Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients

Exercise interventions for adults with cancer receiving radiation therapy alone

BACKGROUND

Radiation therapy (RT) is given to about half of all people with cancer. RT alone is used to treat various cancers at different stages. Although it is a local treatment, systemic symptoms may occur. Cancer- or treatment-related side effects can lead to a reduction in physical activity, physical performance, and quality of life (QoL). The literature suggests that physical exercise can reduce the risk of various side effects of cancer and cancer treatments, cancer-specific mortality, recurrence of cancer, and all-cause mortality.

OBJECTIVES

To evaluate the benefits and harms of exercise plus standard care compared with standard care alone in adults with cancer receiving RT alone.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid), CINAHL, conference proceedings and trial registries up to 26 October 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled people who were receiving RT without adjuvant systemic treatment for any type or stage of cancer. We considered any type of exercise intervention, defined as a planned, structured, repetitive, objective-oriented physical activity programme in addition to standard care. We excluded exercise interventions that involved physiotherapy alone, relaxation programmes, and multimodal approaches that combined exercise with other non-standard interventions such as nutritional restriction.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology and the GRADE approach for assessing the certainty of the evidence. Our primary outcome was fatigue and the secondary outcomes were QoL, physical performance, psychosocial effects, overall survival, return to work, anthropometric measurements, and adverse events.

MAIN RESULTS

Database searching identified 5875 records, of which 430 were duplicates. We excluded 5324 records and the remaining 121 references were assessed for eligibility. We included three two-arm RCTs with 130 participants. Cancer types were breast and prostate cancer. Both treatment groups received the same standard care, but the exercise groups also participated in supervised exercise programmes several times per week while undergoing RT. Exercise interventions included warm-up, treadmill walking (in addition to cycling and stretching and strengthening exercises in one study), and cool-down. In some analysed endpoints (fatigue, physical performance, QoL), there were baseline differences between exercise and control groups. We were unable to pool the results of the different studies owing to substantial clinical heterogeneity. All three studies measured fatigue. Our analyses, presented below, showed that exercise may reduce fatigue (positive SMD values signify less fatigue; low certainty). • Standardised mean difference (SMD) 0.96, 95% confidence interval (CI) 0.27 to 1.64; 37 participants (fatigue measured with Brief Fatigue Inventory (BFI)) • SMD 2.42, 95% CI 1.71 to 3.13; 54 participants (fatigue measured with BFI) • SMD 1.44, 95% CI 0.46 to 2.42; 21 participants (fatigue measured with revised Piper Fatigue Scale) All three studies measured QoL, although one provided insufficient data for analysis. Our analyses, presented below, showed that exercise may have little or no effect on QoL (positive SMD values signify better QoL; low certainty). • SMD 0.40, 95% CI -0.26 to 1.05; 37 participants (QoL measured with Functional Assessment of Cancer Therapy-Prostate) • SMD 0.47, 95% CI -0.40 to 1.34; 21 participants (QoL measured with World Health Organization QoL questionnaire (WHOQOL-BREF)) All three studies measured physical performance. Our analyses of two studies, presented below, showed that exercise may improve physical performance, but we are very unsure about the results (positive SMD values signify better physical performance; very low certainty) • SMD 1.25, 95% CI 0.54 to 1.97; 37 participants (shoulder mobility and pain measured on a visual analogue scale) • SMD⁠⁠⁠⁠⁠⁠ 3.13 (95% CI 2.32 to 3.95; 54 participants (physical performance measured with the six-minute walk test) Our analyses of data from the third study showed that exercise may have little or no effect on physical performance measured with the stand-and-sit test, but we are very unsure about the results (SMD 0.00, 95% CI -0.86 to 0.86, positive SMD values signify better physical performance; 21 participants; very low certainty). Two studies measured psychosocial effects. Our analyses (presented below) showed that exercise may have little or no effect on psychosocial effects, but we are very unsure about the results (positive SMD values signify better psychosocial well-being; very low certainty). • SMD 0.48, 95% CI -0.18 to 1.13; 37 participants (psychosocial effects measured on the WHOQOL-BREF social subscale) • SMD 0.29, 95% CI -0.57 to 1.15; 21 participants (psychosocial effects measured with the Beck Depression Inventory) Two studies recorded adverse events related to the exercise programmes and reported no events. We estimated the certainty of the evidence as very low. No studies reported adverse events unrelated to exercise. No studies reported the other outcomes we intended to analyse (overall survival, anthropometric measurements, return to work).

