ought also be proscribed during treatment. Yet no such recommendation is made. Furthermore, the wide-scale use by both medical and radiation oncologists of synthetic antioxidants (eg, amifostine) to control the adverse effects of cytotoxic treatments is similarly overlooked. In sum, this CA article is incomplete: there is far more information available regarding antioxidant supplements as an appropriate adjunctive cancer therapy than is acknowledged. Patients would be well advised to seek the opinion of physicians who are adequately trained and experienced in the intersection of 2 complex fields, that is, chemotherapeutics and nutritional oncology. Physicians whose goal is comprehensive cancer therapy should refer their patients to qualified integrative practitioners who have such training and expertise to guide patients. A blanket rejection of the concurrent use of antioxidants with chemotherapy is not justified by the preponderance of evidence at this time and serves neither the scientific community nor cancer patients.

Effects of nutritional intervention in head and neck cancer patients undergoing radiotherapy: A prospective randomized clinical trial

Head and neck malignant tumors have numerous locations of the disease. After patients receive radiotherapy, their nutritional status is very poor, thus the curative effect is unsatisfactory. The aims of the present study were to investigate and analyze the nutritional status of patients with head and neck cancer undergoing radiotherapy (RT) in order to provide positive nutrition intervention for assisting the radiotherapy effect. A total of 40 patients with head and neck cancer were selected using a method of subjective global assessment (SGA) to assess nutritional status, including calorie intake and energy expenditure. In a randomized, controlled study, 20 patients received intensive dietary counseling and nutritional therapy (G1) and 20 received regular dietary as controls (G0) preradiotherapy and postradiotherapy. The primary endpoint was calorie intake and energy expenditure. The secondary endpoint was SGA rating with nutritional therapy. At the end of RT, energy intake showed a net increase in G1 (1,691±301 kcal) compared with that in G0 (1,066±312 kcal) (P<0.05); energy expenditure increased in G1 (1,673±279 kcal) compared with G0 (1,490±298 kcal) (P<0.05). The prevalence of severe malnutrition following radiotherapy was significantly different between the two study groups (10 patients in G0 and 4 patients in G1; P<0.05). The number of the normal malnutrition patients postRT in G0 decreased from 4 to 2 and conversely, in G1 it increased from 3 to 6 (P<0.05). In conclusion, patients with head and neck cancer were most malnutritioned, which impacted on clinical outcome. Timely nutritional intervention can effectively prevent weight loss and muscle wasting. Additionally, it may improve quality of life by decreasing the frequency of severe malnutrition.

Restricting carbohydrates to fight head and neck cancer-is this realistic?

Head and neck cancers (HNCs) are aggressive tumors that typically demonstrate a high glycolytic rate, which results in resistance to cytotoxic therapy and poor prognosis. Due to their location these tumors specifically impair food intake and quality of life, so that prevention of weight loss through nutrition support becomes an important treatment goal. Dietary restriction of carbohydrates (CHOs) and their replacement with fat, mostly in form of a ketogenic diet (KD), have been suggested to accommodate for both the altered tumor cell metabolism and cancer-associated weight loss. In this review, I present three specific rationales for CHO restriction and nutritional ketosis as supportive treatment options for the HNC patient. These are (1) targeting the origin and specific aspects of tumor glycolysis; (2) protecting normal tissue from but sensitizing tumor tissue to radiation- and chemotherapy induced cell kill; (3) supporting body and muscle mass maintenance. While most of these benefits of CHO restriction apply to cancer in general, specific aspects of implementation are discussed in relation to HNC patients. While CHO restriction seems feasible in HNC patients the available evidence indicates that its role may extend beyond fighting malnutrition to fighting HNC itself.

A prospective study on the radiation therapy associated changes in body weight and bioelectrical standardized phase angle

BACKGROUND & AIMS

Standardized phase angle (SPA) is a value derived from bioelectrical impedance phase angle analysis and has been recognized as marker of nutritional risk and clinical status of cancer patients. This study aimed to evaluate the changes in SPA during radiation therapy of cancer patients and identify possible nutritional and clinical determinants of these changes.

