Image-guided radiotherapy supported by surface guidance can help to track lower lung lesions’ respiratory motion while reducing a patient’s exposure to ionizing radiation. However, it is not always ...clear how the skin’s respiratory motion magnitude and its correlation with the lung lesion’s respiratory motion vary between different skin regions of interest (ROI). Four-dimensional computed tomography (4DCT) images provide information on both the skin and lung respiratory motion and are routinely acquired for the purpose of treatment planning in our institution. An analysis of 4DCT images for 57 patients treated in our institution has been conducted to provide information on the respiratory motion magnitudes of nine skin ROIs of the torso, a tracking structure (TS) representing a lower lung lobe lesion, as well as the respiratory motion correlations between the nine ROIs and the TS. The effects of gender and the adipose tissue volume and distribution on these correlations and magnitudes have been analyzed. Significant differences between the ROIs in both the respiratory motion magnitudes and their correlations with the TS have been detected. An overall negative correlation between the ROI respiratory magnitudes and the adipose tissue has been detected for ROIs with rib cage support. A weak to moderate negative correlation between the adipose tissue volume and ROI-to-TS respiratory correlations has been detected for upper thorax ROIs. The respiratory magnitudes in regions without rib support tend to be larger for men than for women, but no differences in the ROI-to-TS correlation between sexes have been detected. The described findings should be considered when choosing skin surrogates for lower lung lesion motion management.
(1) Background: The aim of this study was to evaluate the efficacy and safety of SABR for LAPC using Calypso® Extracranial Tracking for intrafractional, fiducial-based motion management, to present ...this motion management technique, as there are yet no published data on usage of Calypso® during SABR for LAPC, and to report on our clinical outcomes. (2) Methods: Fifty-four patients were treated with SABR in one, three, or five fractions, receiving median BED10 = 112.5 Gy. Thirty-eight patients received systemic treatment. End points were OS, FFLP, PFS, and toxicity. Actuarial survival analysis and univariate analysis were investigated. (3) Results: Median follow-up was 20 months. Median OS was 24 months. One-year FFLP and one-year OS were 100% and 90.7%, respectively. Median PFS was 18 months, and one-year PFS was 72.2%. Twenty-five patients (46.3%) were alive at the time of analysis, and both median FU and OS for this subgroup were 26 months. No acute/late toxicity > G2 was reported. (4) Conclusions: SABR for LAPC using Calypso® presented as an effective and safe treatment and could be a promising local therapeutic option with very acceptable toxicity, either as a single treatment or in a multimodality regimen. Dose escalation to the tumor combined with systemic treatment could yield better clinical outcomes.
(1) Background: the aims of this study were to determine the total extent of pancreatic cancer's internal motions, using Calypso
extracranial tracking, and to indicate possible clinical advantages of ...continuous intrafractional fiducial-based tumor motion tracking during SABR. (2) Methods: thirty-four patients were treated with SABR for LAPC using Calypso
for motion management. Planning MSCTs in FB and DBH, and 4D-CTs were performed. Using data from Calypso
and 4D-CTs, the movements of the lesions in the CC, AP and LR directions, as well as the volumes of the 4D-CT-based ITV and the volumes of the Calypso
-based ITV were compared. (3) Results: significantly larger medians of tumor excursions were found with Calypso
than with 4D-CT: CC: 29 mm (
< 0.001); AP: 14 mm (
< 0.001) and LR: 11 mm (
< 0.039). The median volume of the Calypso
-based ITV was significantly larger than that of the 4D-CT based ITV (
< 0.001). (4) Conclusion: beside known respiratory-induced internal motions, pancreatic cancer seems to have significant additional motions which should be considered during respiratory motion management. Only direct and continuous intrafractional fiducial-based motion tracking seems to provide complete coverage of the target lesion with the prescribed isodose, which could allow for safe tumor dose escalation.
Delivering focused radiation doses via linear accelerators is a crucial component of stereotactic radiosurgery (SRS) for brain metastases. The Varian Edge linear accelerator provides highly conformal ...radiation therapy through a high-definition multi-leaf collimator (HD120 MLC) and conical collimator (CC). HD120 MLC adapts to the shape of the target volume using movable tungsten leaves, while CC has a block of conical shape (cones). CC in SRS treatments of small brain metastases is preferred due to its mechanical stability and steeper dose fall-off, potentially sparing organs at risk (OARs) and the brain better than HD120 MLC. This study aims to determine if CC offers significant advantages over HD120 MLC for SRS treatments. For 116 metastatic lesions, CC and HD120 MLC treatment plans were created in Varian Eclipse TPS and compared based on various dose parameters, robustness tests, and QA measurements. The results indicate that CC provides no significant advantages over HD120 MLC, except for slight, clinically insignificant benefits in brain sparing and dose fall-off for the smallest lesions. HD120 MLC outperforms CC in almost every aspect, making it a better choice for irradiating brain metastases with 0.1 cm
or higher volumes.
