History of the development of radiotherapy in Latin America

The effect of photobiomodulation on the radiosensitivity of cancer cells: a literature review

The goal of radiotherapy (RT) in cancer treatment is to destroy tumor tissue while preserving nearby healthy tissue. However, RT often causes adverse effects that significantly impact patients' quality of life. Tumor cells, which have high proliferation rates, are susceptible to radiation, especially during the G2 and mitosis phases of the cell cycle. Numerous studies have explored ways to enhance the Radiosensitivity of tumors to make RT more effective while minimizing harm to healthy cells. This review examines the potential use of photobiomodulation (PBM) as a radiosensitizer for cancer cells to improve the effectiveness and safety of radiotherapy. A literature search was conducted in the MEDLINE/PubMed and Google Scholar databases using keywords like "PBM, low-level light therapy, cancer cells, tumor cells, radiosensitizer, and ionizing radiation." Studies meeting the inclusion criteria were reviewed and analyzed. Several studies investigated PBM as a radiosensitizer for various cancer cell lines, including HeLa, HeLa Kyoto, A431, SCC9, and Cal 27. Most of these studies found that pre-exposure of cancer cells to PBM improved the effectiveness of radiation in destroying tumor cells. PBM is a promising, affordable, and noninvasive technique that could improve cancer treatment outcomes by increasing tumor sensitivity to radiation and reducing side effects. However, more research is needed to thoroughly assess the benefits of combining PBM with RT. Clinical trial number: not applicable. Clinical trial number: not applicable.

Current availability of radiotherapy devices in Peru and artificial intelligence-based analysis for constructing a nationwide implementation plan

PURPOSE

We provide for the first time a comprehensive situational diagnosis and propose an artificial intelligence (AI)-assisted nationwide plan of implementation, attending the most urgent needs.

METHODS

Baseline information was collected from open-source databases of the Peruvian Government. Data on cancer incidence from the Health Authorities and GLOBOCAN were collected and compared. The existing external-beam radiotherapy (EBRT) devices and brachytherapy (BT) units were identified and information on their obsolescence was additionally collected. The ten most common cancer entities with RT indication were considered for the analysis. Utilizing open-source softwares, population clusters based on density, cancer incidence, geographic distribution, existing facilities able to be implemented with radiotherapy and travel times for patients were defined. A coding for identifying the best possible locations with AI was developed, keeping the allocation of resources to the minimum possible. A projection until 2030 on required resources was additionally elaborated.

RESULTS

As of 2023 eight additional EBRT and seven BT devices were needed to cover the existing demand. The artificial-intelligence algorithm yielded the regions where these resources should be primarily allocated. An increase in demand of approximately 22% is expected until 2030, which translates into additional 23 EBRT and 16 BT devices, considering the replacement of obsolete units until then.

CONCLUSION

Increased investment pace is required to cover the existing RT demand in Peru. This AI-assisted analysis might help prioritize allocation of resources. The code employed in this work will be made publicly available, so this method could be replicated in other developing economies.

First-Line (1L) Treatment Decision Patterns and Survival of Hormone Receptor (HR)-Positive/HER2-Negative Advanced Breast Cancer (ABC) Patients in a Latin American (LATAM) Public Institution

Advanced breast cancer is an incurable disease, with a median overall survival of 3 years, including in countries without access problems. Although chemotherapy is reserved in some cases, it is still used in many countries as a first-line therapy. The aim of our study is to evaluate the first-line treatment choices and the factors that influence therapeutic decisions. A retrospective analysis was conducted of hormone receptor (+)/HER2 (-) advanced breast cancer patients classified into three groups according to the first-line and second-line treatment received: endocrine therapy-chemotherapy, endocrine therapy-endocrine therapy and chemotherapy-endocrine therapy. Additionally, we explored the overall survival of sequencing therapy groups. First-line chemotherapy was chosen in 34% of patients. Also, around 60% of our patients met the "aggressive disease" criteria from the RIGHT Choice trial, justifying the use of chemotherapy in a population with poor prognosis. Furthermore, de novo and progressive disease were prognostic factors that influenced the use of chemotherapy as a first-line treatment. Regarding overall survival, the sequencing treatment groups in this trial saw an increase in survival compared with patients of the MONALEESA trials (endocrine therapy alone arms). No significant differences in progression-free survival or overall survival were found in the treatment sequencing groups. There was a higher use of chemotherapy as a first-line therapy, with de novo and "aggressive disease" criteria being the main factors to influence the decision.