AUTHORS' CONCLUSIONS

There is little evidence on the effects of exercise interventions in people with cancer who are receiving RT alone. While all included studies reported benefits for the exercise intervention groups in all assessed outcomes, our analyses did not consistently support this evidence. There was low-certainty evidence that exercise improved fatigue in all three studies. Regarding physical performance, our analysis showed very low-certainty evidence of a difference favouring exercise in two studies, and very low-certainty evidence of no difference in one study. We found very low-certainty evidence of little or no difference between the effects of exercise and no exercise on quality of life or psychosocial effects. We downgraded the certainty of the evidence for possible outcome reporting bias, imprecision due to small sample sizes in a small number of studies, and indirectness of outcomes. In summary, exercise may have some beneficial outcomes in people with cancer who are receiving RT alone, but the evidence supporting this statement is of low certainty. There is a need for high-quality research on this topic.

A nomogram prediction model for lymph node metastasis risk after neoadjuvant chemoradiotherapy in rectal cancer patients based on SEER database

Background

Rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) may have a lower cancer stage and a better prognosis. Some patients may be able to avoid invasive surgery. It is critical to accurately assess lymph node metastases (LNM) after neoadjuvant chemoradiotherapy. The goal of this study is to identify clinical variables associated with LNM and to develop a nomogram for LNM prediction in rectal cancer patients following nCRT.

Methods

From 2010 to 2015, patients were drawn from the Surveillance, Epidemiology, and End Results (SEER) database. To identify clinical factors associated with LNM, the least absolute shrinkage and selection operator (LASSO) aggression and multivariate logistic regression analyses were used. To predict the likelihood of LNM, a nomogram based on multivariate logistic regression was created using decision curve analyses.

Reslut

The total number of patients included in this study was 6,388. The proportion of patients with pCR was 17.50% (n=1118), and the proportion of patients with primary tumor pCR was 20.84% (n = 1,331). The primary tumor was pCR in 16.00% (n=213) of the patients. Age, clinical T stage, clinical N stage, and histology were found to be significant independent clinical predictors of LNM using LASSO and multivariate logistic regression analysis. The nomogram was developed based on four clinical factors. The 5-year overall survival rate was 78.9 percent for those with ypN- and 66.3 percent for those with ypN+, respectively (P<0.001).

Conclusion

Patients over 60 years old, with clinical T1-2, clinical N0, and adenocarcinoma may be more likely to achieve ypN0. The watch-and-wait (WW) strategy may be considered. Patients who had ypN0 or pCR had a better prognosis.

Predicting the Risk of Radiation Pneumonitis and Pulmonary Function Changes after Breast Cancer Radiotherapy

Background

Radiotherapy plays an important role in the treatment of breast cancer. In the process of radiotherapy, the underling lung tissue receives higher doses from treatment field, which led to incidence of radiation pneumonitis.

Objective

The present study aims to evaluate the predictive factors of radiation pneumonitis and related changes in pulmonary function after 3D-conformal radiotherapy of breast cancer.

Material and Methods

In prospective basis study, thirty-two patients with breast cancer who received radiotherapy after surgery, were followed up to 6 months. Respiratory symptoms, lung radiologic changes and pulmonary function were evaluated. Radiation pneumonitis (RP) was graded according to common terminology criteria for adverse events (CTCAE) version 3.0. Dose-volume parameters, which included percentage of lung volume receiving dose of d Gy (V₅-V₅₀) and mean lung dose (MLD), were evaluated for RP prediction. Pulmonary function evaluated by spirometry test and changes of FEV1 and FVC parameters.

