Safer and More Convenient Modern Curative Radiotherapy for Patients With Early Prostate Cancer

BACKGROUND/AIM

New fractionation schedules with modern tools are a very rapidly developing area in curative radiotherapy (RT) for early prostate cancer (PC). To apply these techniques in everyday clinical practice, we planned this phase II trial with different fractionation schedules and followed up patients using careful health-related quality of life (QoL) questionnaires for three years.

PATIENTS AND METHODS

Seventy-three PC patients with one or two intermediate PC risk factors according to the National Comprehensive Cancer Network criteria were recruited. Forty-two patients were treated with 78/2 Gy (conventional fractionation, CF) or 60/3 Gy (moderately hypofractionation RT, MHF), and 31 patients were treated with 36.25/7.25 Gy (stereotactic body RT, SBRT). Their PSA levels were measured, and QoL data were assessed for genitourinary (GU), gastrointestinal (GI), and sexual well-being between the baseline and three years after treatment. A Rectafix™ (RF) fixation device was used in 30 patients in the CF/MHF group.

RESULTS

Three years after radiotherapy (RT), there were no differences between the groups regarding GU, GI, sexual well-being, PSA response, or clinical outcomes. On QoL questionnaires, men in the SBRT group were more satisfied with their QoL at the end of RT. Urinary symptoms (p=0.004) and urinary incontinence were more common in the CF/MHF group (p=0.016) three months after RT. The use of RF reduced GI toxicity, especially urgency (p=0.002), at three years after RT.

CONCLUSION

Modern, short, five-fraction stereotactic radiotherapy as a local curative treatment for PC is well tolerated and safe. Our novel results showing a decrease in GI toxicity using Rectafix™ fixation should be confirmed in future randomized trials.

Chemotherapy and Radiotherapy Long-Term Adverse Effects on Oral Health of Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

The survival rate for pediatric cancer has increased over the past few decades, short- and long-term complications have been detected and studied, and oral complications have emerged as an important topic of research. Here, we aimed to highlight the importance of oral manifestations that may only become apparent years or even decades after cancer treatment. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. We searched articles using PubMed via the MEDLINE, Web of Science, and LILACS databases until October 2023. Overall, 35 observational studies were included, and the results estimated a pooled prevalence of the following dental anomalies: discoloration, 53%; crown-root malformations and agenesis, 36%; enamel hypoplasia, 32%; root development alterations, 29%; unerupted teeth, 24%; microdontia, 16%; hypodontia, 13%; and macrodontia, 7%. Most childhood cancer survivors have at least one dental sequela. Childhood cancer survivors presented a higher risk of having dental alterations than control counterparts. Additional analyses reveal possible sex-based differences that should be explored in future studies. These results collectively highlight the importance of oral healthcare and the prevention of disease in childhood cancer survivors.

Re-Irradiation for Head and Neck Cancer: Cumulative Dose to Organs at Risk and Late Side Effects

Simple Summary

Local recurrences of head and neck cancer are unfortunately common and can be difficult to treat. The treatment is challenging, partly due to the location, with several important organs in the head and neck area, but also because recurrence often occurs in an area already treated with radiotherapy. It has been shown that repeat radiotherapy, re-irradiation, can offer long-lasting tumor control and sometimes even cure in selected patients. However, there is a risk of normal tissue close to the tumor being damaged by high cumulative doses of radiotherapy. In this study, we aim to establish levels of cumulative dose to specific organs that could be considered reasonably safe to deliver at re-irradiation without causing high rates of severe side effects. Increased knowledge in dose–response relationships in re-irradiation for head and neck cancer will facilitate a tailored treatment for the individual patient.

Abstract

Re-irradiation in head and neck cancer is challenging, and cumulative dose constraints and dose/volume data are scarce. In this study, we present dose/volume data for patients re-irradiated for head and neck cancer and explore the correlations of cumulative dose to organs at risk and severe side effects. We analyzed 54 patients re-irradiated for head and neck cancer between 2011 and 2017. Organs at risk were delineated and dose/volume data were collected from cumulative treatment plans of all included patients. Receiver–operator characteristics (ROC) analysis assessed the association between dose/volume parameters and the risk of toxicity. The ROC-curve for a logistic model of carotid blowout vs. maximum doses to the carotid arteries showed AUC = 0.92 (95% CI 0.83 to 1.00) and a cut-off value of 119 Gy (sensitivity 1.00/specificity 0.89). The near-maximum dose to bones showed an association with the risk of osteoradionecrosis: AUC = 0.74 (95% CI 0.52 to 0.95) and a cut-off value of 119 Gy (sensitivity 1.00/specificity 0.52). Our analysis showed an association between cumulative dose to organs at risk and the risk of developing osteoradionecrosis and carotid blowout, and our results support the existing dose constraint for the carotid arteries of 120 Gy. The confirmation of these dose–response relationships will contribute to further improvements of re-irradiation strategies.

