Immune Response and Immune Checkpoint Molecules in Patients with Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy: A Review.

It is well-established that tumor antigens and molecules expressed and secreted by cancer cells trigger innate and adaptive immune responses. These two types of anti-tumor immunity lead to the infiltration of the tumor's microenvironment by immune cells with either regulatory or cytotoxic properties. Whether this response is associated with tumor eradication after radiotherapy and chemotherapy or regrowth has been a matter of extensive research through the years, mainly focusing on tumor-infiltrating lymphocytes and monocytes and their subtypes, and the expression of immune checkpoint and other immune-related molecules by both immune and cancer cells in the tumor microenvironment. A literature search has been conducted on studies dealing with the immune response in patients with rectal cancer treated with neoadjuvant radiotherapy or chemoradiotherapy, assessing its impact on locoregional control and survival and underlying the potential role of immunotherapy in the treatment of this cancer subtype. Here, we provide an overview of the interactions between local/systemic anti-tumor immunity, cancer-related immune checkpoint, and other immunological pathways and radiotherapy, and how these affect the prognosis of rectal cancer patients. Chemoradiotherapy induces critical immunological changes in the tumor microenvironment and cancer cells that can be exploited for therapeutic interventions in rectal cancer.

Host cystathionine-γ lyase derived hydrogen sulfide protects against Pseudomonas aeruginosa sepsis.

Hydrogen sulfide (H2S) has recently been recognized as a novel gaseous transmitter with several anti-inflammatory properties. The role of host- derived H2S in infections by Pseudomonas aeruginosa was investigated in clinical and mouse models. H2S concentrations and survival was assessed in septic patients with lung infection. Animal experiments using a model of severe systemic multidrug-resistant P. aeruginosa infection were performed using mice with a constitutive knock-out of cystathionine-γ lyase (Cse) gene (Cse-/-) and wild-type mice with a physiological expression (Cse+/+). Experiments were repeated in mice after a) treatment with cyclophosphamide; b) bone marrow transplantation (BMT) from a Cse+/+ donor; c) treatment with H2S synthesis inhibitor aminooxyacetic acid (ΑΟΑΑ) or propargylglycine (PAG) and d) H2S donor sodium thiosulfate (STS) or GYY3147. Bacterial loads and myeloperoxidase activity were measured in tissue samples. The expression of quorum sensing genes (QS) was determined in vivo and in vitro. Cytokine concentration was measured in serum and incubated splenocytes. Patients survivors at day 28 had significantly higher serum H2S compared to non-survivors. A cut- off point of 5.3 µΜ discriminated survivors with sensitivity 92.3%. Mortality after 28 days was 30.9% and 93.7% in patients with H2S higher and less than 5.3 µΜ (p = 7 x 10-6). In mice expression of Cse and application of STS afforded protection against infection with multidrug-resistant P. aeruginosa. Cyclophosphamide pretreatment eliminated the survival benefit of Cse+/+ mice, whereas BMT increased the survival of Cse-/- mice. Cse-/- mice had increased pathogen loads compared to Cse+/+ mice. Phagocytic activity of leukocytes from Cse-/- mice was reduced but was restored after H2S supplementation. An H2S dependent down- regulation of quorum sensing genes of P.aeruginosa could be demonstrated in vivo and in vitro. Endogenous H2S is a potential independent parameter correlating with the outcome of P. aeruginosa. H2S provides resistance to infection by MDR bacterial pathogens.

Isodose surface differences: A novel tool for the comparison of dose distributions.

