Clinical application of time factor principles in radiotherapy in compensation of radiation series interruptions

BACKGROUND

The time factor plays a key role in radiotherapy. The radiotherapy overall treatment time is one of the most important predictive factors in the treatment effectiveness and is associated with better local control and impact on the overall survival. The length of the time from the dia-gnosis to radical radiotherapy or from surgery to adjuvant radiotherapy or the use of alternative fractionation schemes shortening the total treatment time also play an important role. The prevention of prolongation of the radiation series remains a fundamental and well feasible way of applying the time factor in radiotherapy.

PURPOSE

Interruption of radiotherapy usually occurs for technical reasons, due to factors at the patients side or for personnel reasons of the department. Standard procedures for the compensation for treatment breaks are part of the treatment protocols at radiotherapy departments. Possible risks of the discontinuation of radiotherapy are considered on the basis of the type and extent of the disease, the treatment intent and the condition of the patient, and the need of compensation for a break in the treatment is set. Patients are classified into three categories according to the above mentioned parameters. Compensation for the pause in radiotherapy is performed by calculating the equivalent dose in 2 Gy per fraction (EQD2); the preferred method of compensation is the one which enables observation of the planned total time of radiotherapy without extension. The benefit of local tumor control and the risk of increased acute or especially late toxicity should always be considered. In the current epidemiological situation, radiotherapy is often discontinued for COVID-19, and due to longer breaks in the treatment, it is necessary to combine multiple compensation methods in one patient.

Radiotherapy and radiosensitivity syndromes in DNA repair gene mutations

BACKGROUND

Ionizing radiation DNA damage is the main mechanism of radiotherapy (RT) action and the outcome of treatment and healthy tissue toxicity is influenced by a number of external and internal factors, including mutations in DNA damage recognition and repair. Disorders of DNA repair may result in increased sensitivity to cancer treatment.

PURPOSE

The mechanism of DNA repair and an overview of genetic syndromes with mutations in genes involved in DNA repair clarify the accelerated carcinogenesis and increased radiosensitivity in RT cancers. Most radiosensitivity syndromes are autosomal recessively inherited; examples are ataxia teleangiectasia, Nijmegen breakage syndrome, xeroderma pigmentosum, Cockayne syndrome, Bloom syndrome and Werner syndrome.

CONCLUSION

Radiotherapy is contraindicated in most homozygous patients with recessive radiosensitivity syndromes. Asymptomatic heterozygotes may have an increased risk of tumor incidence and a small part of them slightly increased risk of RT intolerance; however, this does not limit RT treatment. The high risk of secondary malignancies after radiotherapy is a contraindication to adjuvant RT in Li-Fraumeni syndrome.

Haematotoxicity in IMRT/VMAT curatively treated anal cancer

INTRODUCTION

Curative chemoradiotherapy of squamous cell carcinoma achieves long-term complete remissions in most patients and minimizing treatment toxicity becomes crucial issue. The aim of the retrospective analysis was to determine an acceptable dose to the bone marrow for radiotherapy planning not leading to increased haematological toxicity.

PATIENTS AND METHODS

In the period 2013-2019, 40 patients with squamous cell carcinoma were curatively treated at the Department of Oncology of the University Hospital Motol using intensity modulated radiotherapy (IMRT) /volumetric modulated arc radiotherapy (VMAT) technique. Women make up 90% of the group, the average age at the time of dia-gnosis was 65 years (47-81). Chemotherapy mitomycin C and 5-fluorouracil was given to 68% of patients. The bone marrow was contoured in the Varian Eclipse planning system, version 15.6.

RESULTS

Acute hematotoxicity (G3, 4, 5 according to Common Terminology Criteria for Adverse Events - CTCAE) was significantly associated with the concomitant chemoradiotherapy (P = 0.002) and the average dose to the bone marrow 27 Gy (P = 0.011). Late haematological toxicity was mild (maximum grade 1), asymptomatic, and no dependence of late haematotoxicity on any risk factor (age, gender, WHO performance status, bone marrow dose, CHT, BMI, smoking, stage) was proved. The overall survival at 5 years was 100% in stage I, 83% in stage II, 61% in stage III and 0% in stage IV. Local control at 5 years is 100% in stage I, 92% in stage II, 87% in stage III and 0% in stage IV. Local recurrence developed in 5% of radically treated patients. Distant metastases occurred in 8% of radically treated patients. Local recurrences or metastases occurred only during the first 2 years after the treatment.