METHODS

Nutritional assessment was performed before the initiation and at the end of the radiotherapy. It included anthropometrics and bioelectrical impedance analysis. A generalized linear mixed model was used to evaluate the effects of selected independent variables on the changes in standardized phase angle.

RESULTS

A total of 104 patients entered the study and those with complete information were included in the analysis (n = 62). Most patients (61%) were at clinical stage I and II, the most prevalent irradiation site was the pelvis (39%) and 98% were well nourished or overweight. According to the regression analysis, changes in body weight and irradiation at head and neck/upper abdomen and thorax were associated with standardized phase angle modifications during radiotherapy. Clinical stage and radiation dose were not associated with changes in standardized phase angle. Compared to baseline values, for every 1 kg weight reduction during the radiation therapy, the standardized phase angle also decreased by 0.107 (p < 0.0001).

CONCLUSIONS

In well nourished or overweight patients, weight loss during radiation therapy is closely associated with decrease in standard phase angle.

Evaluating positional accuracy using megavoltage cone-beam computed tomography for IMRT with head-and-neck cancer

Accurate dose delivery is essential for the success of intensity-modulated radiation therapy (IMRT) for patients with head-and-neck (HN) cancer. Reproducibility of IMRT dose delivery to HN regions can be critically influenced by treatment-related changes in body contours. Moreover, some set-up margins may not be adaptable to positional uncertainties of HN structures at every treatment. To obtain evidence for appropriate set-up margins in various head and neck areas, we prospectively evaluated positional deviation (δ values) of four bony landmarks (i.e. the clivus and occipital protuberance for the head region, and the mental protuberance and C5 for the neck region) using megavoltage cone-beam computed tomography during a treatment course. Over 800 δ values were analyzed in each translational direction. Positional uncertainties for HN cancer patients undergoing IMRT were evaluated relative to the body mass index. Low positional accuracy was observed for the neck region compared with the head region. For the head region, most of the δ was distributed within ± 5 mm, and use of the current set-up margin was appropriate. However, the δ values for the neck region were within ± 8 mm. Especially for overweight patients, a few millimeters needed to be added to give an adequate set-up margin. For accurate dose delivery to targets and to avoid excess exposure to normal tissues, we recommend that the positional verification process be performed before every treatment.

Factors Affecting Outcomes of Alternating Chemoradiotherapy for Nasopharyngeal Cancer

Objective:

Nasopharyngeal cancer (NPC) is radiosensitive and chemosensitive. We evaluated the efficacy of alternating chemoradiotherapy in patients with advanced NPC.

Methods:

Alternating chemoradiotherapy was initiated in 30 patients with NPC, and 27 patients with cancer stages II (n = 6), III (n = 8), IVA (n = 9), and IVB (n = 4) were retrospectively analyzed. Chemotherapy was initially administered followed by radiotherapy, and chemotherapy, radiotherapy, and chemotherapy were alternately administered. Of the 27 patients, 22 patients received cisplatin (50 mg/m2/day, days 6 and 7) and 5-fluorouracil (5-FU; 800 mg/m2/day, days 1-5), whereas 5 patients received carboplatin (AUC 4-5, day 6) and 5-FU.

Results:

Of the 27 patients, 19 (70%) received 3 chemotherapy courses. The total duration of alternating chemoradiotherapy was 81 to 101 days (median, 90 days). At a median follow-up of 53 months, the 5-year progression-free survival (PFS) was 71%. Multivariate analysis showed that weight loss and the number of chemotherapy courses had a significant effect on PFS.

Conclusion:

Alternating chemoradiotherapy led to similar or higher survival rates compared with concurrent chemoradiotherapy, which was characterized by good compliance and adaptable intensity.

