Technology in Cancer Research & Treatment最新文献

PurposeThis study assessed dosimetric effects of setup errors on boost target volume (PTVboost) coverage using simultaneous integrated boost (SIB) in early-stage left-sided breast cancer.Methods35 patients who received whole-breast radiotherapy (40.0 Gy/15 Fr) combined with a SIB to the tumor bed (48.0 Gy/15 Fr) were retrospectively analyzed. Translational-rotational coupled errors (1.0°rotation paired with 1.0 mm translation, 2.0° with 2.0 mm, 3.0° with 3.0 mm) were simulated about all axes. The D95 (dose to 95% of the PTVboost) and V95 (volume covered by 95% of the prescribed dose) were assessed through multivariate analysis to explore the relationship between PTVboost coverage and various anatomy factors, including the volume of the PTVboost (V_boost), the distance from the PTVboost centroid to the isocentre (D_iso), the mean depth from the anterior edge of PTVboost to the body surface (S_Depth), and setup errors.ResultsUnder a combination of 1.0° rotation and 1.0 mm setup errors, the D95 values and V95 coverage of the PTVboost were ≥95% in all cases. However, when the error combination increased to 2.0°:2.0 mm, there was a significant decrease in coverage, with approximately 80% of the target areas exhibiting D95 and V95 values <95%. When the setup errors further increased to 3.0°:3.0 mm, D95 and V95 values were <95% in all cases. Multivariate analysis indicated that V_boost, D_iso, and S_Depth were significant predictors of target coverage.ConclusionPTVboost dose coverage risk were synergistically influenced by increasing D_iso, reduced V_boost, and shorter S_Depth. The multivariate model may stratify coverage risk categories using tumor anatomy and setup error magnitudes.

PurposeIn our institute, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) were performed by Cyberknife-S7 (CK-S7) which provided the selection of different collimators. This study aimed to compare critical plan qualities including conformality, high-dose area, dose fallout, and treatment efficiency between InCise™ multileaf collimator (MLC) based and Iris™ variable aperture collimators (Iris) based treatment plans.MethodsTwenty-five patients with intracranial tumors treated with CK-S7 were retrospectively analyzed. The Precision 3.3.0.0 with VOLO™ optimizer and GPU-accelerated Monte Carlo dose calculation algorithm was used for treatment planning. The new conformality index (nCI), homogeneity index (HI), high-dose ratio (HDR) and distribution inside plan target volume (PTV), dose gradient distance (DGD) outside PTV, organs at risk (OARs) sparing, and treatment efficiency were compared between MLC based and Iris based plans.ResultsMLC plan achieved higher nCI, higher HDRs from 135% prescription dose (PD) to 110%PD and trended to form more centralized and gathered high-dose distribution inside PTV, while no statistical difference was found in HI. Iris possessed better dose-engraving ability around the target boundary especially when it close to OARs with strict dose constraints. MLC plan showed shorter DGD from 90%PD to 20%PD. MLC plan achieved less MUs (-67.14%), less nodes (-41.5%), less beams (-74.06%) and shorter treatment time (-51.64%). There were positive correlations between the effective radius of PTV (rPTV) and DGD from 90%PD to 10%PD both in MLC and Iris plans.ConclusionsMLC plan achieved comparable conformality, higher HDRs, more gathered high-dose distribution, faster dose fallout and more efficient treatment which proved it an excellent SRS/SRT choice for intracranial tumors treated with CK-S7. MLC might take an important advantage for the uncompliant and painful patients. However, Iris showed a better dose-engraving ability, it might be taken into consideration especially when the tumor was close to OARs with strict dose constraints.

IntroductionThis study aims to investigate and fairly compare the oncological therapeutic efficacy of red photodynamic therapy (Red-PDT) and near-infrared photodynamic therapy (NIR-PDT), to support the selection of suitable photosensitizers (PSs) for optimal PDT.MethodsTwo different representative PSs, trastuzumab-HiLyte Fluor™ 647 conjugate (Tra-HLF647) and trastuzumab-Indocyanine Green conjugate (Tra-ICG), activated by two laser systems at 635 nm and 808 nm, respectively, were used. To ensure a fair comparison, we used the same A4 cell line/tumor model expressing the same target, human epidermal growth factor receptor 2 (HER-2), and employed the same delivery approach. To comprehensively evaluate and compare the potential effects of Tra-HLF647-mediated Red-PDT and Tra-ICG-mediated NIR-PDT, we conducted cell viability imaging assays, intracellular reactive oxygen species (ROS) generation measurements, longitudinal monitoring of tumor volume changes, histological and immunohistochemical (IHC) analyses of tumor sections, and measurements of tumor necrotic depth.ResultsBoth PDTs exerted similar rapid cell death in cell viability imaging assays. There was no significant difference in ROS generation between cells subjected to Red-PDT and NIR-PDT. Both PDTs caused a statistically significant tumor growth delay compared to the control groups; however, no significant difference was detected between the Red-PDT and NIR-PDT groups. The H&E-stained sections of tumors that received Red-PDT and NIR-PDT showed a similar pattern of necrosis-associated features. No conspicuous tissue damage was observed in the control groups. The depth of necrosis, estimated via the coincided accumulation of a fluorescent necrosis marker (AF546-pHLIP) and utilized as an indirect index to approximate laser light penetration, was also nearly identical between tumors treated with Red-PDT and NIR-PDT.ConclusionsTarget-specific Red-PDT and NIR-PDT, using their respective PSs, demonstrated equivalent therapeutic efficacy in tumor models. These findings suggest that wavelength differences between Red-PS and NIR-PS may not critically impact treatment outcomes, offering flexibility in fluorophore selection for future PS conjugate design.

