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This project developed and validated an automated pipeline for prostate treatments to accurately determine which patients could benefit from adaptive radiotherapy (ART) using synthetic CTs (sCTs) generated from on-treatment cone-beam CT (CBCT) images.
Materials and methods:
The automated pipeline converted CBCTs to sCTs utilising deep-learning, for accurate dose recalculation. Deformable image registration mapped contours from the planning CT to the sCT, with the treatment plan recalculated. A pass/fail assessment used relevant clinical goals. A fail threshold indicated ART was required. All acquired CBCTs (230 sCTs) for 31 patients (6 who had ART) were assessed for pipeline accuracy and clinical viability, comparing clinical outcomes to pipeline outcomes.
Results:
The pipeline distinguished patients requiring ART; 74·4% of sCTs for ART patients were red (failure) results, compared to 6·4% of non-ART sCTs. The receiver operator characteristic area under curve was 0·98, demonstrating high performance. The automated pipeline was statistically significantly (p < 0·05) quicker than the current clinical assessment methods (182·5s and 556·4s, respectively), and deformed contour accuracy was acceptable, with 96·6% of deformed clinical target volumes (CTVs) clinically acceptable.
Conclusion:
The automated pipeline identified patients who required ART with high accuracy while reducing time and resource requirements. This could reduce departmental workload and increase efficiency and personalisation of patient treatments. Further work aims to apply the pipeline to other treatment sites and investigate its potential for taking into account dose accumulation.
This study compares tumor control probability (TCP) and normal tissue complication probability (NTCP) across different hypo-fractionated (HypoRT) and conventional breast radiotherapy regimens using radiobiological models.
Materials and methods:
Computed tomography data from 30 patients with left breast-conserving surgery were used to evaluate three HypoRT regimens (39 Gy and 41·6 Gy in 13 fractions, and 40 Gy in 15 fractions) and a conventional regimen (50 Gy in 25 fractions). Dose-volume histograms (DVHs) were extracted for radiobiological calculations using Equivalent Uniform Dose (EUD) and Poisson models for TCP, and EUD and LKB (Lyman-Kutcher-Burman) models for NTCP.
Results:
Conventional treatment achieved significantly higher TCP (95%) than all HypoRT regimens (p < 0·001), with no significant differences between HypoRT regimens (p > 0·05. The 39 Gy/13 fraction regimen showed the lowest lung NTCP (p < 0·05). HypoRT regimens had significantly lower NTCP for the lungs and heart compared to the conventional regimen (p < 0·01). TCP and NTCP values from Poisson and LKB models were higher than those from the EUD model (p < 0·01).
Conclusion:
HypoRT regimens reduced NTCP, with the lowest values in the regime of 39 Gy/13 fractions regimen, though the conventional regimen had higher TCP.
Radiotherapy is a common treatment modality for cancer patients. Unfortunately, the treatment can result in skin reactions that may affect their quality of life and clinical outcomes. PILs can provide guidance on managing early symptoms and reduce unscheduled treatment breaks. Evaluating PILs is not frequently evidence-based, and research into evaluating PILs’ inclusiveness for radiotherapy skin reactions does not exist. This study aims to contribute to the knowledge base to better serve the whole radiotherapy population.
Methods:
A constructivist methodology was developed to evaluate skin-tone inclusivity in the author’s local PILs, and a literature review was conducted to assess the knowledge base and facilitate providing recommendations for improvement.
Results:
Publication, diagnostic, language and educational bias were identified in the literature. The content analysis found the author’s departmental PILs were not inclusive of medium and dark-skinned patients.
Conclusions:
Further research into radiotherapy PILs inclusivity is warranted. The creation or amendments to existing radiotherapy skin reaction diagnostic tools are needed to cater for the whole population. Diverse educational resources are needed to contribute to the reduction of health inequalities faced by radiotherapy patients.
Temporal bone osteoradionecrosis is a rare but significant complication of radiation for head and neck malignancies. Various management techniques have been described, but no clear protocol exists.
Methods
A retrospective case review of patients with temporal bone osteoradionecrosis managed over 15 years was carried out to highlight multidisciplinary team (MDT) management. The review findings were compared with the published literature and a protocol was derived for the management of future cases.