Developing an educational "hub": impact of a distance-learning curriculum in a multinational cohort

PURPOSE

To address a gap in radiation oncology education in low- and middle-income countries (LMICs), we sought to evaluate the effectiveness and generalizability of a refined curriculum on intensity modulated radiotherapy (IMRT) offered to existing radiation therapy (RT) clinics across Africa and Latin America (LATAM) at no cost.

METHODS

A curriculum was created based on prior needs assessments and adapted for participating medical physicists, radiation oncologists, radiation therapists, and trainees in LMICs. English-speaking and Spanish-speaking teams of volunteer educators delivered 27 hour-long sessions 1-2 times weekly for 4 months using video conferencing to African and LATAM cohorts, respectively. Pre- and post-course multiple-choice examinations were administered to LATAM participants, and pre- and post-course self-confidence (1-5 Likert-scale) and open-ended feedback were collected from all participants.

RESULTS

Twenty-five centers across Africa (13) and LATAM (12) participated, yielding a total of 332 enrolled participants (128 African, 204 LATAM). Sessions were delivered with a mean of 44 (22.5) and 85 (25.4) participants in the African and LATAM programs, respectively. Paired pre and post-course data demonstrated significant (p < 0.001) improvement in knowledge from 47.9 to 89.6% and self-confidence across four domains including foundations (+ 1.1), commissioning (+ 1.3), contouring (+ 1.7), and treatment planning (+ 1.0). Attendance was a significant predictor of change in self-confidence in "high attendance" participants only, suggesting a threshold effect. Qualitative data demonstrates that participants look forward to applying their knowledge in the clinical setting.

CONCLUSION

A specialized radiation oncology curriculum adapted for LMIC audiences was effective for both African and LATAM participants. Participant feedback suggests that the refined IMRT course empowered clinics with knowledge and confidence to help train others. This feasible "Hub and Spokes" approach in which a distance-learning course establishes a hub to be leveraged by spokes (learners) may be generalizable to others aiming to reduce global health care disparities through training efforts.

Early repeat resection for residual glioblastoma: decision-making among an international cohort of neurosurgeons

OBJECTIVE

The importance of extent of resection (EOR) in glioblastoma (GBM) has been thoroughly demonstrated. However, few studies have explored the practices and benefits of early repeat resection (ERR) when residual tumor deemed resectable is unintentionally left after an initial resection, and the survival benefit of ERR is still unknown. Herein, the authors aimed to internationally survey current practices regarding ERR and to analyze differences based on geographic location and practice setting.

METHODS

The authors distributed a survey to the American Association of Neurological Surgeons and Congress of Neurological Surgeons Tumor Section, Society of British Neurological Surgeons, European Association of Neurosurgical Society, and Latin American Federation of Neurosurgical Societies. Neurosurgeons responded to questions about their training, practice setting, and current ERR practices. They also reported the EOR threshold below which they would pursue ERR and their likelihood of performing ERR using a Likert scale of 1-5 (5 being the most likely) in two sets of 5 cases, the first set for a patient's initial hospitalization and the second for a referred patient who had undergone resection elsewhere. The resection likelihood index for each respondent was calculated as the mean Likert score across all cases.

RESULTS

Overall, 180 neurosurgeons from 25 countries responded to the survey. Neurosurgeons performed ERRs very rarely in their practices (< 1% of all GBM cases), with an EOR threshold of 80.2% (75%-95%). When presented with 10 cases, the case context (initial hospitalization vs referred patient) did not significantly change the surgeon ERR likelihood, although ERR likelihood did vary significantly on the basis of tumor location (p < 0.0001). Latin American neurosurgeons were more likely to pursue ERR in the provided cases. Neurosurgeons were more likely to pursue ERR when the tumor was MGMT methylated versus unmethylated, with a resection likelihood index of 3.78 and 3.21, respectively (p = 0.004); however, there was no significant difference between IDH mutant and IDH wild-type tumors.