BACKGROUND: Comparing dose distributions is a routine task in radiotherapy, mainly in patient-specific quality assurance (PSQA). Currently, the evaluation of the dose distributions is being performed mainly with statistical methods, which could underestimate the clinical importance of the spotted differences, as per the literature. PURPOSE: This paper aims to provide proof-of-concept for a novel dose distribution comparison method based on the difference of the isodose surfaces. The new method connects acceptance tolerance to QA limitations (equipment capabilities) and integrates a clinical approach into the analysis procedure. METHODS: The distance of dose points from the isocenter can be used as a function to define the shape of an isodose surface expressed as a histogram. Isodose surface differences (ISD) are defined as the normalized differences of reference and evaluated surface histograms plotted against their corresponding isodose. Acceptance tolerances originate from actual QA tolerances and are presented clinically intuitively. The ISD method was compared to the gamma index using intentionally erroneous VMAT and IMRT plans. RESULTS: Results revealed that the ISD method is sensitive to all errors induced in the plans. Discrepancies are presented per isodose, enabling the evaluation of the plan in two regions representing PTV and Normal Tissue. ISD manages to flag errors that would remain undetected under the gamma analysis. CONCLUSION: The ISD method is a meaningful, QA-related, registration-free, and clinically oriented technique of dose distribution evaluation. This method can be used either as a standalone or an auxiliary tool to the well-established evaluation procedures, overcoming significant limitations reported in the literature.

Dosimetric comparison and evaluation of two computational algorithms in VMAT treatment plans.

PURPOSE: This study aimed to assess the accuracy and dosimetric impact of the Acuros XB (AXB) algorithm compared to the Anisotropic Analytical Algorithm (AAA) in two situations. First, simple phantom geometries were set and analyzed; moreover, volumetric modulated arc therapy (VMAT) clinical plans for Head & Neck and lung cases were calculated and compared. METHODS: First, a phantom study was performed to compare the algorithms with radiochromic EBT3 film doses using one PMMA slab phantom and two others containing foam or air gap. Subsequently, a clinical study was conducted, including 20 Head & Neck and 15 lung cases irradiated with the VMAT technique. The treatment plans calculated by AXB and AAA were evaluated in terms of planning target volume (PTV) coverage (V95% ), dose received by relevant organs at risk (OARs), and the impact of using AXB with a grid size of 1 mm. Finally, patient-specific quality assurance (PSQA) was performed and compared for 17 treatment plans. RESULTS: Phantom dose calculations showed a better agreement of AXB with the film measurements. In the clinical study, AXB plans exhibited lower Conformity Index and PTV V95% , higher maximum PTV dose, and lower mean and minimum PTV doses for all anatomical sites. The most notable differences were detected in regions of intense heterogeneity. AXB predicted lower doses for the OARs, while the calculation time with a grid size of 1 mm was remarkably higher. Regarding PSQA, although AAA was found to exhibit slightly higher gamma passing rates, the difference did not affect the AXB treatment plan quality. CONCLUSIONS: AXB demonstrated higher accuracy than AAA in dose calculations of both phantom and clinical conditions, specifically in interface regions, making it suitable for sites with large heterogeneities. Hence, such dosimetric differences between the two algorithms should always be considered in clinical practice.

Prostate Cancer Stem Cells: Biology and Treatment Implications.

Stem cells differentiate into mature organ/tissue-specific cells at a steady pace under normal conditions, but their growth can be accelerated during the process of tissue healing or in the context of certain diseases. It is postulated that the proliferation and growth of carcinomas are sustained by the presence of a vital cellular compartment resembling stem cells residing in normal tissues: 'stem-like cancer cells' or cancer stem cells (CSCs). Mutations in prostate stem cells can lead to the formation of prostate cancer. Prostate CSCs (PCSCs) have been identified and partially characterized. These express surface markers include CD44, CD133, integrin α2ß1, and pluripotency factors like OCT4, NANOG, and SOX2. Several signaling pathways are also over-activated, including Notch, PTEN/Akt/PI3K, RAS-RAF-MEK-ERK and HH. Moreover, PCSCs appear to induce resistance to radiotherapy and chemotherapy, while their presence has been linked to aggressive cancer behavior and higher relapse rates. The development of treatment policies to target PCSCs in tumors is appealing as radiotherapy and chemotherapy, through cancer cell killing, trigger tumor repopulation via activated stem cells. Thus, blocking this reactive stem cell mobilization may facilitate a positive outcome through cytotoxic treatment.