IntroductionThis study aimed first to quantify the impact of varying concentrations of iodine contrast agents on electron density (ED) values of ED maps through phantom experiments and evaluate the differences in dose calculations; Second, to validate that utilizing ED maps for photon dose calculation can minimize the uncertainties introduced by the iodine contrast agents by using actual patients' data.MethodsA phantom with iodine inserts of varying concentrations was scanned using a spectral CT to acquire post-contrast and non-contrast CT images and the corresponding ED maps. The data of 22 patients with pelvic tumors were selected retrospectively for clinical validation. Treatment plans were transplanted to non-contrast and post-contrast ED maps, and the dose distributions were then recalculated. The differences in dose-volume histogram (DVH) parameters between the plans based on non-contrast and post-contrast ED maps were compared. Besides, gamma analysis was performed to evaluate the discrepancies in dose distributions between these two plans.ResultsFor the phantom experiment, under clinical organ perfusion concentrations (≤5.0 mg/ml), the maximum increase in HU values reached 145.76, whereas the ED values showed only a 1.54% increase. Compared to the non-contrast images, the maximum dose difference of the post-contrast CT image was 2.3%, while the post-contrast ED map was only 0.2%. For comparison of treatment plans based on patients' non-contrast and post-contrast ED maps, only the bladder's D50% showed a statistically significant difference, but the difference in value remained clinically negligible. The remaining showed no statistically significant differences.ConclusionThe influence of iodine contrast agents on the ED values is minimal. Dose calculations based on ED maps can significantly reduce the errors introduced by contrast agents. This approach would allow us to depend solely on a single post-contrast scan for radiotherapy simulation, thereby minimizing imaging radiation exposure and improving simulation efficiency.

IntroductionDespite technological advances in radiotherapy, trismus persists as a treatment-limiting toxicity in T3-T4 nasopharyngeal carcinoma (NPC) survivors, with current guidelines lacking evidence-based dose constraints for masticatory muscle sparing. This study aimed to establish dose-response relationships and propose clinically actionable thresholds for trismus prevention using volumetric modulated arc therapy (VMAT) with collapsed cone convolution (CCC) dose calculation.MethodsIn this retrospective cohort study, 60 T3-T4 NPC patients treated with VMAT (CCC algorithm) were stratified by trismus severity. Dosimetric parameters (Dmean/Dmax) of jaw-opening (digastric, mylohyoid, geniohyoid) and closing muscles (masseter, pterygoids) were analyzed. Univariate (t-tests) and multivariable logistic regression identified predictors; ROC curves determined optimal dose constraints.ResultsUnivariate analysis: digastric Dmean showed the strongest association with trismus (p = .0049), followed by mylohyoid Dmean (p = .088) and masseter Dmean (p = .063). Multivariable analysis: digastric Dmean retained marginal significance (β=-1.58 × 10^-3, p = .092), with each 1 Gy increase reducing trismus odds. ROC analysis: digastric Dmean (AUC = 0.70) and mylohyoid Dmean (AUC = 0.60) yielded optimal thresholds of ≤26 Gy and ≤28 Gy, respectively (Youden's index).ConclusionProactive sparing of jaw-opening muscles-particularly the digastric (Dmean ≤26 Gy) and mylohyoid (Dmean ≤28 Gy)-during VMAT planning may mitigate trismus risk in advanced NPC. These preliminary constraints, derived from CCC-optimized dosimetry and based on optimal classification cutoffs (Youden's index), help address a critical gap in current OAR protocols.

IntroductionLocally advanced rectal cancer (LARC) remains a therapeutic challenge, with significant risks of both locoregional and distant relapse. Total neoadjuvant therapy (TNT), which combines induction chemotherapy and chemoradiotherapy (CRT) prior to surgery, has emerged as a potentially more effective strategy than traditional approaches, yet data from low- and middle-income countries (LMICs) remain limited. This study evaluates the efficacy and toxicity of induction FOLFIRINOX followed by concurrent CRT in Vietnamese patients with lower-middle LARC.MethodsA retrospective analysis was conducted on adult patients (n = 72) with clinical stage T3-T4 M0 rectal adenocarcinoma. All patients received induction FOLFIRINOX for six cycles and preoperative CRT, followed by total meso-rectal excision (TME), and adjuvant chemotherapy as indicated. The primary endpoint was pathologic complete response (pCR, ypT0N0); secondary endpoints were 3-year disease-free survival (DFS) and safety. The study conforms to STROBE guidelines.ResultsPathological complete response was achieved in 25.0% of patients. The 3-year DFS reached 90.6%. Treatment feasibility was high, with 93.06% completing all 6 induction cycles; hematologic adverse events, particularly leukopenia and neutropenia, were the most common toxicities but were generally manageable with supportive care, while nonhematological toxicities were predominantly mild. R0 resection rate was 100% and sphincter-preserving surgery was 86.1%.ConclusionIn a LMIC setting, induction FOLFIRINOX followed by CRT shows promising efficacy and tolerable toxicity in LARC. These findings support early, intensified systemic therapy to enhance local control and mitigate metastatic spread.

