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- Ottosson, Sandra, 1981-
(författare)
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Impact of disease and treatment on body weight and eating in patients with head and neck cancer : experiences from a multicenter study
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background Nutritional deterioration in patients with head and neck cancer (HNC) has a multifactorial etiology mainly associated with tumor and treatment related factors. The objective of the present thesis was to investigate the impact of the disease and treatment on body weight and eating in patients with HNC treated with radiation therapy (RT) as the single modality treatment or as preoperative RT by analyzing body weight and body mass index (BMI) over time, predictive factors for weight loss and BMI, weight loss and BMI as prognostic factors for survival, and by studying the patients’ own experience of food and eating.Methods ARTSCAN is a randomized prospective multicenter trial conducted between the years of 1998 - 2006. Data were collected during and after RT with a total follow-up time of five years. Nutritional data from the whole study cohort (n = 712), from patients with oropharyngeal cancer (n = 232) and from two of the participating treatment centers (n = 101) were retrospectively analyzed in the present thesis. In addition, interviews (n = 13) were conducted nine months after the termination of RT as part of a care development project.Results On a group level, the patients lost weight during and after RT with a nadir at five months after the termination of RT. Factors related to a higher weight loss were oropharyngeal cancer, a high BMI at the start of RT, post-treatment aspiration, no tube feeding at the start of RT, and larger treated volumes. Furthermore, a high BMI at the start of RT was shown to be significantly related to a better five-year overall survival in patients with oropharyngeal cancer, whereas weight loss was not. The patients’ own narratives showed that all aspects of food, eating and meals were affected by the remaining sequelae, and that the patients found ways to accept and cope with the changes that had to be done to facilitate eating.Conclusions and clinical implications The disease and treatment gave persistent effects on the HNC patients’ weight and BMI which calls for a prolonged nutritional follow-up. The predictive factors found for weight loss can be used during patient history to find patients at risk for nutritional deterioration. In oropharyngeal cancer, patients with a high BMI at the start of RT had the best survival. This finding indicates that patients with a low BMI should be encouraged to gain weight before RT start. All aspects of food, eating and meals were affected during and after RT, and therefore the nutritional treatment should be given with a holistic approach to meet the multifaceted need patients with HNC experience.
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| 2. |
- Söderström, Karin, 1977-
(författare)
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Radiotherapy for head and neck cancer : costs and benefits of time, dose and volume
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background In the treatment of head and neck cancers (HNCs), radiotherapy (RT) has the advantage of organ preservation compared to surgery. However, treatment toxicities associated with RT can affect important functions for everyday life, both in the acute and late stage. RT to macroscopic tumour in HNC is commonly combined with elective RT to cervical lymph nodes at risk of microscopic involvement. The resulting risk reduction of the elective treatment based on dose-volume parameters is sparsely evaluated. So is the relationship between the elective treatment and treatment toxicity. The present thesis addresses these aspects.A strategy aimed at improving the outcome of RT is accelerated fractionation (AF). AF strives to shorten total treatment time to minimise proliferation of the tumour tissue during the RT period. We have investigated the impact of AF on both disease control and toxicity.Methods In the ARTSCAN study, 750 patients with localised HNC were randomised between AF (68 Gy in 4.5 weeks) and conventional fractionation (CF) (68 Gy in 7 weeks). The elective treatment volume was prescribed 46 Gy with CF in both treatment arms. The thesis is based on four individual papers, investigating the issues above in the whole study population or in sub-populations.Results No difference in disease control or late toxicity between CF and AF was observed at five years. However, there was an increased acute toxicity with AF. Weight loss was associated with treatment volume, independent of tumour stage. The elective treatment volume was found to be an independent risk factor for late aspiration, as well as mean dose to the pharyngeal constrictor muscles, neck dissection, and age at randomisation. There was a significant risk reduction for node relapses in volumes treated to an elective dose. Only a relapse in volumes treated to >60 Gy affected the survival.Conclusion The present thesis questions the benefit of AF in definitive RT as well as extensive elective treatment of the cervical nodes.
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| 3. |
- Olausson, Kristina, 1972-
(författare)
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Patient experiences of the radiotherapy process and treatment
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundMost cancer patients undergo external radiotherapy (RT) at some stage during their treatment trajectory. RT is often associated with unfamiliar procedures where the technical environment, side effects and interaction with staff seem to play a major role in the patient’s treatment experience. These experiences could sometimes lead to disruption of the treatment which may have negative consequences for the outcome. The overall aim of this thesis was to gain further knowledge about how patients experience RT and the related processes. Such knowledge is of vital importance when developing and improving care within a high-tech RT environment.AimThe overall aim of this thesis was to gain further knowledge about how patients experience RT and the related processes. Such knowledge is of vital importance when developing and improving care within a high-tech RT environment.MethodsTo gain further knowledge and understanding about patients experience of RT both quantitative (I, II, III) and qualitative (III, IV) methodology were used. The data in the thesis focused on patients undergoing external RT at different RT units in Sweden. Study I and II, focused on two regions, the northern region of Sweden and the region of Stockholm and Gotland. Study III and IV were performed at eight different RT units in Sweden.ResultsIn Study I, two types of topical agents (Calendula Weleda cream vs. Essex cream) were compared regarding reducing the risk of severe acute radiation skin reactions (ARSR). No difference in severe ARSR was found between the groups and the patients reported low levels of ARSR. In Study II, the influence of an RT unit’s psychosocial climate and treatment environment on cancer patients’ anxiety during external RT was evaluated. Data was collected (questionnaire) from 892 patients. The results showed that both the treatment environment and the psychosocial climate of the RT unit significantly impacted cancer patient anxiety levels. In Study III & IV, a questionnaire to measure the patient´s experience during external RT was developed and tested. The results showed that the RT Experience Questionnaire (RTEQ), with 23 items, was a tentatively valid and reliable instrument to measure how patients experience the RT process and the environment in the treatment room. In Study IV, written comments from the open-ended question “Is there anything else you want us to know?” in the preliminary RTEQ was analysed with qualitative content analysis. This data was abstracted into the following four major categories reflecting the experience of the RT process: Experiences in the high tech RT environment; Understanding the RT procedures and side effects; Dealing with daily life during RT and The nurses’ role and performance.ConclusionThe RT environment and the RT related processes seem to impact cancer patients, both physically and psychologically. A person-centered care approach, as well as attention to the design, both of the treatment process and the physical environment could significantly improve the patient experience and patient involvement. The results also highlight the importance of taking patient experiences into account when introducing new RT methods and techniques.