Changes in plasma amino acids during conditioning therapy prior to bone marrow transplantation: Their relevance to antioxidant status

Bone marrow transplant (BMT) recipients undergo a bimodal regimen of conditioning therapy, the precise prescription being dependent upon the primary disease of the individual patient. Generally, this treatment consists of chemotherapy and total body irradiation prior to transplantation, although the latter may or may not be included in the regimen. We have investigated amino acid metabolism and oxidant status in in a small series of BMT recipients before and after conditioning therapy.Plasma amino acids were measured by HPLC on 10 BMT recipients prior to commencing conditioning therapy, and again one week later before transplantation. In addition some general nutritional parameters and antioxidant components were measured. A marked decrease in the plasma concentration of a number of amino acids, especially those concerned with antioxidants, was observed over the 7 days of conditioning therapy.There is also a significant reduction in antioxidant capability, as reflected by measurements of glutathione and erythrocyte glutathione peroxidase (GSHPx), which may have an influence upon post-transplant recovery and graft function. Such a reduction in antioxidant concentrations may also have an influence upon the erythrocyte and platelet support required post-grafting.The data presented in this paper adds to the evidence for the conditional essentiality of some amino acids such as taurine and glutamine, and may support the case for specific antioxidant intervention treatment prior to, and/or after conditioning therapy together with monitoring antioxidant status during the post-grafting period.

Validation of a surgical technique for rat intestinal irradiation: potential side effects prevention by dietary grape phenolics

AIMS

This study evaluates and defines the histological and biochemical consequences of irradiation on the Hauer-Jensen intestinal model and investigates the potential effects of dietary polyphenols.

MAIN METHODS

Sprague-Dawley rats were orchiectomized, and an ileal loop was transposed to the left part of the scrotum, then irradiated 2 weeks after surgery with a single dose of 21 Gy (4.49 Gy/min). Four groups of rats received either phenolic extracts from grape seeds (EGS) and from red wine (ACYS, EGT), or pure quercetin 3-O-β-glucoside (Q3G), for 5 days before the irradiation and were sacrificed 2 weeks after. Antioxidant enzyme activities, i.e. superoxide dismutase (SOD) and glutathione peroxidase activity (GSHPx), and oxidative markers such as myeloperoxidase activity (MPO) and thiobarbituric acid reactive substances (MDA) were measured as well as cytokine-induced neutrophil chemoattractant level (CINC-1), a chemokine involved in inflammation.

KEY FINDINGS

Irradiated rats exhibited a high radiation injury score (RIS) with a thickened serosa, mucosal loss and ulceration, and epithelial atypicality. Intestinal MPO activity and CINC-1 concentration were significantly increased in irradiated animals (60 and 66 %, respectively). Higher plasma MDA levels (58 %) and SOD activity (32 %) were accompanied by a reduced GSHPx activity (79 %). However, feeding phenolic extracts remarkably reduced levels of blood SOD activity (34 % on average), intestinal CINC-1 (25-75 % range) and MPO activity (36-84 %). Except for Q3G, phenolics preserved the intestinal structure.

SIGNIFICANCE

These findings show that irradiation triggers an inflammation, and an oxidative stress by disturbing the pro-oxidant/antioxidant balance and indicate that phenolics supply exerts preventive effects against radio-induced intestinal impairment.

Biological mechanism and clinical effect of protein-bound polysaccharide K (KRESTIN(®)): review of development and future perspectives

The mechanism of action of protein-bound polysaccharide K (PSK; KRESTIN(®)) involves the following actions: (1) recovery from immunosuppression induced by humoral factors such as transforming growth factor (TGF)-β or as a result of surgery and chemotherapy; (2) activation of antitumor immune responses including maturation of dendritic cells, correction of Th1/Th2 imbalance, and promotion of interleukin-15 production by monocytes; and (3) enhancement of the antitumor effect of chemotherapy by induction of apoptosis and inhibition of metastasis through direct actions on tumor cells. The clinical effectiveness of PSK has been demonstrated for various cancers. In patients with gastric or colorectal cancer, combined use of PSK with postoperative adjuvant chemotherapy prolongs survival, and this effect has been confirmed in multiple meta-analyses. For small-cell lung carcinoma, PSK in conjunction with chemotherapy prolongs the remission period. In addition, PSK has been shown to be effective against various other cancers, reduce the adverse effects of chemotherapy, and improve quality of life. Future studies should examine the effects of PSK under different host immune conditions and tumor properties, elucidate the mechanism of action exhibited in each situation, and identify biomarkers.