Results
A total of 20 patients were included. The sites of osteoradionecrosis included the external auditory canal, the middle ear and the lateral skull base, presenting with features including recalcitrant pain, infection, neuropathies and intracranial sepsis. Treatments included hyperbaric oxygen, antibiotics, debridement and, in advanced cases, lateral temporal bone resection with vascularised tissue transfer. Post-operative and long-term outcomes were discussed.
Conclusion
Early temporal bone osteoradionecrosis may be managed conservatively. Refractory osteoradionecrosis can be life-threatening because of intracranial complications and sepsis. Such cases need an MDT approach with radical skull-base surgery for removal of necrotic foci and reconstruction using vascularised tissue transfer.
For over a century, circumferential pharyngoesophageal junction reconstruction posed significant surgical challenges. This review aims to provide a narrative history of pharyngoesophageal junction reconstruction from early surgical innovations to the advent of modern free-flap procedures.
Methods
The review encompasses three segments: (1) local and/or locoregional flaps, (2) visceral transposition flaps, and (3) free-tissue transfer, focusing on the interplay between pharyngoesophageal junction reconstruction and prevalent surgical trends.
Results
Before 1960, Mikulicz-Radecki's flaps and the Wookey technique prevailed for circumferential pharyngoesophageal junction reconstruction. Gastric pull-up and colonic interposition were favoured visceral techniques in the 1960s–1990s. Concurrently, deltopectoral and pectoralis major flaps were the preferred cutaneous methods. Free flaps (radial forearm, anterolateral thigh) revolutionised reconstructions in the late 1980s, yet gastric pull-up and free jejunal transfer remain in selective use.
Conclusions
Numerous pharyngoesophageal junction reconstructive methods have been trialled in the last century. Despite significant advancements in free-flap reconstruction, some older methods are still in use for challenging clinical situations.
In decision making regarding the management of vestibular schwannomas, alongside clinical outcomes, an understanding of patient reported health-related quality of life measures is key. Therefore, the aim of this research is to compare health-related quality of life in vestibular schwannoma patients treated with active observation, stereotactic radiotherapy and microsurgical excision.
Methods
A cross-sectional study of patients diagnosed with unilateral sporadic vestibular schwannomas between 1995 and 2015 at a specialist tertiary centre was conducted. Patients completed the Penn Acoustic Neuroma Quality of Life questionnaire and handicap inventories for dizziness, hearing and tinnitus.
Results
Of 234 patients, 136 responded (58.1 per cent). Management modality was: 86 observation, 23 stereotactic radiotherapy and 25 microsurgery. Females reported significantly worse dizziness; males reported significantly worse physical disability. Patients less than 65 years old reported significantly worse tinnitus and pain scores. Overall, quality of life was higher in the observation group.
Conclusion
Conservative management, where appropriate, is favourable with higher quality-of-life outcomes in this cohort. This must be weighed against the risks of a growing tumour.
Neoadjuvant radiotherapy (RT) is commonly used as standard treatment for rectal cancer. However, response rates are variable and survival outcomes remain poor, highlighting the need to develop new therapeutic strategies. Research is focused on identifying novel methods for sensitising rectal tumours to RT to enhance responses and improve patient outcomes. This can be achieved through harnessing tumour promoting effects of radiation or preventing development of radio-resistance in cancer cells. Many of the approaches being investigated involve targeting the recently published new dimensions of cancer hallmarks. This review article will discuss key radiation and targeted therapy combination strategies being investigated in the rectal cancer setting, with a focus on exploitation of mechanisms which target the hallmarks of cancer.
The main goal of radiation therapy is to eradicate all cancer cells and minimize the damage to healthy tissues around the tumour. Treatment planning systems are used to predict the outcome of the treatment in terms of dose distribution prior to the treatment. One of the most reliable dose calculation algorithms is Monte Carlo. The aim of this study is to evaluate the performance of automated external contouring tool on dose calculation using Monte Carlo algorithm.
Materials and methods
The external contour of thorax phantom was created by automated tools of Monaco treatment planning system, and then, the IAEA-TECDOC-1583 quality assurance tests were created. Then, the treatment plans were delivered to the phantom, and the dose was measured by the Farmer ionization chamber at specific points. The external contour was corrected according to the source surface distances (SSD) which are mentioned in TECDOC-1583, and the dose was re-calculated. Finally, a comparison was made between the results.