Results

Eight patients developed RP. Among the dose-volume parameters, V₁₀ was associated to RP incidence. When V₁₀<40% and V₁₀≥40% the incidences of RP were 5.26% and 61.54%, respectively. The FEV1 and FVC had a reduction 3 and 6 months after radiotherapy, while only FEV1 showed significant reduction. The FEV1 had more reduction in the patients who developed RP than patients without RP (15.25±3.81 vs. 9.2±0.93).

Conclusion

Pulmonary function parameters, especially FEV1, significantly decreased at 3 and 6 months after radiotherapy. Since most patients with breast cancer who developed RP did not show obvious clinical symptoms, so spirometry test is beneficial to identify patients with risk of radiation pneumonitis.

CT findings of acute radiation-induced pneumonitis in breast cancer

OBJECTIVES

To evaluate the CT findings of acute radiation pneumonitis (RP) in breast cancer patients undergoing post-operative radiotherapy, and to analyze clinicodosimetric factors associated with acute RP.

METHODS

Between 2015 and 2017, 61 patients with breast cancer who underwent follow-up chest CT at 3 months after radiotherapy were analyzed. The degree of acute RP on CT was evaluated by the change of extent and scoring system (grade 0, no RP; Grade 1, ground-glass opacities (GGOs); Grade 2, GGOs and/or consolidations; Grade 3, clear focal consolidation; Grade 4, dense consolidation). The dosimetric parameters were calculated from the dose-volume histogram of RT.

RESULTS

The acute RP on CT was scored as follows: Grade 0, in 37.7%, Grade 1 in 13.1%, Grade 2 in 44.3%, and Grade 3 in 4.9%. The median extent of RP in patients with Grades 1 to 3 was 6.2 ml (range, 0.2-95.9). There were no clinicodosimetric factors significantly associated with the presence of RP or its severity. One patient developed symptomatic RP.

CONCLUSION

This study showed no correlation between acute RP and clinicodosimetric factors, and acute RP based on CT findings were much more common than symptomatic RP.

ADVANCES IN KNOWLEDGE

CT findings of acute RP or extent of RP were not significantly related to clinicodosimetric factors in breast cancer patients.

Visceral Adipose Mass and Radiation Pneumonitis After Concurrent Chemoradiotherapy in Patients With Non-small-cell Lung Cancer

AIM

To investigate whether muscle and adipose mass are associated with radiation pneumonitis (RP) in patients with non-small cell lung cancer undergoing preoperative concurrent chemoradiotherapy.

PATIENTS AND METHODS

We calculated body mass index and determined skeletal muscle, psoas muscle, visceral adipose tissue (VAI), and subcutaneous adipose tissue indices, and visceral-to-subcutaneous adipose tissue area ratio for patients using computed tomography. We examined their relationship with grade 2 or more RP.

RESULTS

Among 94 patients, 28 experienced grade 2 or more RP. On multivariate analysis, only VAI was associated with grade 2 or more RP (all p=0.026). The 6-month incidence rates of grade 2 or more RP were 21.4% and 36.8% in patients with VAI <39 and ≥39 cm ² /m ² , respectively.

CONCLUSION

High visceral adipose mass is associated with grade 2 or more RP in patients undergoing preoperative concurrent chemoradiotherapy. Measuring visceral adipose mass may help to predict RP occurrence. Further studies are needed to validate our findings.

Dosimetric comparison of volumetric-modulated arc therapy and helical tomotherapy for adjuvant treatment of bilateral breast cancer

Purpose:

Dosimetric comparison between volumetric-modulated arc therapy (VMAT) and helical tomotherapy (HT) in the treatment of bilateral breast cancer (BBC).

