BACKGROUND: Thanks to their distinct physical properties proton therapy (PT) offers a superior dose distribution than photon radiation therapy. For brain and skull base (SB) tumors such dose sparing ...can be harnessed: a) in benign tumors, to achieve long-term better quality of life and reduced risk of neurocognitive deficits as well as radiation-related malignancies by delivering standard dose level; b) in malignant tumors or malignancies with local aggressiveness, to improve local control by safe delivery of tumor dose escalation. In the following we report an overview on our facility and the neuro-oncology program. METHODS/RESULTS: The Trento facility is built on over an area that will host the new Trento Hospital so that it will be a hospital-based PT center. As opposed to most centers using PT in the past, our facility is equipped with active beam delivery employing the spot scanning technique. A cyclotron provides a library of pencil beams of variable energy (70 - 226 MeV) and spot size ( sigma , 3 - 7 mm). Within the center, radiation therapy is offered in two treatment rooms. To allow for 360 degree rotation of the beamline these rooms are equipped with two gantries. In the treatment rooms, patients are placed on a robotic treatment table offering maximal variability and flexibility for patient positioning. The rooms are also equipped with devices enabling X-ray for treatment position verification. In a second step, the rooms will be equipped with cone-beam CT (room 1) and CT on-rails (room 2). Additionally there is one room equipped with horizontal beamline and equivalent beam scanning technology dedicated to quality assurance and preclinical research. For treatment planning imaging, the center is equipped with a dedicated CT and 1.5T MR. The staff is composed by professionals that experienced in leading particle centers in Villigen (CH), Heidelberg (GER), Boston (USA), Jacksonville (USA), Philadelphia (USA). Dedicated protocols for tumors of the brain and SB, for both adults and pediatric patients will be conducted based on the previous conducted trials on PT and potential expected benefit. As mentioned above, according to different clinical aims we are going to treat both benign and malignant tumors. The former group includes pituitary adenomas, schwannoma, benign meningioma, chondrosarcoma, craniopharyngioma, ependymoma, low-grade gliomas, medulloblastoma. In a second step, a PT radiosurgery program will be implemented for some of them. The latter group includes chordoma, high-grade gliomas, and atypical-malignant meningiomas. Regardless of the tumor type patients can be accepted also for re-irradiation. CONCLUSIONS: After a dedicated planning, construction and commissioning phase, patient treatment at Trento PT center is expected for summer 2014. Based on the already demonstrated as well as further potential clinical benefit neuro-oncology represents one of the most important field of interest.
In breast cancer (BC) patients, conservative surgery (CS) followed by irradiation or immediate breast reconstruction (IBR) after modified radical mastectomy (MRM) has been proposed in the attempt to ...avoid the negative impact of MRM on feminine body image. Regardless of the type of operation, BC patients may feel pain even without recurrent disease with poor adjustment in terms of quality of life (QL).
We adopted a questionnaire comprising the short form of the McGill Pain questionnaire, and a previously validated questionnaire able to identify four subscales exploring physical well-being, physical autonomy, relational life and psychological well-being. The questionnaire was mailed in 1999 to a consecutive series of 757 (CS: 481 cases; MRM + IBR with skin expander: 93 cases; MRM: 183 cases) disease-free patients treated for BC between March 1995 and March 1998.
The final analysis assessed the data relating to 529 patients who underwent axillary dissection. Pain was reported by 39.7% of women with higher incidence in patients who underwent CS than in those who underwent MRM +/- IBR, but this difference did not reach statistical significance (p = 0.07). The only statistically significant difference (p < 0.05) between the surgical groups was the pain appearance that occurred earlier in the CS patients and later in the MRM + IBR patients. No other differences were observed. The women with pain had significantly worse QL scores on all of the subscales than those without.
Pain after surgery for BC distress almost one-third of patients, regardless of the type of treatment, and had a negative effect on patients' QL. The different surgical procedures may marginally influence the quantitative characteristics of pain.