Low dose total skin electron beam therapy for the management of T cell cutaneous lymphomas.

Mycosis fungoides (MF) represent the most common type of primary cutaneous lymphomas. Total skin electron beam (TSEB) therapy to a total skin administered dose of 36 Gy represents a very effective treatment regimen and its role in the management of MF is well established. Unfortunately, the issue in MF is that despite the proved effectiveness of radiation therapy, disease regress, and the main goal of TSEB treatment seems to be the prolongation of the overall response duration time. Taking into consideration the high radio-sensitivity of the disease, lower radiation doses have been tested with acceptable and comparable results. We prospectively analyzed low dose TSEB in 14 patients treated at ATTIKON University Hospital from 2011 to 2017. After a median duration of follow up time of 39 months we found that low dose TSEB is an effective treatment option, since therapeutic results are more than acceptable, with minimal toxicity. The fact that it can be repeated safely in the natural course of a "regressive" disease makes it more attractive than the standard full dose scheme of 36 Gy.

First application of hemi-body electron beam irradiation for Kaposi sarcoma at the lower extremities.

Kaposi's sarcoma (KS) is a systemic neoplastic disease that can present cutaneous symptoms and is usually treated with a systematic approach due to its extent. Due to its radiosensitivity, radiotherapy is considered one of its main treatments, for palliation and local control of the skin and mucosal lesions. The aim of this paper was to report the first case of KS treated by hemi-body electron irradiation protocol in Greece. A fractionated 40 Gy hemi-body electron irradiation was prescribed to a 60-year-old male patient with KS at his legs. Dose uniformity was verified on a daily basis by thermoluminescence dosimetry (TLD). The treatment resulted to complete clinical response. Limited irradiation-derived side effects appeared. This is the first case ever to be treated with hemi-body electron irradiation protocol in Greece. To the best of our knowledge, this is also the first time that a single field hemi-body electron beam irradiation at a total skin electron beam (TSEB)-like configuration is reported to be used for KS.

Quality assurance protocol for superficial and deep hyperthermia systems established by the Hellenic Association of Medical Physicists (HAMP) in cooperation with the Hellenic Society of Oncologic Hyperthemia (HSOH): A study based on European Society for Hyperthermic Oncology (ESHO) quality assurance guidelines.

PURPOSE: During the last years hyperthermia is a developing therapeutic modality in Greece. Quality assurance (QA) procedures are essential for ensuring the correct operation of the hyperthermia system and therefore the selective heating of the tumor with minimum toxicity to the surrounding healthy tissues. The European Society for Hyperthermic Oncology (ESHO) has proposed QA guidelines for superficial as well as deep hyperthermia systems. The purpose of this study was to describe the adapted QA protocol for superficial and deep hyperthermia systems established in Greece. METHODS: A working group was created by the Hellenic Association of Medical Physicists (HAMP) for the proposal of QA guidelines for superficial and deep hyperthermia systems. A review of the protocol proposed by ESHO, together with the existing protocols in other European and International centers, as well as protocols suggested by European or International organizations, was performed. Then, a protocol was suggested, describing procedures for QA according to the current technology and the existing equipment used in Greece. RESULTS: A protocol describing the procedures for QA of superficial and deep hyperthermia systems was proposed. These procedures aim to evaluate the correct operation of the device, the thermometric system, the generator, the incorporated power meter and the applicators. It will also ensure the electrical safety of the devices. CONCLUSIONS: The proposed protocol, applied by medical physicists in Greece, will ensure an efficient treatment with safety and minimum adverse effects. This protocol has been approved by the Hellenic Society of Oncologic Hyperthermia and the Hellenic Association of Medical Physicists.

Determination of beam profile characteristics in radiation therapy using different dosimetric set ups.