Results
Dosimetric tests of TECDOC-1583 showed the errors ranged from −2·8% to +2·5%. In case of editing external contour and omitting fluctuations, the errors were decreased. The comparisons indicated that the most significant variation occurred in test 4 and the least changes were related to the tests 1 and 3.
Conclusions
The results of the study showed that the fluctuations of the external contour affect the calculated volume of the phantom and thus the dose. In order to obtain correct results, automated external contouring tools should be used with the correct instructions and re-checked before treatment planning.
To determine oncological and functional outcomes in patients with T3 and T4 laryngeal carcinoma, in which choice of treatment was based on expected laryngeal function and not T classification.
Methods
Oncological outcomes (disease-specific survival and overall survival) as well as functional outcomes (larynx preservation and functional larynx preservation) were analysed.
Results
In 130 T3 and 59 T4 patients, there was no difference in disease-specific survival or overall survival rates after radiotherapy (RT) (107 patients), chemoradiotherapy (36 patients) and total laryngectomy (46 patients). The five-year disease-specific survival rates were 83 per cent after RT, 78 per cent after chemoradiotherapy and 69 per cent after total laryngectomy, whereas overall survival rates were 62, 54 and 60 per cent, respectively. Five-year larynx preservation and functional larynx preservation rates were comparable for RT (79 and 66 per cent, respectively) and chemoradiotherapy (86 and 62 per cent, respectively).
Conclusion
There is no difference in oncological outcome after (chemo)radiotherapy or total laryngectomy in T3 and T4 laryngeal carcinoma patients whose choice of treatment was based on expected laryngeal function.
A pathological communication between the trachea and oesophagus – a tracheoesophageal fistula – may be congenital or acquired, benign or malignant, necessitating a multidisciplinary approach. Conservative attempts at closure of this abnormal connection are ineffective; the interposition of healthy vascular tissue offers the least chance of recurrence.
Methods
Outcomes of an islanded fasciocutaneous internal mammary artery perforator flap applied for tracheoesophageal fistula management were assessed in four radiated patients with laryngeal carcinoma using retrospective records.
Results
Four male patients, with an average age of 60.75 years, underwent tracheoesophageal fistula closure between September 2017 and February 2021. A left-sided second internal mammary artery perforator flap was used in all cases, with an average dimension of 10.5 × 4.5 cm. There were no complications of tracheoesophageal leak, flap issues or donor site morbidity on follow up.
Conclusion
Recent advances in angiosomal territory mapping and microvascular dissection techniques, combined with an understanding of tracheoesophageal fistula pathology, have changed management perspectives in these difficult-to-treat patients.
Radiotherapy for pediatric brain tumor has been associated with late cognitive effects. Compared to conventional photon radiotherapy (XRT), proton radiotherapy (PRT) delivers less radiation to healthy brain tissue. PRT has been associated with improved long term cognitive outcomes compared to XRT. However, there is limited research comparing the effects of XRT and PRT on verbal memory outcomes.
Participants and Methods:
Survivors of pediatric brain tumor treated with either XRT (n = 29) or PRT (n = 51) completed neuropsychological testing > 1 year following radiotherapy. XRT and PRT groups were similar with respect to sex, handedness, race, age at diagnosis, age at evaluation, tumor characteristics, and treatment history (i.e., craniospinal irradiation, craniotomy, shunting, chemotherapy, radiation dose). Verbal learning and memory were assessed using the age-appropriate version of the California Verbal Learning Test (CVLT-II/CVLT-C). Measures of intellectual functioning, executive functioning, attention and adaptive behavior were also collected. Performance on neuropsychological measures was compared between treatment groups (XRT vs. PRT) using analysis of covariance (ANCOVA). On the CVLT, each participant was classified as having an encoding deficit profile (i.e., impaired learning, recall, and recognition), retrieval deficit profile (i.e., impaired recall but intact recognition), intact profile, or other profile. Chi-squared tests of independence were used to compare the probability of each memory profile between treatment groups. Pearson correlation was used to examine associations between memory performance and strategy use, intellectual functioning, adaptive behavior, attention, and executive functioning.