Materials and methods:

Ten patients treated on HT were selected retrospectively. Dose prescription was 50 Gy in 25 fractions to breast/chest wall and supraclavicular fossa (SCF) while tumour bed was simultaneously boosted to 61 Gy in 25 fractions. VMAT plans were made with four mono-isocentric partial arcs. The monitoring unit (MU) and treatment time were used to quantify the treatment efficiency. Target volumes were compared for homogeneity index (HI), conformity index (CI) while organs at risk (OARs) were compared for relevant dose volumes and integral doses (IDs).

Result:

For targets, no significant difference is observed between VMAT and HT in CI but VMAT could give better HI. The mean lung dose, V20 and V5 is 10·6 Gy versus 8·4 Gy (p-value 0·03), 12% versus 11·5% (p-value 0·5) and 78·1% versus 43·4% (p-value 0·005), respectively. The mean heart dose, V30 and V5 is 4·9 Gy versus 4·7 Gy (p-value 0·88), 0·5% versus 1·5% (p-value 0·18) and 26·2% versus 22·8% (p-value 0·4). Integral dose (ID) for the whole body and heart are comparable: 289 Gy kg versus 299 Gy kg (p-value 0·24) and 2·9 Gy kg versus 2·8 Gy kg (p-value 0·80). ID for lungs was significantly higher with VMAT: 7·9 Gy kg versus 6·3 Gy kg (p-value 0·03). There is a 53% reduction in treatment time and 78% in MU with VMAT against HT.

Conclusion:

VMAT can generate clinically acceptable plans comparable to HT for BBC. HT shows better control over low dose spillage in lungs compared to VMAT thereby increasing ID to lungs. VMAT shows better homogeneity and efficient treatment delivery than HT.

A Retrospective Analysis of Dose Distribution and Toxicity in Patients with Left Breast Cancer Treated with Adjuvant Intensity-Modulated Radiotherapy: Comparison with Three-Dimensional Conformal Radiotherapy

Background

A better understanding of the organs-at-risk (OAR) dose metrics and the related toxicity induced by radiotherapy (RT) for left breast cancer (BC) will improve the quality of life. This study addressed the issue for left-BC patients treated with intensity-modulated radiotherapy (IMRT) compared to three-dimensional conformal radiotherapy (3D-CRT).

Patients and Methods

Between 2012 and 2018, 308 left-BC patients underwent adjuvant RT at our hospital. Before June 2015, 134 patients were treated with 3D-CRT. Thereafter, 174 patients underwent IMRT. The patient’s characteristics in the IMRT group did not significantly different compared to those in the 3D-CRT group.

Results

Among the total study population, the incidence of ≥grade 2 radiation dermatitis (RID) was 17.3%. Higher volumes receiving 105% (≥5.7%) and 107% (≥1%) of prescribed dose and 3D-CRT technique were associated with a higher risk of RID. Regarding lung toxicity, the mean lung dose (≥10.2Gy) and V20 (≥20%) of ipsilateral lung were significantly associated with the incidence of RT-induced pulmonary changes. By dosimetry analysis, IMRT achieved better dose conformity and delivered lower mean doses to heart and ipsilateral lung compared to 3D-CRT. Furthermore, propensity sore and multivariate analysis showed that IMRT technique helped to reduce RT-induced dermatitis and lung toxicity.

Conclusion

Our data suggest that the volume of OAR exposed to higher doses is a predictor of RT-induced toxicity. Adjuvant RT with IMRT technique offered better dose conformity and spared high-dose levels to OARs to reduce radiation-related morbidity for BC patients.

Preoperative assessment of lymph node metastasis in clinically node-negative rectal cancer patients based on a nomogram consisting of five clinical factors

Background

Currently, reliable approaches for accurate assessment of lymph node metastases (LNM), which is an important indication of preoperative chemoradiotherapy (CRT), are not available for clinically node-negative rectal cancer patients. This study aims to identify clinical factors associated with LNM and to establish a nomogram for LNM prediction in clinically node-negative rectal cancer patients.