PURPOSE: The purpose of this study was to analyze and to compare results regarding the penumbra size, flatness and symmetry obtained using six different measuring systems. METHODS: Beam profile measurements were performed in standard water phantom set-up for two photon beams for various square field sizes and for five electron beams for several applicator sizes at several depths. Six measuring systems were used: three ionization chambers; a Semiflex (31002, PTW), a Markus (23343, PTW) and a Roos (34001, PTW); Two semiconductor detectors; a p-type diode (60008, PTW) and an e-type diode (60017, PTW) and a one dimensional Linear Array (LA48, PTW). RESULTS: Our results indicate that penumbra size determination is strongly dependent on the measuring system. For the photon measurements the diodes showed the narrowest penumbra followed by the LA48, while the largest penumbra was presented by the Semiflex. The unshielded diode overestimates the penumbra in large field sizes and big depths. The parallel plate ionization chambers overestimate the penumbra width of electron beam profiles. The LA48 presents the most symmetric beam profiles. CONCLUSIONS: Regarding penumbra size determination, the LA48 can be considered acceptable in terms of accuracy, and is the most time-effective system. It is also adequate for symmetry and flatness measurements. For greatest possible accuracy silicon diode is recommended. Parallel plate ionization chambers are not appropriate for penumbra measurements.

A five split-field three dimensional conformal technique versus an anterior-posterior on in postoperative radiotherapy for gastric carcinoma: a multicenter comparative study using quality of life measurements as well as clinical and dosimetric parameters.

PURPOSE: Several adjuvant approaches are regarded as available options in the management of localized, resectable gastric cancer .The objective of our study was to evaluate multiple field and anteroposterior conformal technique. METHODS: Ninety-seven patients received three dimensional conformal (3DCRT) postoperative adjuvant radiation therapy for gastric carcinoma. Thirty-five patients received anteroposterior (AP/PA) fields (Group B), while 62 patients were irradiated with multifield technique (Group A). Their ages ranged between 29-85 years. The objective of the study was to evaluate the quality of life (QoL) for all patients after the completion of radiotherapy using the QLQ-C30 of the EORTC questionnaire (European Organization for Research and Treatment of Cancer) and to investigate any measurable differences between those two radiation techniques according to QUANTEC criteria and the radiotoxicity. RESULTS: In terms of QUANTEC criteria, the multifield technique was superior concerning the left kidney (p=0.025), right kidney (p<0.001), spinal cord (p<0.001) and planning target volume (PTV) coverage (p<0.001). According to EORTC/ RTOG toxicity criteria, the rate of diarrhea was higher in AP/ PA technique (p=0.028). In terms of QLQ-C30, the multifield technique was superior concerning appetite loss (p=0.022), diarrhea (p=0.046) and global QoL (p<0.001). CONCLUSION: On the basis of QLQ-C30 questionnaire, EORTC/ RTOG toxicity and dosimetric parameters, the present report has shown that the three dimensional multifield conformal radiotherapy is superior compared to AP-PA techniques.

Toxicity and efficacy of a hypofractionated (3 weekly fractions of 850c Gy) irradiation schedule for stage IIIb / IV non-small cell lung cancer elderly patients with low performance status and unfit for chemotherapy.