Evaluation of the radiobiological impact of anatomic modifications during radiation therapy for head and neck cancer: can we simply summate the dose?

BACKGROUND AND PURPOSE

Adaptive strategies in radiotherapy (RT) require the knowledge of the total dose given to every organ of the body. Because of anatomical changes and setup errors non-rigid registration is necessary to map the different dose fractions to a common reference. This study evaluates practically if the accumulation of all of these registered dose fractions must take radiobiology into account in a classical clinical setting.

MATERIALS AND METHODS

Ten patients with head and neck tumors treated by chemo-RT were used. Contrast-enhanced CT scans were acquired prior and during RT following delivery of mean doses of 14.2, 24.5, 35.0 and 44.9 Gy and the planned pre-treatment helical tomotherapy sinograms were applied on the per-treatment CTs to create a series of per-treatment dose distributions corresponding to each per-treatment CT image. In order to calculate the cumulative dose distribution, the per-treatment dose maps were non-rigidly deformed by using the deformation map computed by a non-rigid registration. The deformed dose maps were then summed in two ways: one while taking radiobiology into account and one without. These two strategies were compared using clinical surrogates in the target volumes (TV) and in surrounding organs at risk (OAR).

RESULTS

The differences between the strategies, while statistically significant (p<0.05), are clinically irrelevant. In the OARs, the mean differences stay in the 0.01-0.07 Gy range for the total dose. In the targets, all mean differences stay in the 0.001-0.012 Gy range. However, some local high difference spots appear leading to punctual errors as high as 2.5 Gy.

CONCLUSION

If using current radiotherapy practices and clinical recommendations based on dose surrogates computed globally on OARs and TVs, one does not need to take radiobiological effects into account while accumulating total dose as these lead to very small differences compared to a simple accumulation technique consisting of a linear sum of the dose fractions. However, care must be taken if other adaptive strategies, based on local rather than global information, are used.

The effect of continuous enteral tube feeding on various nutritional parameters in patients with disseminated malignant melanoma during intensive chemotherapy

In a prospective study the effect of continuous enteral tube feeding was evaluated on various nutritional parameters in patients with disseminated malignant melanoma during 13 chemotherapy courses employing bleomycin, DTIC, vindesine and actinomycin D. The patients received a quantity of calories according to their pretreatment intake, but complete metabolic equilibrium could not be obtained during chemotherapy. Although the weight/height index remained unchanged, a decrease of serum albumin and prealbumin level occurred during all 13 treatment courses. Transferrin level decreased during 11 of these courses and cholinesterase level during 12. Triceps skinfold thickness and arm muscle circumference diminished equally. Serum prealbumin was the first nutritional parameter to fall during chemotherapy and seems to be a very sensitive indicator of the occurrence of nutritional imbalance. The plasma vitamin C level was low before treatment while during treatment both vitamin C and vitamin A level fell quickly even though the nutritional intake of these vitamins was adequate. We conclude that continuous enteral tube feeding, which is a feasible method of feeding, can to some extent fulfill the nutritional needs of patients treated with intensive chemotherapy.

Sensitivity of intensity modulated proton therapy plans to changes in patient weight

PURPOSE

A retrospective study to investigate the sensitivity of intensity modulated proton therapy (IMPT) to changes in body weight occurring during the course of radiotherapy for patients treated in the sacral region.