Results:
Overall, patients receiving PRT demonstrated superior verbal learning (CVLT Trials 1-5; t(76) = 2.61, p = .011), recall (CVLT Long Delay Free; t(76) = 3.57, p = .001) and strategy use (CVLT Semantic Clustering; t(76) = 2.29, p = .025) compared to those treated with XRT. Intact performance was more likely in the PRT group than the XRT group (71% PRT, 38% XRT; X2 = 8.14, p = .004). Encoding and retrieval deficits were both more common in the XRT group, with encoding problems being most prevalent (Encoding Deficits: 31% XRT, 12% PRT, X2 = 4.51, p = .034; Retrieval Deficits: 17% XRT, 4% PRT, X2 = 4.11, p = .043). Across all participants, semantic clustering predicted better encoding (r = .28, p = .011) and retrieval (r = .26, p = .022). Better encoding predicted higher intellectual (r = .56, p < .001) and adaptive functioning (r = .30, p = .011), and fewer parent-reported concerns about day-today attention (r = -.36, p = .002), and cognitive regulation (r = -.35, p = .002).
Conclusions:
Results suggest that PRT is associated with superior verbal memory outcomes compared to XRT, which may be driven by encoding skills and use of learning strategies. Moreover, encoding ability predicted general intellectual ability and day-to-day functioning. Future work may help to clarify underlying neural mechanisms associated with verbal memory decline following radiotherapy, which will better inform treatment approaches for survivors of pediatric brain tumor.
Radiotherapy for pediatric brain tumor is associated with reduced white matter structural integrity and neurocognitive decline. Superior cognitive outcomes have been reported following proton radiotherapy (PRT) compared to conventional photon radiotherapy (XRT), presumably due to sparing of healthy brain tissue. This study examined long-term white matter change and neuropsychological performance in pediatric brain tumor survivors treated with XRT vs. PRT.
Participants and Methods:
Pediatric brain tumor survivors treated with either XRT (n = 10) or PRT (n = 12) underwent neuropsychological testing and diffusion weighted imaging > 7 years following radiotherapy. A healthy control group (n = 23) was also recruited. Groups had similar demographic characteristics, except for handedness (p = .01), mean years of age at testing (XRT = 21.7, PRT = 16.9, Control = 15.5; p = .01), and mean years since radiation (XRT =14.7, PRT = 8.9, p < .001). Age and handedness were selected as covariates; analyses were not adjusted for time since radiation due to redundancy with treatment group (i.e., standard of care transitioned from XRT to PRT in 2007). Participants completed age-appropriate versions of the Weschler Intelligence Scales (WAISIV/WISC-IV/WISC-V) and the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI and Motor Coordination subtests). Tractography was conducted using automated fiber quantification (AFQ), and fractional anisotropy (FA) was extracted from 12 tracts of interest. Linear mixed models were used to summarize group differences in FA, with tracts nested within subjects. Neuropsychological performance and tract-level FA were compared between groups using analysis of covariance (ANCOVA). Pearson correlation was used to examine associations between cognitive functioning and tract-level FA.
Results:
Across all tracts, FA was significantly lower in the XRT group than the PRT group (t(514) = -2.58, p = .01), but did not differ between PRT and Control groups (t(514) = .65, p = .51). For individual tracts, FA differed significantly between treatment groups (XRT < PRT) in the left inferior fronto-occipital fasciculus (IFOF), right IFOF, left inferior longitudinal fasciculus (ILF) and right uncinate (all t < -2.05, all p < .05). No significant differences in FA were found between PRT and Control participants for any tract. All neuropsychological scores were significantly lower for XRT than PRT patients (all p < .03), while PRT and Control groups performed similarly on these measures (all p >.19). Cognitive functioning was most consistently associated with FA of the corpus callosum major forceps (4/7 domains; all r > .33, all p < .04) and the left ILF (4/7 domains; all r > .37, all p <.02).
Conclusions:
Both white matter integrity and neuropsychological performance were generally reduced in patients with a history of XRT, but not in those who received PRT. The PRT group was similar to healthy control participants with respect to both FA and cognitive scores, suggesting improved long-term outcomes compared to patients receiving XRT. This exploratory study is the first to provide direct support for white matter integrity as a mechanism of cognitive sparing in PRT. Future work with larger samples is necessary to replicate these findings.
Treatment for pediatric brain tumors (PBTs) is associated with neurocognitive risk, including declines in IQ, executive function, and visual motor processing. Low grade tumors require less intensive treatment (i.e., focal radiotherapy (RT) or surgical resection alone), and have been associated with more favorable cognitive outcomes. However, these patients remain at risk of cognitive problems, which may present differently depending on tumor location. Executive functioning (EF), in particular, has been broadly associated with both frontal-subcortical networks (supratentorial) and the cerebellum (infratentorial). The current study examined intellectual functioning, executive functioning (set-shifting and inhibition), and visual motor skills in patients who were treated for low-grade tumors located in either the supratentorial or infratentorial region.