Methods

The least absolute shrinkage and selection operator (LASSO) aggression and multivariate logistic regression analyses were applied to identify clinical factors associated with LNM. A nomogram was established to predict the probability of LNM in clinically node-negative rectal cancer patients based on the multivariate logistic regression model.

Results

Six potential risk factors were selected on the basis of LASSO aggression analysis, and five of them were identified as independent risk factors for LNM based on multivariate analysis, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, white blood cell count (WBC), and preoperative elevated tumor markers. A nomogram consisting of the five clinical factors was established and showed good discrimination. Decision curve analysis demonstrated that the established nomogram was reliable and accurate for LNM prediction in clinically node-negative rectal cancer patients.

Conclusions

A nomogram based on five clinical factors, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, WBC, and preoperative elevated tumor markers, are useful for assessing LNM in clinically node-negative rectal cancer patients, which is important for preoperative CRT regimens.

Developing of predictive models for pneumonitis with forward variable selection and LASSO logistic model for breast cancer patients treated with 3D-CRT

Purpose: To develop a multiple logistic regression model as normal tissue complication probability model by least absolute shrinkage and selection operator (LASSO) technique in breast cancer patients treated with three-dimensional conformal radiation therapy (3D-CRT), we focused on the changes of pulmonary function tests to achieve the optimal predictive parameters for the occurrence of symptomatic radiation pneumonitis (SRP).

Materials and methods: Dosimetric and spirometry data of 60 breast cancer patients were analyzed. Pulmonary function tests were done before RT, after completion of RT, 3, and 6 months after RT. Multiple logistic regression model was used to obtain the effective predictive parameters. Forward selection method was applied in NTCP model to determine the effective risk factors from obtained different parameters.

Results: Symptomatic radiation pneumonitis was observed in five patients. Significant changes in pulmonary parameters have been observed at six months after RT. The parameters of mean lung dose (MLD), bridge separation (BS), mean irradiated lung volume (ILVmean), and the percentage of the ipsilateral lung volume that received dose of 20 Gy (IV20) introduced as risk factors using the LASSO technique for SRP in a multiple normal tissue complication probability model in breast cancer patients treated with 3D-CRT. The BS, central lung distance (CLD) and ILV in tangential field have obtained as 23.5 (20.9-26.0) cm, 2.4 (1.5-3.3) cm, and 12.4 (10.6-14.3) % of lung volume in radiation field in patients without pulmonary complication, respectively.

Conclusion: The results showed that if BS, CLD, and ILV are more than 23 cm, 2 cm, and 12%, respectively, so incidence of SRP in the patients will be considerable. Our multiple NTCP LASSO model for breast cancer patients treated with 3D-CRT showed that in order to have minimum probability of SRP occurrence, parameters of BS, IV20, ILV and especially MLD would be kept in minimum levels. Considering dose-volume histogram, the mean lung dose factor is most important parameter which minimizing it in treatment planning, minimizes the probability of SRP and consequently improves the quality of life in breast cancer patients.

An in silico comparative dosimetric study of postmastectomy locoregional irradiation using intensity-modulated vs 3-dimensional conventional radiotherapy