CONCLUSION

Radical chemoradiotherapy in the treatment of squamous cell anal carcinoma is highly effective. IMRT/VMAT enabled to apply a sufficiently effective dose to the tumor and elective areas and reduced not only acute skin, GI and GU toxicity, but also acute haematological toxicity in cases with the dose Dmean to bone marrow lower than 27 Gy. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical, papers.

Preoperative radiotherapy for locally advanced rectal cancer and prognostic factors influencing outcome

The aim of presented study was to evaluate the impact of different factors on survival, local recurrence and development of metastatic disease in patients with rectal cancer treated with preoperative radiotherapy or 5-fluorouracil (5-FU) based concurrent chemoradiation. Retrospective clinical evaluation was performed in 165 patients (33% women and 67% men) with locally advanced rectal adenocarcinoma treated with preoperative radiotherapy or chemoradiotherapy in the period January 1998 - March 2003. Tumor extent was evaluated by CT and/or MRI and/or TRUS examination and tumor biopsy was performed during colonoscopy. The median follow up is 21 month. All patients received preoperative external beam radiation to primary tumor, adjacent lymphnodes and presacral region. Computed tomography localisation of target volume was used for 3D radiotherapy treatment planning. Accelerated short term regimen (25 Gy/5 fraction/1 week) was performed in 14% of patients especially in year 1998-2000 and normofractionated regimen (40-50 Gy/20-25 fractions/4-5 weeks) was performed in 86% of patients. Chemoradiotherapy with 5-FU was carried out in 22% of patients. Radical resection underwent 85% of patients, inoperable tumor persisted in 7% and distant metastases were detected peroperatively in 8%. The 2-year overall survival (OS) was 84% and 5-year OS was 60% following radical resection. The important prognostic factors affecting survival were postradiotherapy determined pathological staging (p=0.005), postradiotherapy tumor grade (p<0.001) and the presence of angioinvasion and/or perineural spread (p=0.023). Prognostic factors for disease-free survival were identical with those for OS. Higher local recurrence rate was associated in preradiotherapy tumor staged T4 (p=0.048) and in presence of angioinvasion and/or perineural spread (0.049). Age, tumor location, histological grade before radiotherapy and tumor downstaging were not statistically significant for survival and/or for local recurrence rate. The best survival rates were obtained in patients with postradiotherapy grade 1 tumors (5-years survival 100%), tumors without angioinvasion and perineural spread (5-years survival 65%) and in patients who obtained complete remission after preoperative radiotherapy (5-years survival 86%).

Stereotactic Radiotherapy Plus Nivolumab in Patients with Locally Advanced Pancreatic Cancer: Results from Phase 1/2 Clinical CA209-9KH Trial

INTRODUCTION

The dismal prognosis of pancreatic ductal adenocarcinoma (PDAC) highlights the urgent need for novel therapeutic strategies. Immune checkpoint inhibitors (ICIs) seem to be ineffective in most PDAC studies. Therefore, we conducted an open-label, multicenter phase 1/2 study (CA209-9KH) to evaluate the safety of stereotactic radiotherapy (SRT) and sequential ICI therapy in PDAC, as well as to validate the efficacy of this regimen as a potential activator of antitumor immunity.

METHODS

Patients aged ≥ 18 years with unresectable non-metastatic PDAC following four FOLFIRINOX induction cycles were included. Treatment comprised SRT (4 × 8 Gy) and sequential nivolumab administration until disease progression or unacceptable toxicity. The primary endpoints were safety and toxicity assessment. Secondary endpoints included progression-free survival (PFS), overall survival (OS), biomarker evaluation, and quality of life (QoL) analysis.

RESULTS

Twenty-two patients were screened, with 15 enrolled. Eleven (median) nivolumab cycles were administered. SRT demonstrated low and clinically nonsignificant toxicity, whereas nivolumab toxicity aligned with prior safety profiles, without grade 4-5 events observed. Three patients discontinued therapy owing to toxicity. Median PFS and OS were 8.1 and 13.0 months, respectively, with 12-month PFS and OS rates of 0% and 66.7%, respectively, and a 24-month OS rate of 8.9%. Biomarker levels correlated with clinical or radiological disease control. Patient-reported QoL remained acceptable, deteriorating with disease progression.

CONCLUSION

SRT and nivolumab therapy exhibited manageable toxicity profiles consistent with previous findings; however, long-term treatment responses were not achieved with this regimen in locally advanced PDAC. Another strategy to trigger antitumor immunity in PDAC needs to be sought.

TRIAL REGISTRATION

EudraCT: 2017-003404-52; ClinicalTrials.gov: NCT04098432.