PURPOSE: To evaluate in an observational way the clinical impact of a hypofractionated irradiation schedule in patients with unresectable non-small cell lung cancer (NSCLC). METHODS: Forty elderly patients (24 men/16 women) diagnosed with unresectable stage IIIb/IV NSCLC unfit for chemotherapy, were treated with once-a-week hypofractionation schedule. All patients had a poor performance status. A dose of 255 Gy in 3 weekly fractions was prescribed while a 3D conformal technique (3D-CRT) was used for irradiation. The primary study endpoints were to assess the therapeutic impact of this schedule in terms of relapse free survival (RFS), overall survival (OS) survival and palliation of symptoms. The secondary endpoints were the evaluation of acute toxicity of the lung, esophagus and the skin. The intended followup was 3 years. The median age was 73.5 years (range 71-85). RESULTS: The median RFS was 12 months, while the median OS was 17 months. Symptoms relief was up to 20% for cough, 52.5% for haemoptysis, 40% for thoracic pain and 17.5% for dyspnoea. Acute lung toxicity in terms of radiation pneumonitis was recorded as 6/40 (15%) grade 1, 26/40 (65%) grade 2 and 8/40 (25%) grade 3. Additionally, grade 1 and 2 acute esophageal toxicity was recorded in 10/40 (25%) and 30/40 (75%) patients, respectively. Acute skin toxicity with grade 2 erythema was recorded in only 2/40 (5%) patients while most patients developed grade 1 skin erythema. Grade 3 late lung toxicity was recorded in 10/40 (25%) patients. CONCLUSIONS: This study showed that the proposed scheme has a moderate radiation-induced lung toxicity rate and an acceptable therapeutic ratio. Taking into consideration its cost effectiveness, the proposed hypofractionated scheme is a good alternative to conventional fractionation.

The impact of dose matrix and voxel dimensions to dose calculation for stereotactic radiosurgery.

PURPOSE: The purpose of the present study was the optimization of dose calculation for intracranial stereotactic radiosurgery. METHODS: We evaluated the Singular Value Decomposition (SVD) analysis as a novel optimization technique. Our approach to dose distribution optimization was to recover estimates of minibeams weights from well-defined provisional dose matrices. The dose delivered by a set of minibeams is formulated as a matrix equation. We studied the influence of dose matrix and voxel dimensions on the conditioning of stereotactic radiotherapy inverse problem. Dose matrix dimensions varied from 16 to 96 mm3, while voxel dimension was kept constant at 2 mm3. In the assessment of voxel dimension, matrix dimension was kept constant at 80 mm3 while voxel dimensions varied from 1 to 8 mm3. The reconstruction of dose distributions was studied using a truncated SVD expansion in the calculation of approximation to the generalised matrix inverse. RESULTS: The conditioning was deteriorated by either the decreasing of dose matrix dimensions or by the increasing of voxel size. The condition number was equal to 89×103 and 7×103 for the 16 mm3 and 96 mm3 dose matrix dimensions, respectively. The condition number was equal to 9.9×103 and to 2.7×106 for 1 mm3 and 8 mm3 voxel size, respectively. The reconstruction of dose distributions revealed that an ill-conditioned problem yields poor quality reconstruction. CONCLUSION: We considered that a good compromise between quality of dose distribution, time calculation and hard disk memory would be the use of a 64 mm3 matrix dimension with a 2 mm3 voxel size.

Review of the three-field techniques in breast cancer radiotherapy.

Breast cancer is often treated with radiotherapy (RT), with two opposing tangential fields. When indicated, supraclavicular lymph nodes have to be irradiated, and a third anterior field is applied. The junction region has the potential to be over or underdosed. To overcome this problem, many techniques have been proposed. A literature review of 3 Dimensional Conformal RT (3D CRT) and older 3-field techniques was carried out. Intensity Modulated RT (IMRT) techniques are also briefly discussed. Techniques are categorized, few characteristic examples are presented and a comparison is attempted. Three-field techniques can be divided in monoisocentric and two-isocentric. Two-isocentric techniques can be further divided in full field and half field techniques. Monoisocentric techniques show certain great advantages over two-isocentric techniques. However, they are not always applicable and they require extra caution as they are characterized by high dose gradient in the junction region. IMRT has been proved to give better dosimetric results. Three-field matching is a complicated procedure, with potential of over or undredosage in the junction region. Many techniques have been proposed, each with advantages and disadvantages. Among them, monoisocentric techniques, when carefully applied, are the ideal choice, provided IMRT facility is not available. Otherwise, a two-isocentric half beam technique is recommended.

In vivo dosimetry in the field junction area for 3D-conformal radiation therapy in breast and head & neck cancer cases: A quality assurance study.