CONCLUSIONS

Results of this survey reveal current practices regarding ERR, but they also demonstrate the variability in how neurosurgeons approach ERR. Standardized guidelines based on future studies incorporating tumor molecular characteristics are needed to guide neurosurgeons in their decision-making on this complicated issue.

The state of gynecologic radiation therapy in low- and middle-income countries

A disproportionate burden of gynecologic malignancies occurs in low- and middle-income countries. Radiation therapy is an integral component of treatment for gynecologic malignancies both from a curative (locally advanced cervical cancer) and palliative (bleeding cervical or pelvic mass) standpoint. Critical to understanding how better to serve patients in this regard is understanding both the extent of disease epidemiology and the radiotherapy infrastructure to treat these diseases. In this review, we explore various geographic regions and how they address a unique set of challenges specific to the peoples and culture of the region. We identify common threads across regions, including sparse distribution of radiation equipment, geographic access, and specialized training. We also highlight examples of success in the use of telemedicine and cross-cultural partnerships to help bolster access to training to ensure increased access to adequate and appropriate treatment of gynecologic malignancies.

Evaluation of mesalazine polymeric conjugate in the treatment of actinic proctitis in rats

Purpose:

The present study aimed at testing a new formulation of mesalazine linked to chondroitin sulfate and its components alone in the treatment of actinic proctitis in rats.

Methods:

Forty-seven female Wistar rats were submitted to pelvic radiation and divided into eight groups: control A, mesalazine A, chondroitin A, and conjugate A, gavage of the according substance two weeks after irradiation and sacrifice three weeks after oral treatment; control C, mesalazine C, chondroitin C, and conjugate C, sacrifice six weeks after oral treatment. The rectum was submitted to histological characterization for each of the findings: inflammatory infiltrate, epithelial degeneration, mucosal necrosis, and fibrosis.

Results:

The inflammatory infiltrate was more intense in chondroitin A, mesalazine A, and conjugate C. The collagen deposition was less intense in chondroitin A, and mesalazine A, and more intense in control C.

Conclusions:

Mesalazine and chondroitin alone were efficacious in inducing a delayed inflammatory response, hence reducing the late fibrosis. The conjugate was able to induce an ever more delayed inflammatory response.

COVID's Impact on Radiation Oncology: A Latin American Survey Study

PURPOSE

The impact of the COVID-19 pandemic on Latin American radiation therapy services has not yet been widely assessed. In comparison to centers in Europe or the United States, the scarcity of data on these terms might impair design of adequate measures to ameliorate the pandemic's potential damage. The first survey-based analysis revealing regional information is herein presented.

METHODS AND MATERIALS

From May 6 to May 30, 2020, the American Society for Radiation Oncology's COVID-19 Survey was distributed across Latin America with support of the local national radiation therapy societies. Twenty-six items, including facility demographic and financial characteristics, personnel and patient features, current and expected impact of the pandemic, and research perspectives, were included in the questionnaire.

RESULTS

Complete responses were obtained from 115 (50%) of 229 practices across 15 countries. Only 2.6% of centers closed during the pandemic. A median of 4 radiation oncologists (1-27) and 9 (1-100) radiation therapists were reported per center. The median number of new patients treated in 2019 was 600 (24-6200). A median 8% (1%-90%) decrease in patient volume was reported, with a median of 53 patients (1-490) remaining under treatment. Estimated revenue reduction was 20% or more in 53% of cases. Shortage of personal protective equipment was reported in 51.3% of centers, and 27% reported personnel shortage due to COVID-19. Reported delays in treatment for low-risk entities included early stage breast cancer (42.6%), low-risk status prostate cancer (67%), and nonmalignant conditions (42.6%). Treatment of COVID-19 patients at designated treatment times and differentiated bunkers were reported in 22.6% and 10.4% of centers, respectively. Telehealth initiatives have been started in 64.3% of facilities to date for on-treatment (29.6%) and posttreatment (34.8%) patients.

CONCLUSIONS

Regional information regarding COVID-19 pandemic in Latin America may help elucidate suitable intervention strategies for personnel and patients. Follow-up surveys will be performed to provide dynamic monitoring the pandemic's impact on radiation therapy services and adoption of ameliorating measures.