New approaches in palliative systemic therapy of anal squamous cell carcinoma

BACKGROUND

Metastatic and locally recurrent inoperable anal squamous cell carcinoma (ASCC) belong to rare tumours - ASCC accounts for about 2% of gastrointestinal tumours. Synchronous metastatic involvement is usually confirmed in approximately 15% of patients and about 20 % of patients develop relapse in the form of distant metastases after curative treatment. The current standard palliative systemic treatment is a PF regimen composed of 5-fluorouracil (5-FU) with cisplatin (cDDP) or a combination of carboplatin with paclitaxel.

PURPOSE

The aim of this study is to summarize other options for systemic palliative care in ASCC, including the results of relevant clinical trials performed with new or modified regimens. Triple combinations with taxanes have yielded promising treatment results, and in particular, the inclusion of the DCF regimen (cDDP + 5-FU + docetaxel) in first-line treatment results in a significant increase in treatment responses with good treatment tolerance. Another promising option for palliative care is immunotherapy with checkpoint inhibitors PD-1 or PD-L1, which can be successfully used in palliative systemic treatment or in curative regimens. Epidermal growth factor receptor inhibitors remain the subject of research, whose role in the primary or palliative treatment of ASCC is not entirely clear.

CONCLUSION

Compared to standard chemotherapy, available data confirm the treatment outcomes improvement in the use of triple combination DCF with docetaxel or immunotherapy with checkpoint inhibitors in the treatment of metastatic ASCC.

Interstitial HDR brachytherapy for anal cancer-results and quality of life

PURPOSE

While anal cancer is a very rare oncological diagnosis representing less than 2% of lower gastrointestinal tract cancers, the incidence has doubled in the past 20 years. Radical radiochemotherapy with sequential or simultaneous boost is now the standard treatment modality. Interstitial HDR brachytherapy is one of the boost application options. Implementation of new radiotherapy techniques has resulted in improved therapeutic outcomes; however, it is still associated with acute and especially late toxicity. Gastrointestinal disorders and sexual dysfunction are the most frequent factors affecting the long-term quality of cured patients' lives.

METHODS

A total of 96 patients consecutively treated between 2000 and 2022 with external beam radio-/chemotherapy and an interstitial brachytherapy boost for histologically verified nonmetastatic anal squamous cell carcinoma were evaluated. The median follow-up time was 15.4 years (range 13.4-17.3 years). The primary objective of the study was to assess local control (LC) and quality of life (QoL). The Czech versions of internationally validated EORTC questionnaires were used to evaluate life quality-the basic EORTC QOL-C30 v.3 and the specific QOL-ANL 27 questionnaire.

RESULTS

Local control was 85.5% at 5 years, 83.4% at 10 years, 83.4% at 15 years, and 83.4% at 20 years, and there was no dependence on clinical stage. The most common forms of acute toxicity were cutaneous and hematological but were gastrointestinal for late toxicities. In the evaluation of quality of life, 80.5% of patients alive at the time participated. In the EORTC quality of life questionnaire C30 v.3, patients rated the functional scale score as 86.2 points (standard deviation [SD] = 12.6) and the symptom score as 15.5 points (SD = 12.5). The global health score achieved 68.4 points (SD = 23.6). The most common symptoms were fatigue with 25.6 points (SD = 20.2) and diarrhea with 19.0 points (SD = 27.8). In the QOL-ANL 27 questionnaire, symptom scales assessing bowel symptoms were scored 27.5 points (SD = 19) in non-stoma patients and 11.9 points (SD = 17.2) in stoma patients. In the single-item symptom scales, the highest scores were rated for frequency of urination with 26.4 points (SD = 30.8), need to be close to a toilet with 22.4 points (SD = 27.3), and self-cleaning more often with 25.3 points (SD = 31.8). In the functional scales assessing sex life and interest, men and women reported scores of 45.2 (SD = 23) and 45.5 points (SD = 19), respectively.

CONCLUSION

Boost with interstitial HDR brachytherapy is an established safe method of anal cancer treatment, with excellent results and limited late toxicity. Functioning scales were rated relatively highly in QoL questionnaires, and the overall global health score was comparable to published data. Gastrointestinal difficulties, fatigue, and sexual dysfunction dominated the symptom scales in our cohort.

Accelerated radiotherapy in the treatment of anal squamous cell carcinoma - a single institution retrospective evaluation

BACKGROUND

The goal of treatment for anal squamous cell carcinoma (ASCC) is to preserve a functional anal sphincter and maintain the best quality of life. Surgical excision is reserved only for very early stages, and concomitant chemoradiotherapy (CHRT) is usually used in the treatment of ASCC. The aim of the study is a retrospective analysis of a group of patients with ASCC treated with CHRT using accelerated radiotherapy at the Institute of Radiation Oncology of Bulovka University Hospital in Prague (IRO BUH).