PURPOSE: To investigate the accuracy of field junctioning planning techniques (monoisocentric and rotating couch technique) for 3D-conformal radiotherapy (3D-CRT). METHODS: In vivo dosimetry has been performed using thermo- luminescence dosimeters (TLDs) in 10 head and neck cancer patients (treated with monoisocentric technique) and 10 breast cancer patients (treated with rotating couch technique) irradiated with a 6 MV photon beam. Entrance dose measurements were performed in selected regions including the field junction area. RESULTS: The mean deviation between measured and expected dose in the region of junction was significantly higher in breast cases compared to head and neck irradiation (-2.8±15.4% and 0.2±8.2% respectively; Mann-Whitney U test: p=0.002). A comparison between lateral head and neck fields and tangential breast fields revealed that the latter was associated with larger dose discrepancies (-2.2 ± 4.6% vs -3.5 ± 5.7% respectively; Mann-Whitney U test: p=0.029). CONCLUSIONS: The results indicate the superiority of monoisocentric technique compared to the rotating couch technique in terms of dose delivery accuracy for treatments with field junctioning planning techniques.

A new hypofractionated schedule of weekly irradiation for basal cell carcinoma of the head and neck skin area in elderly patients.

The effectiveness of radiotherapy in patients with basal cell carcinoma (BCC) has been already reported in the literature. However, there is little information about the irradiation of BCC in elderly patients, especially due to the low conformity of them to daily irradiation. Thirty-eight retrospectively selected elderly patients (78 years as median age) diagnosed with skin BCC of the head and neck area were treated with five weekly fractions of 600 cGy by three-dimensional conformal radiotherapy (3DCRT) as an adjuvant treatment. The primary endpoint was the relapse free survival. Acute toxicity, as secondary endpoint, was assessed according to EORTC/RTOG criteria. Among our patients, there were only three local recurrences at 15, 32 and 38 months post-3DCRT. There was no severe toxicity, while only 10 out of 38 patients presented grade II/III skin toxicity. Our proposed irradiation schedule seems effective in terms of local control and acute toxicity and could be an alternative scheme for elderly patients unfit for daily irradiation.

Radiotherapy combined with daily escitalopram in patients with painful bone metastasis: clinical evaluation and quality of life measurements.

PURPOSE: To prospectively assess the efficacy of the selective serotonin inhibitor escitalopram on painful bone metastases, in combination with external beam irradiation. METHODS: Forty-three patients with cancer metastatic to bone and suffering from depression were treated with 3 Dimensional Conformal Radiotherapy (3DCRT) (30 Gy; 3 Gy/fraction, 5 days/week) combined with escitalopram (20 mg/day). Pain relief was evaluated with Wong/Baker Faces Pain Scale. The patients reported outcome using a RTOG-EORTC quality-of-life self-questionnaire (QLQ-C30 v3.0) and the status of depression according to Hamilton Scale (HAM-17). The assessment was performed at baseline and 6-8 weeks after radiotherapy. RESULTS: Patients treated with radiotherapy and escitalopram tended to show a good response to pain and improvement of their quality of life. CONCLUSIONS: Though our data concerned a rather small number of patients, addition of escitalopram to 3DCRT accomplished a high clinical benefit rate on neuropathic pain from bone metastasis.

A hypofractionated radiotherapy schedule with 57.75Gy in 21 fractions for T1-2N0 prostate carcinoma: Analysis of late toxicity and efficacy.