An in silico dosimetric evaluation of intensity-modulated radiation therapy (IMRT) vs 3-dimensional conventional radiation therapy (3D-CRT) treatment plans in postmastectomy radiation therapy (PMRT) to the chest wall and regional lymphatics was conducted. Twenty-five consecutive patients with breast cancer referred for locoregional PMRT, stages T_2-4 with N_1-3, were planned to receive 50 Gy in 25 fractions with IMRT. Additionally, a 3D-CRT plan was generated using identical contours for the clinical target volumes (CTV), planning target volumes (PTV), and organs at risk (OAR). Treatment plans were assessed using dose-volume histogram (DVH) parameters of D₉₈, D₉₅, D₅₀, D₂, and homogeneity index for individual CTVs and PTVs. OARs evaluated were ipsilateral and contralateral lungs, heart, spinal cord, and opposite breast. Most DVH parameters pertaining to CTVs and PTVs significantly favored IMRT. V₂₀ for ipsilateral and contralateral lungs, D₃₃ of heart and maximum dose to spinal cord favored IMRT (all p < 0.001). The mean dose to the opposite breast was significantly lesser with 3D-CRT (5.8 ± 1.8 Gy vs 2.0 ± 1.0 Gy, p < 0.001). Thus, except for the mean dose to the opposite breast, the compliance to DVH constraints applied to PTV and OARs were significantly better with IMRT. At a median follow-up of 76 months (7-91), none had locoregional failure or pulmonary or cardiac morbidity. For PMRT, requiring comprehensive irradiation to both chest wall and regional lymphatics, IMRT offers superior dosimetric advantages over 3D-CRT. This was also corroborated by long-term outcomes in these patients treated with IMRT.

Propensity-score-matched evaluation of the incidence of radiation pneumonitis and secondary cancer risk for breast cancer patients treated with IMRT/VMAT

Propensity score matching evaluates the treatment incidence of radiation-induced pneumonitis (RP) and secondary cancer risk (SCR) after intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for breast cancer patients. Of 32 patients treated with IMRT and 58 who received VMAT were propensity matched in a 1:1 ratio. RP and SCR were evaluated as the endpoints of acute and chronic toxicity, respectively. Self-fitted normal tissue complication probability (NTCP) parameter values were used to analyze the risk of RP. SCRs were evaluated using the preferred Schneider's parameterization risk models. The dosimetric parameter of the ipsilateral lung volume receiving 40 Gy (IV₄₀) was selected as the dominant risk factor for the RP NTCP model. The results showed that the risks of RP and NTCP, as well as that of SCR of the ipsilateral lung, were slightly lower than the values in patients treated with VMAT versus IMRT (p ≤ 0.01). However, the organ equivalent dose and excess absolute risk values in the contralateral lung and breast were slightly higher with VMAT than with IMRT (p ≤ 0.05). When compared to IMRT, VMAT is a rational radiotherapy option for breast cancer patients, based on its reduced potential for inducing secondary malignancies and RP complications.

The feasibility of a heart block with an electron compensation as an alternative whole breast radiotherapy technique in patients with underlying cardiac or pulmonary disease

PURPOSE

We aimed to evaluate the feasibility of the heart block with electron compensation (HBE) technique, based on three-dimensional conformal radiotherapy (3D-CRT) in left-sided breast cancer patients with underlying cardiac or pulmonary disease.

METHODS

Twenty patients with left-sided breast cancer who were treated with whole breast radiotherapy (WBRT) were included in this study. Intensity-modulated radiotherapy (IMRT), 3D-CRT, and HBE treatment plans were generated for each patient. Based on the 3D-CRT plan, the HBE plan included a heart block from the medial tangential field to shield the heart and added an electron beam to compensate for the loss in target volume coverage. The dosimetric parameters for the heart and lung and the target volume between the three treatment types were compared.

RESULTS

Of the three plans, the HBE plan yielded the most significant reduction in the doses received by the heart and lung (heart Dmean: 5.1 Gy vs. 12.9 Gy vs. 4.0 Gy and lung Dmean: 11.4 Gy vs. 13.2 Gy vs. 10.5 Gy, for 3D-CRT, IMRT, and HBE, respectively). Target coverage with all three techniques was within the acceptable range (Dmean 51.0 Gy vs. 51.2 Gy vs. 50.6 Gy, for 3D-CRT, IMRT, and HBE, respectively).

CONCLUSIONS

The HBE plan effectively reduced the amount of radiation exposure to the heart and lung. It could be beneficial for patients who are vulnerable to radiation-related cardiac or pulmonary toxicities.