MATERIALS AND METHODS

During therapy, important weight gain and loss were observed for two patients treated to para-spinal tumors, which resulted in both patients being re-scanned and re-planned. Both patients were treated as part of their therapy, with a narrow-angle IMPT (NA-IMPT) plan delivering a 'dose hole' around the cauda equina (CE), which was mainly formed through modulation of Bragg peaks in depth. To investigate the impact of these weight changes on the proton range and delivered dose, the nominal fields were re-calculated on the new CT data sets. Results were analyzed by comparing these new plans with those originally delivered and by calculating changes in range and delivered doses in target volumes and normal tissues.

RESULTS

Maximum differences in proton range in the CE region of up to +8 mm and -13 mm, respectively, for the patient who gained weight and for the patient who lost weight, increased the maximum dose to the CE by only 2%. This indicates that both IMPT plans were relatively insensitive to substantial range uncertainties. Even greater differences in range (16 mm) in the planning target volume only slightly affected its dose homogeneity (differences in V(90%) of 6% in the worst case). Nevertheless, some large undesired local dose differences were observed.

CONCLUSIONS

We demonstrated, that, at least for the two analyzed cases, NA-IMPT plans are less sensitive to weight variations than one may expect. Still, we would advise to calculate new plans in case of substantial change in weight for patients treated in the sacral region, primarily due to the presence of new hot/cold area.

A study on adaptive IMRT treatment planning using kV cone-beam CT

BACKGROUND AND PURPOSE

Changes in tumor size during the course of radiotherapy warrant performing adaptive radiotherapy (ART). This work investigates the feasibility and usefulness of acquiring on-board cone-beam CT (CBCT) for ART for patients with bulky head and neck tumors treated with IMRT and for prostate patients with potentially significant target position variations during the treatment course.

MATERIALS AND METHODS

A phantom designed for CT quality assurance was used to compare the dosimetric and geometric accuracy between conventional CT and CBCT from a linear accelerator's on-board imager. Patient planning CT and CBCT images were acquired before treatment and at mid-course. The IMRT plans made on the CT were applied to the CBCT and dose-volume histograms were calculated.

RESULTS

In both phantom and patient studies, the dose-volume histograms (DVHs) based on CBCT images were in excellent agreement with DVHs based on planning CT images. Minimum, maximum and mean doses agreed very well. In a patient study, doses for targets and normal tissues from the same IMRT plans calculated on CBCT images agreed within 1-3% with those calculated on planning CT images.

CONCLUSIONS

CBCT images can be used to accurately predict dosimetric results. It is feasible to use CBCT to determine dosimetric consequences resulting from tumor shrinkage and patient geometry changes. An additional planning CT may be necessary to perform IMRT re-planning at present in order to accurately delineate tumor and organs. The CBCT has potential to become a very useful tool for on-line ART.

Spatial and Dosimetric Variability of Organs at Risk in Head-and-Neck Intensity-Modulated Radiotherapy

PURPOSE

The accuracy of intensity-modulated radiotherapy (IMRT) delivery may be compromised by random spatial error and systematic anatomic changes during the treatment course. We present quantitative measurements of the spatial variability of head-and-neck organs-at-risk and demonstrate the resultant dosimetric effects.

METHODS AND MATERIALS

Fifteen consecutive patients were imaged weekly using computed tomography during the treatment course. Three-dimensional displacements were calculated for the superior and inferior brainstem; C1, C6, and T2 spinal cord; as well as the lateral and medial aspects of the parotid glands. The data were analyzed to show distributions of spatial error and to track temporal changes. The treatment plan was recalculated on all computed tomography sets, and the dosimetric error was quantified in terms of the maximal dose difference (brainstem and spinal cord) or the mean dose difference and the volume receiving 26 Gy (parotid glands).

RESULTS

The mean three-dimensional displacement was 2.9 mm for the superior brainstem, 3.4 mm for the inferior brainstem, 3.5 mm for the C1 spine, 5.6 mm for the C6 spine and 6.0 mm for the T2 spine. The lateral aspects of both parotid glands showed a medial translation of 0.85 mm/wk, and glands shrank by 4.9%/wk. The variability of the maximal dose difference was described by standard deviations ranging from 5.6% (upper cord) to 8.0% (lower cord.) The translation of the left parotid resulted in an increase of the mean dose and the volume receiving 26 Gy.