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- Rojas Callejas, Ana Maria, 1948-
(författare)
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ARCON in experimental and clinical radiotherapy
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- xHypoxia and repopulation of tumour clonogens are two important determinants of treatment outcome in radiotherapy. In general clinical evidence indicates that loco-regional control may be reduced with long overall treatment times and for tumours with low pre-treatment levels of oxygen. Experimental studies with normobaric carbogen and oxygen showed a two-fold enhancement of the efficacy of radiation in a mouse tumour model when combining oxygen with treatment acceleration. It was then demonstrated that substituting carbogen for oxygen and adding high-dose nicotinamide (NAM) further increased the effect. These findings became the basis for a multi-factorial approach designed to overcome the radioprotective effect of tumour repopulation and that of perfusion–limited and diffusion–limited hypoxia. The strategy, named ARCON, combines Accelerated Radiotherapy with CarbOgen and Nicotinamide. Experimental evaluation of ARCON The therapeutic potential of carbogen combined with NAM (CON) focusing on treatment schedules that use clinically relevant radiation and drug dose levels was evaluated in tumour and normal tissue animal models. Some of the conditions under which ARCON gives the largest degree of tumour radiosensitization and therapeutic benefit were identified. Specifically, NAM-dose level, pharmacokinetics and scheduling, and the effect of NAM on repair processes in vivo were also investigated. The results showed that in conventional and accelerated radiotherapy, carbogen and CON are effective and relatively non-toxic tumour sensitizers. They also demonstrated that tumour sensitization with CON was independent of time of NAM administration but that it was drug dose dependent. Some degree of normal tissue sensitization was observed but even relative to mouse skin a significant therapeutic gain was achieved. The mechanism of action for NAM sensitization originally proposed was that of repair inhibition. In the in vivo mouse models tested, namely skin and kidney, NAM did not alter the rate nor the magnitude of repair of radiation induced damage. Clinical evaluation of ARCON In the early 90s, various centres, particularly in the UK, Sweden, Holland and Switzerland, undertook clinical trials of ARCON. The protocols were designed based on detailed considerations of the rodent and human radiation and pharmacokinetic studies. This document also discusses the findings of a phase II non-randomized trial in advanced bladder cancer of accelerated radiotherapy combined with carbogen alone and ARCON. The aim of the study was to establish the feasibility of administering carbogen and NAM to patients and to determine the extent of early and late normal tissue damage. Historical comparisons suggested no overt increase in normal tissue radiosensitivity and the data indicate that ARCON could achieve a therapeutic gain in advanced bladder cancer.
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| 5. |
- Zarei, Maryam, et al.
(författare)
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Accuracy of gross tumour volume delineation with [68Ga]-PSMA-PET compared to histopathology for high-risk prostate cancer
- 2024
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Ingår i: Acta Oncologica. - : MJS Publishing, Medical Journals Sweden. - 0284-186X .- 1651-226X. ; 63, s. 503-510
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The delineation of intraprostatic lesions is vital for correct delivery of focal radiotherapy boost in patients with prostate cancer (PC). Errors in the delineation could translate into reduced tumour control and potentially increase the side effects. The purpose of this study is to compare PET-based delineation methods with histopathology.MATERIALS AND METHODS: The study population consisted of 15 patients with confirmed high-risk PC intended for prostatectomy. [68Ga]-PSMA-PET/MR was performed prior to surgery. Prostate lesions identified in histopathology were transferred to the in vivo [68Ga]-PSMA-PET/MR coordinate system. Four radiation oncologists manually delineated intraprostatic lesions based on PET data. Various semi-automatic segmentation methods were employed, including absolute and relative thresholds, adaptive threshold, and multi-level Otsu threshold.RESULTS: The gross tumour volumes (GTVs) delineated by the oncologists showed a moderate level of interobserver agreement with Dice similarity coefficient (DSC) of 0.68. In comparison with histopathology, manual delineations exhibited the highest median DSC and the lowest false discovery rate (FDR) among all approaches. Among semi-automatic approaches, GTVs generated using standardized uptake value (SUV) thresholds above 4 (SUV > 4) demonstrated the highest median DSC (0.41), with 0.51 median lesion coverage ratio, FDR of 0.66 and the 95th percentile of the Hausdorff distance (HD95%) of 8.22 mm.INTERPRETATION: Manual delineations showed a moderate level of interobserver agreement. Compared to histopathology, manual delineations and SUV > 4 exhibited the highest DSC and the lowest HD95% values. The methods that resulted in a high lesion coverage were associated with a large overestimation of the size of the lesions.
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