Which simultaneous-integrated boost (SIB) intensity-modulated radiotherapy (IMRT) technique is dosimetrically superior in the treatment of breast cancer; volumetric-modulated arc therapy (VMAT) or fixed field (ff) IMRT?

Background and purpose

To determine which concomitant boost technique is dosimetrically superior in the treatment of breast cancer; volumetric-modulated arc therapy (VMAT) or fixed field intensity-modulated radiotherapy (ff-IMRT).

Materials and methods

In total, 30 breast patients were re-planned with both VMAT and fixed field concomitant boost intensity-modulated radiotherapy techniques. A hybrid technique was used delivering 80% of the dose through tangential beams and 20% through an integrated boost. A two-tailed t-test sample for means was used to compare the dosimetric differences between the techniques.

Results

Maximum dose was statistically lower for VMAT; 103·2 versus 103·7% for ff-IMRT along with statistically lower V2 Gy doses to the contralateral lung (0·7 versus 1·6%) and heart for both left- (19·0%/22·6%), and right- (5·5%/8·8%) sided patients, respectively. ff-IMRT boasted significantly lower ipsilateral lung V20, V18 and V10 Gy (7·9/8·6/13·1 versus 8·1/8·8/13·4%) than VMAT, respectively. No differences were found with minimum coverage, mean dose and V5 Gy to all organs at risk (OARs).

Conclusion

VMAT and ff-IMRT techniques demonstrate excellent target coverage and OAR sparing facilitated by the hybrid planning technique and deep inspiration breath hold. There is no obvious dosimetrically superior option between the two techniques. Reduced treatment times with VMAT make it more desirable to implement clinically.

Surgically treated oesophageal cancer developed in a radiated field: Impact on peri-operative and long-term outcomes

BACKGROUND

The objectives of this study were to compare peri-operative and long-term outcomes from oesophageal cancer (EC) (i) that arose in a previously radiated field (ECRF) versus primary (PEC) and among ECRF patients and (ii) radiotherapy-induced (RIEC) versus non-radiotherapy-induced EC (NRIEC).

METHODS

Data were collected from 30 European centres from 2000 to 2010. Two thousand four hundred eighty nine EC patients surgically treated were included in the PEC group and 136 in the ECRF group, NRIEC group (n = 61) and RIEC group (n = 75). Propensity score matching analyses were used to compensate for differences in baseline characteristics.

RESULTS

Compared to the PEC group, the ECRF group was characterised by less use of neoadjuvant chemoradiotherapy (0% versus 29.5%; P < 0.001), less pathological stage III/IV (31.6% versus 39.2%, P = 0.036), greater incidence of R1/2 margins (21.3% versus 10.9%; P < 0.001), increased in-hospital mortality (14.0% versus 7.1%; P = 0.003) and overall morbidity (68.4% versus 56.4%, P = 0.006). After matching, 5-year overall (28.8% versus 50.5%; hazard ratio [HR] = 1.53, 95% confidence interval [CI]: 1.15-2.04; P = 0.003) and event-free (32.2% versus 42.5%; HR = 1.56, 95% CI: 1.18-2.05; P = 0.002) survivals were significantly reduced in the ECRF group. There were no significant differences in incidence or pattern of tumour recurrence. Comparing RIEC and NRIEC groups, there were no significant differences in short- or long-term outcomes before and after matching.

CONCLUSIONS

ECRF is associated with poorer long-term survival related to a reduced utilisation of neoadjuvant chemoradiotherapy and an increased incidence of tumour margin involvement at surgery. Outcomes appear to be dictated by the limitations related to previous radiotherapy administration more than the radiotherapy-induced carcinogenesis.