Late Side Effects in Normal Mouse Brain Tissue After Proton Irradiation

Radiation-induced late side effects such as cognitive decline and normal tissue complications can severely affect quality of life and outcome in long-term survivors of brain tumors. Proton therapy offers a favorable depth-dose deposition with the potential to spare tumor-surrounding normal tissue, thus potentially reducing such side effects. In this study, we describe a preclinical model to reveal underlying biological mechanisms caused by precise high-dose proton irradiation of a brain subvolume. We studied the dose- and time-dependent radiation response of mouse brain tissue, using a high-precision image-guided proton irradiation setup for small animals established at the University Proton Therapy Dresden (UPTD). The right hippocampal area of ten C57BL/6 and ten C3H/He mice was irradiated. Both strains contained four groups (n_irradiated = 3, n_control = 1) treated with increasing doses (0 Gy, 45 Gy, 65 Gy or 85 Gy and 0 Gy, 40 Gy, 60 Gy or 80 Gy, respectively). Follow-up examinations were performed for up to six months, including longitudinal monitoring of general health status and regular contrast-enhanced magnetic resonance imaging (MRI) of mouse brains. These findings were related to comprehensive histological analysis. In all mice of the highest dose group, first symptoms of blood-brain barrier (BBB) damage appeared one week after irradiation, while a dose-dependent delay in onset was observed for lower doses. MRI contrast agent leakage occurred in the irradiated brain areas and was progressive in the higher dose groups. Mouse health status and survival corresponded to the extent of contrast agent leakage. Histological analysis revealed tissue changes such as vessel abnormalities, gliosis, and granule cell dispersion, which also partly affected the non-irradiated contralateral hippocampus in the higher dose groups. All observed effects depended strongly on the prescribed radiation dose and the outcome, i.e. survival, image changes, and tissue alterations, were very consistent within an experimental dose cohort. The derived dose–response model will determine endpoint-specific dose levels for future experiments and may support generating clinical hypotheses on brain toxicity after proton therapy.

Female sexual problems after treatment for colorectal cancer - a population-based study

AIM

There has been limited focus on female sexuality after treatment for colorectal cancer. The aim of this study was to investigate long-term female sexual dysfunction in disease-free colorectal cancer survivors in the Danish population.

METHOD

All female Danish patients treated for colorectal cancer between 2001 and 2014 were included if they reported to have been sexually active at the time of diagnosis. They were requested to answer the validated Sexual Vaginal Changes Questionnaire.

RESULTS

A total of 2402 patients were included for analysis (43%). Overall, rectal cancer patients reported more sexual inactivity and problems compared to colon cancer patients, but there were no differences in any sexual function domains when excluding irradiated patients and patients with a permanent stoma. A permanent stoma was associated with sexual inactivity [OR 2.56 (95% CI 1.42-4.70)] and overall sexual dysfunction [OR 2.95 (95% CI 1.05-6.38)] in colon cancer patients, as well as inactivity [OR 1.43 (95% CI 1.01-2.04)] and overall dysfunction [OR 2.0 (95% CI 1.18-3.41)] in rectal cancer patients. Furthermore, a permanent stoma was associated with dyspareunia [OR 2.17 (95% CI 1.39-3.38)] and reduced vaginal dimension [OR 3.16 (95% CI 1.99-5.01)]. In rectal cancer patients, radiotherapy exposure increased the odds for overall sexual dysfunction [OR 1.80 (95% CI 1.02-3.16)] and was associated with dyspareunia [OR 1.72 (95% CI 0.95-3.12)].

CONCLUSION

Sexual problems after treatment of colorectal cancer are common. Major risk factors are a permanent stoma and radiotherapy. Relevant patients should be offered professional counselling and treatment.

The Efficacy and Late Toxicities of Computed Tomography-based Brachytherapy with Intracavitary and Interstitial Technique in Advanced Cervical Cancer

Purpose: To report the efficacy and late side effects(LSEs) of CT-based image-guided brachytherapy for the treatment of cervical cancer.