Purpose
Intensity-modulated radiation therapy (IMRT) is the state-of-the-art treatment for patients with malignant pleural mesothelioma (MPM). The goal of this work was to assess whether ...intensity-modulated proton therapy (IMPT) could further improve the dosimetric results allowed by IMRT.
Patients and methods
We re-planned 7 MPM cases using both photons and protons, by carrying out IMRT and IMPT plans. For both techniques, conventional dose comparisons and normal tissue complication probability (NTCP) analysis were performed. In 3 cases, additional IMPT plans were generated with different beam dimensions.
Results
IMPT allowed a slight improvement in target coverage and clear advantages in dose conformity (p < 0.001) and dose homogeneity (p = 0.01). Better organ at risk (OAR) sparing was obtained with IMPT, in particular for the liver (D
mean
reduction of 9.5 Gy, p = 0.001) and ipsilateral kidney (V
20
reduction of 58%, p = 0.001), together with a very large reduction of mean dose for the contralateral lung (0.2 Gy vs 6.1 Gy, p = 0.0001). NTCP values for the liver showed a systematic superiority of IMPT with respect to IMRT for both the esophagus (average NTCP 14% vs. 30.5%) and the ipsilateral kidney (p = 0.001). Concerning plans obtained with different spot dimensions, a slight loss of target coverage was observed along with sigma increase, while maintaining OAR irradiation always under planning constraints.
Conclusion
Results suggest that IMPT allows better OAR sparing with respect to IMRT, mainly for the liver, ipsilateral kidney, and contralateral lung. The use of a spot dimension larger than 3 × 3 mm (up to 9 × 9 mm) does not compromise dosimetric results and allows a shorter delivery time.
Delineation of clinical target volume (CTV) is still controversial in glioblastomas. In order to assess the differences in volume and shape of the radiotherapy target, the use of pre-operative vs ...post-operative/pre-radiotherapy T(1) and T(2) weighted MRI was compared.
4 CTVs were delineated in 24 patients pre-operatively and post-operatively using T(1) contrast-enhanced (T1(PRE)CTV and T1(POST)CTV) and T(2) weighted images (T2(PRE)CTV and T2(POST)CTV). Pre-operative MRI examinations were performed the day before surgery, whereas post-operative examinations were acquired 1 month after surgery and before chemoradiation. A concordance index (CI) was defined as the ratio between the overlapping and composite volumes.
The volumes of T1(PRE)CTV and T1(POST)CTV were not statistically different (248 ± 88 vs 254 ± 101), although volume differences >100 cm(3) were observed in 6 out of 24 patients. A marked increase due to tumour progression was shown in three patients. Three patients showed a decrease because of a reduced mass effect. A significant reduction occurred between pre-operative and post-operative T(2) volumes (139 ± 68 vs 78 ± 59). Lack of concordance was observed between T1(PRE)CTV and T1(POST)CTV (CI = 0.67 ± 0.09), T2(PRE)CTV and T2(POST)CTV (CI = 0.39 ± 0.20) and comparing the portion of the T1(PRE)CTV and T1(POST)CTV not covered by that defined on T2(PRE)CTV images (CI = 0.45 ± 0.16 and 0.44 ± 0.17, respectively).
Using T(2) MRI, huge variations can be observed in peritumoural oedema, which are probably due to steroid treatment. Using T(1) MRI, brain shifts after surgery and possible progressive enhancing lesions produce substantial differences in CTVs. Our data support the use of post-operative/pre-radiotherapy T(1) weighted MRI for planning purposes.
Despite performing well in standard clinical assessments of speech perception, many cochlear implant (CI) users report experiencing significant difficulties when listening in real-world environments. ...We hypothesize that this disconnect may be related, in part, to the limited ecological validity of tests that are currently used clinically and in research laboratories. The challenges that arise from degraded auditory information provided by a CI, combined with the listener's finite cognitive resources, may lead to difficulties when processing speech material that is more demanding than the single words or single sentences that are used in clinical tests.