CONCLUSION

Random spatial and dosimetric variability is predominant for the brainstem and spinal cord and increases at more inferior locations. In contrast, the parotid glands demonstrated a systematic medial translation during the treatment course and thus sparing may be compromised.

Effects of creatine supplementation on nutritional status, muscle function and quality of life in patients with colorectal cancer--a double blind randomised controlled trial

BACKGROUND & AIM

Nutritional status frequently deteriorates during chemotherapy in cancer. This is associated with a poor outcome. Since creatine supplementation has shown promising results in various diseases, we investigated the effects of creatine on nutritional status in patients with colorectal cancer undergoing chemotherapy.

METHODS

Thirty patients with colorectal cancer undergoing chemotherapy were randomised to receive either creatine (n=16) or placebo (n=15) for 8 weeks. Body composition was determined with bioelectrical impedance analysis; muscle function by hand grip, hip flexion and knee extension strength and quality of life (QoL) was assessed by the QLQ30 questionnaire.

RESULTS

Neither muscle function, body cell mass (BCM) nor QoL improved, but phase angle, a marker of BCM and cell integrity, increased significantly in the intervention patients (5.3+/-0.3 degrees to 5.4+/-0.2 degrees , P=0.030). Evaluating patients with different chemotherapy regimens, however, only intervention patients undergoing less aggressive chemotherapy were shown to benefit, increasing phase angle (5.11+/-0.22 degrees to 5.51+/-0.30 degrees , P=0.043) as well as BCM (27.22+/-2.85 to 29.60+/-3.54kg, P=0.043).

CONCLUSION

Creatine failed to improve muscle mass or function and QoL in colorectal cancer patients but improved bioimpedance parameters that are predictive of poor outcome. Creatine might therefore be useful in patients with milder chemotherapy in order to maintain or increase BCM whereas patients undergoing aggressive chemotherapy however are not likely to benefit.

Gastrointestinal toxicity of chemotherapeutic agents

Chemotherapy-induced toxicities commonly occur in sites within the gastrointestinal (GI) tract and account for dose-limiting effects. These toxicities are major contributing factors to dose reduction, delays, and cessation of cancer treatment. Through intensive therapies including surgery, combination chemotherapy, hormonal therapy, and targeted therapy, an increasing number of patients with cancer are experiencing improved survival and long-term disease-free survival, as well as palliation of disease-related symptoms. Thus, GI toxicities should be predicted and appropriate interventions initiated to prevent them when possible and provide effective supportive measures and comprehensive follow-up care. This review will discuss the etiology, incidence, prevention, and treatment of GI toxicities of cancer chemotherapy.

Risk of ventriculoperitoneal shunt infections due to gastrostomy feeding tube insertion in pediatric patients with brain tumors

OBJECTIVE

To determine the risk of ventriculoperitoneal (VP) shunt infections after percutaneous retrograde gastrostomy feeding tube (GT) placement in children with brain tumors.

PATIENTS AND METHODS

All children (age 0-18 years) with primary brain tumors diagnosed and treated at the Hospital for Sick Children, Toronto, Canada, were subjected to a retrospective analysis. Two groups were identified: the study group included children with a VP shunt and a GT; the control group included children with VP shunts only. Each study patient was matched with 2 controls to compare the rate of infections (cohort comparative study).

RESULTS

There were 1,167 children diagnosed and treated with primary brain tumors during the study period (1988-2003); 174 (15%) had a VP shunt and 23 (2%) children had both, a VP shunt and a GT. In the study group (n=17), GTs were inserted at a median time of 80 days (range 6-204 days) after VP shunts. VP shunt infection rate was 23.5% (4/17) compared to 8.8% (3/34) in the control group (OR 3.18; 95% CI 0.622-16.54, p=0.16). Three (75%) of the infection episodes in the study group presented with an ascending VP shunt infection directly related to the GT insertion or manipulation in the first 6 weeks. These GTs were inserted at 13, 47 and 49 days after VP shunt insertion.