A Study on Dosimetric Outcomes and Acute Toxicity of Post Mastectomy Adjuvant Hypofractionated Radiotherapy for Breast Cancer

INTRODUCTION

Hypofractionated External Beam Radiotherapy (HFRT) is a relatively new adjuvant Radiotherapy (RT) schedule for breast cancers following breast conservation surgery and less commonly, following mastectomy. Here we report our experience on normal tissue exposure and acute toxicity of HFRT after mastectomy.

AIM

To assess the dosimetric outcomes and acute toxicity profile of adjuvant HFRT following mastectomy for breast cancer.

MATERIALS AND MATERIALS

This prospective observational study considered consecutive patients planned for adjuvant HFRT (42.5 Gy in 16 sessions delivered over 3 weeks) to the chest wall with/without regional nodes between October 2014 and June 2015. The dosimetric parameters including dose homogeneity to the target volume and exposure to heart and lung were analyzed. Acute haematological and dermatological toxicity was recorded until upto three months after completion of RT.

RESULTS

Among the 56 patients treated with HFRT, the mean age was 49 years (range: 28-69 years). Pathologically positive nodes and ≥pT3 primary was observed in 44 (78.6%) and 12 (21.4%) patients, respectively. Majority (87.5%) received prior adjunct chemotherapy. RT to the supraclavicular fossa was delivered for 39 (69.6%) patients. The mean V90 and V95 to the Planning Target Volume (PTV) were 95% (± 3.3%) and 93% (± 4%), respectively. The maximum dose received was on average 47.7 Gy (112%; range: 46.2-48.5 Gy). The mean lung dose was 10.2 Gy (± 3.5 Gy) and V20 was 20.9% (± 6%). The mean V25 to heart was 6.6% (± 4.8%) for left sided and 0% for right sided tumours (p=0.001). Acute skin toxicity peaked at completion of RT and was tolerable (grade 0, I, II and III reactions were 75%, 16% and 1.8%, respectively). No patient had ≥ grade III haematological toxicity, and treatment was not interrupted for any patient.

CONCLUSION

Adjuvant HFRT could be planned while meeting the dose constraints to normal tissues in all patients and was well tolerated, with mild to moderate acute adverse effects that did not warrant any therapeutic intervention or treatment interruption.

Normal tissue complication probability modeling for cochlea constraints to avoid causing tinnitus after head-and-neck intensity-modulated radiation therapy

Background

Radiation-induced tinnitus is a side effect of radiotherapy in the inner ear for cancers of the head and neck. Effective dose constraints for protecting the cochlea are under-reported. The aim of this study is to determine the cochlea dose limitation to avoid causing tinnitus after head-and-neck cancer (HNC) intensity-modulated radiation therapy (IMRT).

Methods

In total 211 patients with HNC were included; the side effects of radiotherapy were investigated for 422 inner ears in the cohort. Forty-nine of the four hundred and twenty-two samples (11.6 %) developed grade 2+ tinnitus symptoms after IMRT, as diagnosed by a clinician. The Late Effects of Normal Tissues–Subjective, Objective, Management, Analytic (LENT-SOMA) criteria were used for tinnitus evaluation. The logistic and Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) models were used for the analyses.

Results

The NTCP-fitted parameters were TD₅₀ = 46.31 Gy (95 % CI, 41.46–52.50), γ₅₀ = 1.27 (95 % CI, 1.02–1.55), and TD₅₀ = 46.52 Gy (95 % CI, 41.91–53.43), m = 0.35 (95 % CI, 0.30–0.42) for the logistic and LKB models, respectively. The suggested guideline TD₂₀ for the tolerance dose to produce a 20 % complication rate within a specific period of time was TD₂₀ = 33.62 Gy (95 % CI, 30.15–38.27) (logistic) and TD₂₀ = 32.82 Gy (95 % CI, 29.58–37.69) (LKB).

Conclusions

To maintain the incidence of grade 2+ tinnitus toxicity <20 % in IMRT, we suggest that the mean dose to the cochlea should be <32 Gy. However, models should not be extrapolated to other patient populations without further verification and should first be confirmed before clinical implementation.