Purpose: To assess the efficacy and safety of stereotactic body radiotherapy for patients with unresectable, locally advanced pancreatic cancer using Optical Surface Management System - AlignRT ...(OSMS-AlignRT) as an optical body surface motion management in deep breath hold. Patients and Methods: Forty-five patients diagnosed with locally advanced pancreatic cancer were treated with stereotactic body radiotherapy in 3 or 5 fractions, and received varying BED.sub.10 (median 79.5 Gy) from April 2017 to December 2020. All patients were treated in deep breath hold with OSMS-AlignRT used as optical body surface motion management. Thirty-three patients received systemic treatment before and/or after stereotactic body radiotherapy, and twelve patients received no systemic treatment. In this retrospective, observational, single-arm study, primary endpoints were overall survival and freedom from local progression (ie, local control). Secondary endpoints were progression-free survival and toxicity. Actuarial survival analysis and univariate analysis were investigated. Results: Data from forty-five patients were analyzed. Median follow-up was 15 months. One-year freedom from local progression and survival were 95.5% and 71.1%, respectively. Median progression-free survival was 14 months. Median overall survival from diagnosis for all patients was 17 months, and 19 months for patients alive at the time of analysis. No patient had >G2 toxicity. Conclusion: Stereotactic body radiotherapy for locally advanced pancreatic cancer using OSMS-AlignRT as optical body surface motion management in deep breath hold patients is an effective and safe local treatment option, with no >G2 toxicity, and could be a promising therapeutic option with acceptable toxicity, either as a single treatment or in a multimodal regimen. OSMS-AlignRT provided accurate and reliable body surface motion management during stereotactic body radiotherapy. Keywords: AlignRT, locally advanced pancreatic cancer, Optical Surface Management System, pancreatic SBRT, surface guided radiotherapy Plain Language Summary * Patients diagnosed with unresectable, locally advanced pancreatic cancer represent a particular problem in oncology, due to the challenges in local treatment. * As there are still no published data on OSMS-AlignRT as optical body surface motion management during stereotactic body radiotherapy for locally advanced pancreatic cancer, our study aimed to evaluate the efficacy and safety of this treatment approach. * During stereotactic body radiotherapy, OSMS-AlignRT reliably monitors both steadiness of patients' deep breath hold and all additional possible movements (eg, drifts). * The tumor and organs at risk are more clearly visible on planning MSCT and on daily cone beam CT scans in deep breath hold, which makes contouring, treatment planning, and daily image guidance easier and more reliable compared with free breathing. * During the treatment in deep breath hold, the organs at risk move away from the tumor, which makes them easier to spare from excess of radiation. * Stereotactic body radiotherapy in deep breath hold requires compliant patient to be adequately conducted. * Stereotactic body radiotherapy as a local treatment for locally advanced pancreatic cancer using OSMS-AlignRT for body surface motion management presented in our study as an effective, safe, and well tolerated option with favorable clinical outcomes: median overall survival was 17 months, 1-year local control and 1-year survival were 95.5% and 71.1%, respectively, with no > G2 toxicity.
Tijekom radioterapije u gotovo svih bolesnika se u većoj ili manjoj mjeri pojavljuju upalne kožne reakcije. Transdermalni gubitak vlage – dehidracija kože kao jedna od posljedica iradijacije, ...pogoduje nastanku upalnih reakcija, pojačava simptome i usporava oporavak kože. Preparat Excipial U Lipolotion, V/U emulzija s 4%-tnim udjelom uree rehidrira kožu i smanjuje transdermalni gubitak vlage. Preparati s 3–4%-tnim udjelom uree u dosadašnjim su se kliničkim istraživanjima pokazali učinkovitim sredstvima u liječenju upalnih kožnih reakcija. Temeljem toga proveli smo istraživanje u kojem smo primijenili preparat Excipial U Lipolotion na kožu bolesnika na radioterapiji, koji su imali izražene upalne kožne reakcije. U istraživanje su bili uključeni bolesnici s tumorima glave i vrata te dojke. Procjena učinkovitosti
preparata provedena je na temelju liječnikove kliničke prosudbe subjektivnih parametara stanja kože i pitanja upućenih bolesniku smatra li da mu preparat pomaže. Došli smo do zaključka da preparat Excipial U Lipolotion povoljno djeluje na upalne kožne reakcije, osobito na suhe upalne reakcije. U većine bolesnika na radioterapiji preparat brzo i znatno smanjuje i subjektivne tegobe – svrbež, pečenje, bolnost. Budući da su parametri procjene bili subjektivni, potrebno je daljnje istražiti učinak Excipial U Lipolotiona temeljem objektivnih kliničkih pokazatelja – mjerenja crvenila i stupnja vlažnosti kože tijekom primjene preparata.
Combining experimental studies on grain yield variability with crop model simulations in maize could assist in choosing the optimum maturity group for a certain location, counteracting the effect of ...climate change. However, studies considering specificities in Southeast Europe are lacking. The objectives were to put various environmental covariates including stress degree days (SDD) into FAO maturity settings to determine the impact of climate change on maize growing in Southeast Europe and to compare trends for grain yields over twenty years of maize experimental and simulation data grouped in five FAO maturity groups (FAO 200–FAO 600). Pre-registration yield trials of maize planted in one location in Croatia grown from 1996 to 2015 were used to determine “potential yield”. Correlation coefficients between 12 climate covariates and grain yield (GY) across the maturity groups revealed the tightest negative associations between SDD and GY that were weakened by later-maturity groups. Similar trends in GY were obtained by both experimental and simulation data, highlighting FAO 600 as a nearly no yield-reducing FAO group over the two decades. Our results indicate that choosing early maize hybrids in Southeast Europe does not seem to be an optimum option in the future, since these hybrids are more sensitive to omnipresent heat stress than late hybrids.
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