Here, we investigate whether speech identification performance and processing effort (indexed by pupil dilation measures) are affected when CI users or normal-hearing control subjects are asked to repeat two sentences presented sequentially instead of just one sentence.
Response accuracy was minimally affected in normal-hearing listeners, but CI users showed a wide range of outcomes, from no change to decrements of up to 45 percentage points. The amount of decrement was not predictable from the CI users' performance in standard clinical tests. Pupillometry measures tracked closely with task difficulty in both the CI group and the normal-hearing group, even though the latter had speech perception scores near ceiling levels for all conditions.
Speech identification performance is significantly degraded in many (but not all) CI users in response to input that is only slightly more challenging than standard clinical tests; specifically, when two sentences are presented sequentially before requesting a response, instead of presenting just a single sentence at a time. This potential "2-sentence problem" represents one of the simplest possible scenarios that go beyond presentation of the single words or sentences used in most clinical tests of speech perception, and it raises the possibility that even good performers in single-sentence tests may be seriously impaired by other ecologically relevant manipulations. The present findings also raise the possibility that a clinical version of a 2-sentence test may provide actionable information for counseling and rehabilitating CI users, and for people who interact with them closely.
OBJECTIVES:The increasing numbers of older adults now receiving cochlear implants raises the question of how the novel signal produced by cochlear implants may interact with cognitive aging in the ...recognition of words heard spoken within a linguistic context. The objective of this study was to pit the facilitative effects of a constraining linguistic context against a potential age-sensitive negative effect of response competition on effectiveness of word recognition.
DESIGN:Younger (n = 8; mean age = 22.5 years) and older (n = 8; mean age = 67.5 years) adult implant recipients heard 20 target words as the final words in sentences that manipulated the target word’s probability of occurrence within the sentence context. Data from published norms were also used to measure response entropy, calculated as the total number of different responses and the probability distribution of the responses suggested by the sentence context. Sentence-final words were presented to participants using a word-onset gating paradigm, in which a target word was presented with increasing amounts of its onset duration in 50 msec increments until the word was correctly identified.
RESULTS:Results showed that for both younger and older adult implant users, the amount of word-onset information needed for correct recognition of sentence-final words was inversely proportional to their likelihood of occurrence within the sentence context, with older adults gaining differential advantage from the contextual constraints offered by a sentence context. On the negative side, older adults’ word recognition was differentially hampered by high response entropy, with this effect being driven primarily by the number of competing responses that might also fit the sentence context.
CONCLUSIONS:Consistent with previous research with normal-hearing younger and older adults, the present results showed older adult implant users’ recognition of spoken words to be highly sensitive to linguistic context. This sensitivity, however, also resulted in a greater degree of interference from other words that might also be activated by the context, with negative effects on ease of word recognition. These results are consistent with an age-related inhibition deficit extending to the domain of semantic constraints on word recognition.
Speech prosody, including pitch contour, word stress, pauses, and vowel lengthening, can aid the detection of the clausal structure of a multi-clause sentence and this, in turn, can help listeners ...determine the meaning. However, for cochlear implant (CI) users, the reduced acoustic richness of the signal raises the question of whether CI users may have difficulty using sentence prosody to detect syntactic clause boundaries within sentences or whether this ability is rescued by the redundancy of the prosodic features that normally co-occur at clause boundaries. Twenty-two CI users, ranging in age from 19 to 77 years old, recalled three types of sentences: sentences in which the prosodic pattern was appropriate to the location of a clause boundary within the sentence (congruent prosody), sentences with reduced prosodic information, or sentences in which the location of the clause boundary and the prosodic marking of a clause boundary were placed in conflict. The results showed the presence of congruent prosody to be associated with superior sentence recall and a reduced processing effort as indexed by the pupil dilation. The individual differences in a standard test of word recognition (consonant-nucleus-consonant score) were related to the recall accuracy as well as the processing effort. The outcomes are discussed in terms of the redundancy of the prosodic features, which normally accompany a clause boundary and processing effort.
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