CONCLUSION

Placement of percutaneous retrograde GTs, in the acute phase, in children with brain tumors and VP shunts may increase the risk of ascending meningitis especially if there are early GT-related complications.

Repeat CT imaging and replanning during the course of IMRT for head-and-neck cancer

PURPOSE

Many patients with head-and-neck (H&N) cancer have tumor shrinkage and/or weight loss during the course of radiotherapy. We conducted this retrospective study to determine the dosimetric effects of repeat computed tomography (CT) imaging and replanning during the course of intensity-modulated radiotherapy (IMRT) on both normal tissues and target volumes.

METHODS AND MATERIALS

A retrospective chart review identified 13 patients with H&N cancer treated with IMRT who had repeat CT imaging and replanning during the course of radiotherapy. The first IMRT plan for each patient was generated based on the original planning CT scan acquired before the start of treatment. Because of tumor shrinkage or weight loss during radiotherapy, a second CT scan was acquired, and a new plan was generated and used to complete the course of IMRT. CT-CT fusion was used to correct patient positioning differences between the scans. By using a commercial inverse IMRT planning system, a hybrid IMRT plan was generated for each patient by applying the beam configurations of the first IMRT plan (including the intensity profile of each beam) to the anatomy of the second CT scan. The dose-volume histograms of the actual and hybrid IMRT plans were compared using analysis of variance methods for repeated measures.

RESULTS

All patients had locally advanced, nonmetastatic Stage III or IV disease, including 6 nasopharynx, 6 oropharynx, and 1 unknown primary site. All patients were treated with concurrent platinum-based chemotherapy. When replanning vs. not replanning was compared, the hybrid IMRT plans (without replanning) demonstrated reduced doses to target volumes and increased doses to critical structures. The doses to 95% (D95) of the planning target volumes of the gross tumor volume (PTVGTV) and the clinical target volume (PTVCTV) were reduced in 92% of patients, by 0.8-6.3 Gy (p=0.02) and 0.2-7.4 Gy (p=0.003), respectively. The maximum dose (Dmax) to the spinal cord increased in all patients (range, 0.2-15.4 Gy; p=0.003) and the brainstem Dmax increased in 85% of patients without replanning (range, 0.6-8.1 Gy; p=0.007).

CONCLUSIONS

Repeat CT imaging and replanning during the course of IMRT for selected patients with H&N cancer is essential to identify dosimetric changes and to ensure adequate doses to target volumes and safe doses to normal tissues. Future prospective studies with larger sample sizes will help to determine criteria for repeat CT imaging and IMRT replanning for H&N cancer patients undergoing radiotherapy.

Does feeding tube placement predict for long-term swallowing disability after radiotherapy for head and neck cancer?

PURPOSE

To evaluate feeding tube use.

MATERIALS AND METHODS

Nine hundred thirty-four patients were treated with radiotherapy (RT).

RESULTS

Feeding tubes were placed in 235 patients (25%): 212 patients (22.5%) for acute toxicity, 18 patients (2%) for late effects, and 5 patients (0.5%) for both. Median duration of tube dependence for acute toxicity was 3.8 months. Multivariate analysis revealed that feeding tube placement for acute toxicity was increased with higher RT dose (p <.0001), adjuvant chemotherapy (p =.0002), advanced age (p =.0002), and the presence of neck disease (p =.0045). The risk of a feeding tube for late effects was 2% at 5 years. The likelihood of feeding tube placement for late effects was greater for women (p =.0293), higher RT dose (p =.0345), and primary sites, including the hypopharynx and multiple synchronous primary tumors (p =.0360). Feeding tube placement for late effects was unrelated to tube placement for acute toxicity.

CONCLUSION

Likelihood of long-term feeding tube dependence was low and unrelated to placement for acute effects.