Introduction: Metastasis remains a major cause of death among patients with malignant tumors. Radiotherapy is one of the main modalities of cancer treatment. The rapid development of radiotherapy technology has enabled the widespread application of hypofractionated radiotherapy (HFRT) in clinical practice. This study aimed to evaluate the effect of HFRT on the survival and safety of patients with oligometastatic tumors.

Methods: We conducted a retrospective study that involved 65 patients with well-controlled primary tumors and 1-5 metastatic foci treated at the study site between January 2020 and December 2022. Patients were aged >18 years and had a ≥ 6-month life expectancy. The patients received standard treatments plus HFRT for all metastatic foci. The dose fractionation regimen was adjusted according to the location and size of the patient's metastatic foci. The planning gross tumor volume of HFRT was 82.93 cm³ (range: 10.12-562.80 cm³), and the radiation dose range was 20 Gy/5 F-60 Gy/15 F. Progression-free survival (PFS), overall survival (OS), local control rates, and incidence of adverse events of the patients were observed.

Results: Among the 65 patients, the median follow-up time, PFS, and OS were 26 months (95% CI: 0.80-37.50), 15 months (95% CI: 9.36-20.64), and 28 months (95% CI: 16.71-39.29), respectively. The 1- and 2-year PFS were 53.8% and 40.0%, respectively, while the 1- and 2-year OS rates were 73.8% and 56.9%, respectively. In total, 13.8%, 55.4%, 20.0%, and 13.8% of patients showed complete response, partial response, stable disease, and progressive disease, respectively. Four patients developed grade 3 or worse adverse events, and no treatment-related deaths occurred.

Conclusions: HFRT showed favorable clinical efficacy and safety in patients with oligometastatic tumors, generally achieving a good OS rate. Further randomized trials should be conducted.

ObjectiveTo assess the efficiency of extracellular volume (ECV) derived from equilibrium computed tomography (CT) in predicting recurrence-free survival (RFS) and overall survival (OS) after R0 resection of pancreatic ductal adenocarcinoma (PDAC).MethodsThis retrospective study included 83 patients who underwent CT and R0 resection between January 2016 and September 2023. The pattern of tumor recurrence and prognosis were recorded for each patient. Tumor recurrence was classified into three groups: isolated local recurrence group, distant recurrence group and censored group. The associations between the CT-ECV and clinicopathological features and recurrence pattern of PDAC were evaluated by chi-squared test. Multivariable Cox proportional-hazards models were conducted to evaluate the effects of clinical factors, CT features and CT-ECV on RFS and OS.ResultsThe median RFS and OS were 10.7 and 17.1 months, respectively. On multivariate analysis, the CT-ECV and adjacent organ invasion were found to be associated with RFS (HR, 0.968, P = .017; HR, 0.453; P = .006), and only the CT-ECV was an independent prognostic factor for OS (HR, 0.968; P = .022). Low CT-ECV group was significantly associated with elevated CA19-9, larger tumor size, G3 (tumor grade) and II/III (AJCC tumor stage) (P < .05). In the recurrence pattern analysis, the CT-ECV did not exhibit an association between local recurrence and non-local recurrence groups (P = .455), while patients in the low CT-ECV group were more inclined to experience distant recurrence after curative surgery (P = .037).ConclusionsCT-ECV determined by equilibrium contrast-enhanced CT was a useful imaging biomarker for predicting distant recurrence and survival in resectable PDAC patients, which may facilitate further risk stratification and personalized care.

Multiple myeloma (MM) is a malignant hematological disease originating from plasma cells that remains incurable. Autologous stem cell transplantation (ASCT) is an important treatment method for MM. With the development of new drugs, the treatment of MM patients who meet the ASCT criteria has significantly improved, and the median survival time has increased by 8-10 years. The current treatment for MM patients who meet the ASCT criteria consists mainly of the following stages: induction therapy, stem cell collection, stem cell transplantation, and consolidation and maintenance therapy. Even today, long-term disease control remains the goal of MM treatment in clinical practice. In the era of new drugs, early ASCT still results in longer progression-free survival (PFS) and is currently the standard treatment method for young newly diagnosed multiple myeloma (NDMM) patients. Moreover, tandem transplantation can be considered for MM patients with high-risk cytogenetics. This review discusses mainly the role of ASCT in MM, the conditions for patient transplantation, the induction chemotherapy regimen before transplantation, the conditioning regimen, the timing of transplantation, and the effectiveness of tandem transplantation, including maintenance and salvage ASCT after transplantation.