PURPOSE: The primary endpoint was to assess the late toxicity of a hypofractionated radiotherapy schedule in relation to radiation parameters concerning the rectum and bladder. The second endpoint was to assess a composite of biochemical and clinical failure. METHODS: Sixty-four prospectively selected patients diagnosed with localized low risk prostate cancer, Gleason score (GS) <7, PSA <10, and T1-2N0, were treated with external 3- dimensional conformal radiotherapy (3D-CRT). Patients received 57.75 Gy in 21 daily fractions of 2.75 Gy/fraction. RESULTS: Late gastrointestinal (GI) toxicity was as follows: grade 0: 47 (73.4 %) patients, grade 1: 12 (19.2 %), grade 2: 4 (6.3%), and grade 3: 1 (1.6%). There was a significant correlation between D50, V70 and EORTC/RTOG late rectal toxicity score (p<0.001 and p=0.006, respectively). Grade 1 and 2 late bladder toxicity was seen in 4.7 and 1.6% of the patients, respectively. With a median follow up of 18 months no biochemical relapse was observed. CONCLUSION: The present study supports the use of hypofractionated radiation therapy which showed a high therapeutic ratio with acceptable toxicity and no biochemical relapse during follow-up.

First treatment of mycosis fungoides by total skin electron beam (TSEB) therapy in Greece.

BACKGROUND: Mycosis fungoides (MF), the most common subtype of cutaneous T-Cell Lymphoma (CTCL), is a rare chronic skin neoplasia. Total skin electron irradiation has been employed along with a variety of other topical or systemic treatments for MF management. AIM: To report the first case treated by TSEB irradiation protocol in Greece. MATERIALS AND METHODS: A fractionated 36 Gy total skin electron beam (TSEB) therapy was prescribed to a 65-years-old male patient with mycosis fungoides (MF), stage IIB, refractory to several treatments during a 20-year period. Dose uniform delivery was monitored by thermo-luminescence dosimetry. RESULTS AND DISCUSSION: The homogeneous skin dose distribution resulted in a complete clinical response. Limited, irradiation-oriented, side effects appeared. CONCLUSIONS: The first TSEB irradiation prescription in Greek medical chronicles was proved effective in this case of tumor stage MF (T3-IIB), which had been refractory to several single or combination treatments.

The Impact of Nanomedicine on Soft Tissue Sarcoma Treated by Radiotherapy and/or Hyperthermia: A Review.

This article presents a comprehensive review of nanoparticle-assisted treatment approaches for soft tissue sarcoma (STS). STS, a heterogeneous group of mesenchymal-origin tumors with aggressive behavior and low overall survival rates, necessitates the exploration of innovative therapeutic interventions. In contrast to conventional treatments like surgery, radiotherapy (RT), hyperthermia (HT), and chemotherapy, nanomedicine offers promising advancements in STS management. This review focuses on recent research in nanoparticle applications, including their role in enhancing RT and HT efficacy through improved drug delivery systems, novel radiosensitizers, and imaging agents. Reviewing the current state of nanoparticle-assisted therapies, this paper sheds light on their potential to revolutionize soft tissue sarcoma treatment and improve patient therapy outcomes.

Single- versus Multi-computed Tomography Simulation for High-dose-rate Postoperative Gynecological Intracavitary Brachytherapy.

Introduction: This study aimed to investigate whether there is a dosimetric difference of implementing single instead of multi-computed tomography (CT) simulation treatment planning for high-dose-rate postoperative gynecological intracavitary brachytherapy (BT). Materials and Methods: Eighty patients were registered in the study. They received three BT fractions of 7 Gy/week (three CTs, three original plans). The organs at risk (OAR), the rectal wall, and the clinical target volume (CTV) were delineated. The delivered doses for the 2cc of OARs (D2cc), 1cc of rectal wall (D1cc), as well as for the 90% and 100% of CTV volume (DCTV90%, DCTV100%) were evaluated. To evaluate the values of the above parameters if the single-CT-simulation method has been chosen, the time of the first treatment plan was corrected for the decay and applied as the second and third CT, retrospectively, creating the next fractions (two revised plans). Results: No statistically significant (P > 0.05) differences were found between the original and revised plans for the OARs and CTV. However, for the single-CT-simulation method, it was noted that the dose constraints for the total rectal dose were exceeded in some cases (36.3%). Conclusion: The fact that rectal dose constraints were exceeded in 1/3 of patients with the single-CT-simulation method is dosimetrically significant.