Materials: Between 2008 and 2014, 100 patients with FIGO stage IIB-IVA cervical carcinoma were analyzed. The patients received pelvic irradiation (45-50 Gy in 25 fractions) with concurrent chemotherapy, whereas the mean prescribed EBRT dose, including initial and boost doses to positive lymph nodes, ranged from 54 to 64 Gy. Afterwards, intracavitary(IC) or combined intracavitary/interstitial(IC/IS) brachytherapy was performed using a CT-based procedure with prescribed doses of 6 or 8 Gy in 3-7 fractions.

Results: The median follow-up time was 46 months. The 5-year local control, distant metastasis-free survival, and overall survival rates were 88.9%, 81.8%, 77.9%, respectively. IC/IS brachytherapy improved the HR-CTV D90 compared with IC (p<0.01). Seven patients (7.0%) had grade 2 bladder LSEs and none had grade 3/4 bladder LSEs. There was no significant relationship between bladder LSEs and the dose-volume histogram (p>0.05 for all). Thirty-seven patients (37%) had grade 2 rectal LSEs, 3(3%) had grade 3 rectal LSE. The rectum D_1cc, D_2cc, and D_5cc values were significantly higher in patients with grades 2/3 rectal toxicity than in those with grades 0/1 (p<0.05 for all). There was no grade 2 and above small bowel LSEs.

Conclusions: CT-based brachytherapy planning can achieve excellent local control with acceptable morbidity. HR-CTV D90 can increase in the IC/IS group compared with the IC group. The D_1cc, D_2cc, and D_5cc all showed excellent predictive values for rectal LSEs.

Late rectal toxicity determined by dose-volume parameters in computed tomography-based brachytherapy for locally advanced cervical cancer

The aim of this study was to observe the relationship between dose–volume histogram (DVH) parameters and rectal late side effects (LSE) in computed tomography (CT)‐based brachytherapy (BT) for patients with locally advanced cervical cancer. In total, 144 cervical cancer patients received external beam radiotherapy and CT‐based BT. The data from 111 survival cases with pelvic local control (LC) were used to analyze the relationship between DVH parameters and rectal LSE. The total doses, manifesting 2, 1, and 0.1 cm³ (D_2cc, D_1cc, and D_0.1cc) of the rectum, and D₉₀ for high‐risk clinical target volume (HR CTV) were computed and normalized to 2 Gy fractions (EQD2) using a linear‐quadratic model. The rectal LSE were evaluated by the late effects in normal tissues‐subjective, objective, management, and analytic (LENT‐SOMA) scale. A dose–response relationship was evaluated by probit analyses. For all patients, the total rate of rectal LSE was 56%, and the rate of ≥Grade 2 LSE was 27.4%. For the 111 survival cases with pelvic LC, the total mean for D_2cc was 71.23 ± 5.54 Gy for the rectum, and the D_2cc, D_1cc, and D_0.1cc values for Grades 2 and 3 were higher than those for Grades 0 and 1. In addition, the number of complications increased, and the complications became more severe as the dose increased, with a dose of 73.5 Gy resulting in a 10% probability of ≥Grade 3 LSE. In conclusion, DVH parameters could predict the incidence and grades of rectal LSE in CT‐based BT. D_2cc showed an excellent predictive value, and 73.5 Gy for D_2cc of the rectum might be considered as an alternative dose limit.

Genetic polymorphisms in DNA repair and damage response genes and late normal tissue complications of radiotherapy for breast cancer

Breast-conserving surgery followed by radiotherapy is effective in reducing recurrence; however, telangiectasia and fibrosis can occur as late skin side effects. As radiotherapy acts through producing DNA damage, we investigated whether genetic variation in DNA repair and damage response confers increased susceptibility to develop late normal skin complications. Breast cancer patients who received radiotherapy after breast-conserving surgery were examined for late complications of radiotherapy after a median follow-up time of 51 months. Polymorphisms in genes involved in DNA repair (APEX1, XRCC1, XRCC2, XRCC3, XPD) and damage response (TP53, P21) were determined. Associations between telangiectasia and genotypes were assessed among 409 patients, using multivariate logistic regression. A total of 131 patients presented with telangiectasia and 28 patients with fibrosis. Patients with variant TP53 genotypes either for the Arg72Pro or the PIN3 polymorphism were at increased risk of telangiectasia. The odds ratios (OR) were 1.66 (95% confidence interval (CI): 1.02-2.72) for 72Pro carriers and 1.95 (95% CI: 1.13-3.35) for PIN3 A2 allele carriers compared with non-carriers. The TP53 haplotype containing both variant alleles was associated with almost a two-fold increase in risk (OR 1.97, 95% CI: 1.11-3.52) for telangiectasia. Variants in the TP53 gene may therefore modify the risk of late skin toxicity after radiotherapy.