Participants and Methods:
Participants were survivors (age 8-18) previously treated with focal proton RT or surgery alone for infratentorial (n=21) or supratentorial (n=34) low grade glioma (83.6%) or low grade glioneuronal tumors (16.4%). Survivors >2.5 years post-treatment completed cognitive testing (WISC-IV/WAIS-IV; D-KEFS Verbal Fluency (VF), Color-Word Interference (CW), Trail Making Test (TM); Beery Visual-Motor Integration). We compared outcomes between infratentorial and supratentorial groups using analysis of covariance (ANCOVA). Demographic and clinical variables were compared using Welch’s t-tests. ANCOVAs were adjusted for age at evaluation, age at treatment, and history of posterior fossa syndrome due to significant or marginally significant differences between groups.
Results:
Tumor groups did not significantly differ with respect to sex (49.0% male), length of follow-up (M 4.4 years), or treatment type (74.5% surgery alone, 25.5% proton RT). Marginally significant group differences were found for age at evaluation (infratentorial M = 12.4y, supratentorial M = 14.1y, p = .054) and age at treatment (infratentorial M = 7.9y, supratentorial M = 9.7y, p =.074). Posterior fossa syndrome only occurred with infratentorial tumors (n=5, p = .003). Adjusting for covariates, the supratentorial group exhibited significantly superior performance on a measure of inhibition and set-shifting (CW Switching Time (t(32) = -2.05, p=.048, n2 =.11). There was a marginal group difference in the same direction on CW Inhibition Time (t(32 = -1.77, p = .086, n2 =.08). On the other hand, the supratentorial group showed significantly lower working memory than the infratentorial group (t(50) = 2.45, p = .018, n2 = .11), and trends toward lower verbal reasoning (t(50)=1.96, p = .056, n2 = .07) and full-scale IQ (t(50)=1.73, p = .090, n2 = .055). No other group differences were identified across intellectual, EF, and visualmotor measures.
Conclusions:
Infratentorial tumor location was associated with weaker switching and inhibition performance, while supratentorial tumor location was associated with lower performance on intellectual measures, particularly working memory. These findings suggest that even with relatively conservative treatment (i.e., focal proton RT or surgery alone), there remains neurocognitive risk in children treated for low-grade brain tumors. Moreover, tumor location may predict distinct patterns of long-term neurocognitive outcomes, depending on which brain networks are involved.
This study aimed to investigate the patient’s perception of the usefulness and limitations of a mobile application as part of the supportive care provided to patients undergoing radiotherapy.
Methods:
Patients undergoing radiotherapy between February 2023 and March 2023 at a local oncology hospital (n = 150) were invited to complete a questionnaire that assessed the patient’s smartphone knowledge, willingness to use an app during radiotherapy, perceptions of the usefulness of specific app features, and barriers to using such applications. For quantitative analysis, frequencies were obtained for all areas of interest, and the results were correlated with the patient’s demographics.
Results:
Of the 39 participants who completed the questionnaire, 82·1% had a smartphone device, 59% could use their smartphones with minimal to no help and 41% had not used their smartphones for medical purposes before. However, 79·5% of patients showed a strong interest in using a mobile app during radiotherapy. Age, gender and level of education had no significant impact on the acceptability of using the mobile application for radiotherapy purposes.
Conclusion:
Overall, the findings indicate that most patients have access to mobile technology and are willing to use the mobile app as an additional supportive care tool.
It is already well-understood that patients requiring multiple hospital visits deal with several barriers. This paper considers a new methodology for determining the barrier that travel can cause, applying it to the mixed rural-city population of South-West Wales, calculating the travel burden for patients accessing radiotherapy. Travel burden could factor into conversations around optimisation of appointments and the impact of changes to treatment pathways.
Methods:
Patient-specific travel data were calculated using Google Maps, for 1516 patients attending South-West Wales Cancer Centre for radiotherapy, modelled for 5-fraction and 15-fraction regimes.