Impact of a SBRT/SRS longitudinal telehealth training pilot course in Latin America

PURPOSE

To assess the impact of longitudinal telehealth training in stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) for clinicians in Latin America.

MATERIALS AND METHODS

Professionals from two Peruvian centers received an initial SBRT/SRS on-site training course and subsequently received follow-up telehealth training (interventional group) or not (negative control arm). Twelve live video conference sessions were scheduled. Surveys pre- and post-curriculum measured participants' confidence in seven practical domains of SBRT/SRS, based on Likert scales of 1-5, and post-curriculum surveys assessed educators' experiences.

RESULTS

Sixty-one participants were registered, with an average of 24 attendees per session. Pre- and post- surveys were completed by 22 participants. For interventional and negative-control groups, mean changes in Likert scale were satisfactory for the former and remained unmodified for the latter.

CONCLUSIONS

Conducting telehealth educational programs via virtual classroom sessions could be a reliable method to augment training for SBRT and SRS.

Present status of Medical Physics practice in Mexico: An occupational analysis

PURPOSE

To present an overview of the status of Medical Physics practice in Mexico, promote the legal recognition of Medical Physics high-end training, and provide information that will potentially improve the Mexican healthcare system.

METHODS

For the purpose of this research, the concept of "Medical Physics Professional/s" (MPP) is introduced to refer to any person/s executing the role of a clinical medical physicist (cMP) in whole or in part independent of academic profile, training or experience. A database of MPP in Mexico was built from official sources and personal communication with peers. Database records included the following fields: employer/s, specialty, academic profile, and annual income (when available).

RESULTS

133 centers in Mexico employ MPP, 49% of which are public institutions. 360 positions involving cMP roles were identified at the National Healthcare System (occupied by 283 MPP), 77% of which corresponded to radiation therapy. Public healthcare services hold 65% of the reported positions. Only 40% of MPP hold a graduate degree in Medical Physics, 46% of whom were located in the most densely populated region of Mexico. Of all MPP, 32% were women.

CONCLUSIONS

This work allowed to clearly identify the current challenges of Medical Physics practice in Mexico, such as: insufficiency and uneven geographical distribution of qualified manpower, gender imparity, multishifting and wage gap. The products derived from this work could be used to guide the efforts to improve the Mexican healthcare system.

Barriers in Latin America for the management of locally advanced breast cancer

Breast cancer (BC) is a highly prevalent malignancy in Latin American women, most cases being diagnosed at locally advanced or metastatic stages when options for cancer care are limited. Despite its label as a public health problem in the region, Latin American BC patients face several barriers in accessing standard of care treatment when compared with patients from developed countries. In this review, we analyse the landscape of the four main identified barriers in the region: i) high burden of locally advanced/advanced BC; ii) inadequate access to medical resources; iii) deficient access to specialised cancer care and iv) insufficient BC research in Latin America. Unfortunately, these barriers represent the main factors associated with the BC poor outcomes seen in the region. Targeted actions should be conducted independently by each country and as a region to overcome these limitations and create an enhanced model of BC care.

Advancing clinical research globally: Cervical cancer research network from Mexico

Cervical cancer is the fourth most common cancer in women with 85% of the mortality burden occurring in less-developed regions of the world. The Cervix Cancer Research Network (CCRN) was founded by the Gynecologic Cancer InterGroup (GCIG) with a mission to improve outcomes in cervix cancer by increasing access to high-quality clinical trials worldwide, with particular attention to less-developed, underrepresented sites. The CCRN held its second international educational symposium in Mexico City with ninety participants from fifteen Latin America countries in January 2017. The purpose of this symposium was to advance knowledge in cervix cancer therapy, promote recruitment to CCRN clinical trials, and to identify relevant future CCRN clinical trial concepts that could improve global care standards for women with cervical cancer.

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Cervix cancer is the fourth most common cancer in women worldwide with up to an 18-fold disparity in mortality rates.

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The Cervix Cancer Research Network (CCRN) aims to increase access to clinical trials in order to improve outcomes for women.

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The 2nd CCRN international symposium was held in Mexico City including 90 participants from 15 Latin American countries.

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CCRN clinical trials were discussed, including new trials proposed of hypofractionation and HPV targeted therapy.