PATIENTS AND METHODS

Between 2014 and 2022, 73 patients with ASCC underwent definitive CHRT. Patients were treated with accelerated radiotherapy in 25 fractions - to the tumor and affected lymph nodes at 2.3 Gy to a dose of 57.5 Gy and to the area of the lymphatics at 1.8 Gy to a dose of 45 Gy. Concomitant chemotherapy mitomycin + 5-fluorouracil, later mitomycin + capecitabine was administered.

RESULTS

A total of 64 (87.7%) patients underwent CHRT, in the remaining 9 (12.3%) cases only radiotherapy was applied. The 2- and 5-year overall survival rates were 85.8% and 76.3%, disease-free survival 88.0% and 86.3%, local control 91.9% and 91.9%, and colostomy-free interval 68.5% and 68.5%, respectively. The median of these parameters was not reached. Acute toxicity grade G3-4 was reported in 51 (69.8%) patients, late toxicity G3-4 was detected in 10 (13.7%) cases. No grade 5 toxicity occurred.

CONCLUSION

Accelerated radiotherapy in the treatment of ASCC resulted in favorable disease control but was burdened with significant toxicity.

Chemoradiotherapy in the treatment of cervical cancer - a single institution retrospective review

BACKGROUND

The aim of this study is a retrospective analysis of treatment outcomes and toxicity in a group of patients with cervical cancer who underwent (chemo) radiotherapy at the Institute of Radiation Oncology in Bulovka University Hospital in Prague in the period 2014-2017.

PATIENTS AND METHODS

During this period, 141 patients were treated, 105 (74.5%) of them underwent combined (chemo) radiotherapy with radical intent and palliative radiotherapy was performed in 36 (25.5%) cases. According to the International Federation of Gynecology and Obstetrics (FIGO) 2009 classification, the most numerous stages were IIB in 39 (27.7%) and IIIB in 64 (45.4%) cases; according to FIGO 2018, a significant number of newly established stages is evident: IIIC1 in 55 (39.0%) patients and IIIC2 in 22 (15.6%) cases.

RESULTS

The median progression-free survival (PFS) and overall survival (OS) reached 31.3, resp. 40.1 months in the whole group. In the subgroup of patients treated with radical intent, the median PFS was 44.0 months and OS 48.8 months; in the palliative subgroup, the median PFS was 9.4 months and OS 14.8 months. In a radically treated subgroup, 7 (6.7%) patients had gastrointestinal or genitourinary manifestations of G3-4 toxicity, and overall acute toxicity (including skin and haematological reactions) of G3-4 occurred in 18 (17.1%) patients. Late toxicity of G3-4 was reported in 13 (12.4%) cases. Patients who underwent complete brachytherapy (BRT) showed significantly better survival compared to patients with a lower number of BRT fractions. The prognostic potential of PS (performance status) and anemia was confirmed; significantly longer overall survival was observed in patients in good general condition or in those without anemia.

CONCLUSION

Our results confirmed the key role of BRT for the delivery of the curative dose to the target volume. The prognostic role of PS and anemia is evident. The side effects were in acceptable limits but we expect improvements because of the use of modern radiotherapy technologies.

Total neoadjuvant therapy involving checkpoint inhibitors in locally advanced MSI/dMMR rectal cancer - a case report

BACKGROUND

Typically, the management of locally advanced rectal cancer consists of neoadjuvant chemoradiotherapy, followed by surgery and adjuvant chemotherapy. In addition to neoadjuvant chemoradiotherapy, total neoadjuvant therapy (TNT) involving radiotherapy and combined chemotherapy has been increasingly used and shown to reduce the risk of distant metastasis and improve local control. Patients with microsatellite instability and deficient mismatch repair (MSI/dMMR) tumors represent a specific group that benefits from different approaches if TNT is considered.

CASE

Our case report describes the diagnosis and treatment of a patient with locally advanced rectal cancer indicated for clinical characteristics to predictive molecular testing. Microsatellite instability was confirmed. Based on this finding, after short-course radiotherapy, she was offered neoadjuvant immunotherapy with checkpoint inhibitors. She subsequently underwent surgery with a confirmed pathologic complete response. The treatment was well-tolerated and she stays in complete remission, with a follow-up according to the standard recommendations.

CONCLUSION

This case highlights the importance of molecular testing in rectal cancer, which should be performed in all advanced cases requiring more intensive oncologic therapy than surgery alone. MSI/dMMR status indicates the need for a specific approach that may significantly improve the outcomes of these patients.