Results:
28% of patients travelled for longer than 60 minutes. Moving to a 5-fraction treatment regime saves 20 one-way trips to the hospital, resulting in an average time saving of 15.9 hours for those travelling by car and 39.3 hours for those travelling by public transport. On average, this reduces carbon dioxide emissions by 91 kg per patient.
Conclusions:
Implementation of a 5-fraction treatment regime has significantly reduced the travel burden for some patients receiving radiotherapy, as well as emissions related to travel. However, access to radiotherapy services in South-West Wales varies, with certain regions facing substantial travel burdens. Further research exploring other potential options to reduce travel burden is needed.
Advanced treatment modalities involve applying small fields which might be shaped by collimators or circular cones. In these techniques, high-energy photons produce unwanted neutrons. Therefore, it is necessary to know neutron parameters in these techniques.
Materials and methods:
Different parts of Varian linac were simulated by MCNPX, and different neutron parameters were calculated. The results were then compared to photoneutron production in the same nominal fields created by circular cones.
Results:
Maximum neutron fluence for 1 × 1, 2 × 2, 3 × 3 cm2 field sizes was 165, 40.4, 19.78 (cm–2.Gy-1 × 106), respectively. The maximum values of neutron equivalent doses were 17.1, 4.65, 2.44 (mSv/Gy of photon dose) for 1 × 1, 2 × 2, 3 × 3 cm2 field size, respectively, and maximum neutron absorbed doses reached 903, 253, 131 (µGy/Gy photon dose) for 1 × 1, 2 × 2, 3 × 3 cm2 field sizes, respectively.
Conclusion:
Comparing the results with those in the presence of circular cones showed that circular cones reduce photoneutron production for the same nominal field sizes.
Cancer during pregnancy is rare, affecting approximately 1 in 1 000 pregnancies. Although rare, most obstetricians will at times be responsible for women who have a history of cancer, or present with symptoms or signs of possible malignancy during pregnancy, or even encounter a new diagnosis during a current pregnancy. Pregnancy itself does not predispose to cancer, but there may be delays in diagnosis due to symptoms being falsely attributed to physiological symptoms related to pregnancy.
Secondary oesophageal carcinoma from a breast primary is an infrequent phenomenon. Given the rarity of this presentation, there is a general lack of consensus on management guidelines.
Materials and methods:
Herein, we report a case of a 65-year-old female presented with dysphagia, 14 years post-surgery for breast cancer. She was diagnosed with oesophageal metastases and was treated with combination of systemic chemotherapy, hormonal therapy and local radiotherapy. Our patient tolerated the treatment well and achieved a significant symptomatic improvement post-radiotherapy. We also performed a review of literature on oesophageal metastases from breast primary, aiming to improve the diagnostic accuracy and treatment efficacy in this rare presentation.
Conclusions:
We conclude that patients who present with persistent dysphagia post-breast cancer treatment should undergo an endoscopic ultrasound (EUS)-guided fine-needle biopsy (FNB) to rule out oesophageal metastasis. We suggest systemic chemotherapy with hormonal therapy and radiotherapy for local control as a management of choice in this condition. Even though prognosis is difficult to predict in these patients, this combined modality of treatment seems to achieve better overall survival.
This work aims to evaluate the effect of Hitachi 16-slice scanner reconstruction filters on Hounsfield unit (HU) variations. In the literature, there is a lack of information from a wide variety of scanners in this regard. In addition, not all studies have investigated the effect of reconstruction filters on HU in an exhaustive way.
Methods:
The computerised imaging reference system electron density phantom (model 062M) was scanned with different substitute materials of different density from Hitachi 16-slice computed tomography. The raw images were obtained with four tube voltage settings: 80 kVp, 100 kVp, 120 kVp and 140 kVp. The raw images for each energy level were then reconstructed using different reconstruction filters.
Results:
The HU values of dense bone were significantly different when changing the reconstruction filters without beam hardening correction (BHC). Nevertheless, when selecting the BHC, this variation decreases heavily for 80 kVp and decreases slightly for 140 kVp, but it remains outside the tolerance of ±50 HU. However, for 100 kVp and 120 kVp, the differences in HU values become within the tolerances indicated for dense bone.
Conclusions:
Changing image reconstruction filters during a dosimetric scan had a significant effect on HU in dense bone. Therefore, it is recommended to evaluate this effect during the commissioning phase. As a result, this study provides a methodology to comprehensively investigate the effect of reconstruction filters on HU.