Why "radiation oncology"

Cetuximab and anemia prevention in head and neck cancer patients undergoing radiotherapy

BACKGROUND

Epidermal growth factor receptor (EGFR) activation is associated with increased production of interleukin 6 (IL6), which is intensified by radiotherapy (RT) induced inflammatory response. Elevated IL6 levels intensifies RT-induced anemia by upregulating hepcidin causing functional iron deficiency. Cetuximab, an EGFR inhibitor, has been associated with lower rates of anemia for locally advanced head and neck squamous cell carcinoma (HNSCC). We hypothesized that concomitant cetuximab could prevent RT-induced anemia.

METHODS

We queried our institutional head and neck cancers database for non-metastatic HNSCC cases that received RT with concomitant cetuximab or RT-only between 2006 and 2018. Cetuximab was administered for some high-risk cases medically unfit for platinum agents per multidisciplinary team evaluation. We only included patients who had at least one complete blood count in the 4 months preceding and after RT. We compared the prevalence of anemia (defined as hemoglobin (Hb) below 12 g/dL in females and 13 g/dL in males) and mean Hb levels at baseline and after RT. Improvement of anemia/Hb (resolution of baseline anemia and/or an increase of baseline Hb ≥1 g/dL after RT), and overall survival (OS) in relation to anemia/Hb dynamics were also compared.

RESULTS

A total of 171 patients were identified equally distributed between cetuximab-plus-RT and RT-only groups. The cetuximab-plus-RT group had more locally-advanced stage, oropharyngeal and high grade tumors (p < 0.001 for all). Baseline anemia/Hb were similar, however anemia after RT conclusion was higher in the cetuximab-plus-RT vs RT-only (63.5% vs. 44.2%; p = 0.017), with a mean Hb of 11.98 g/dL vs. 12.9 g/dL; p = 0.003, for both respectively. This contributed to significantly worse anemia/Hb improvement for cetuximab-plus-RT (18.8% vs. 37.2%; p = 0.007). This effect was maintained after adjusting for other factors in multivariate analysis. The prevalence of iron, vitamin-B12 and folate deficiencies; and chronic kidney disease, was non-different. Baseline anemia was associated with worse OS (p = 0.0052) for the whole study cohort. Nevertheless, improvement of anemia/Hb was only marginally associated with better OS (p = 0.068).

CONCLUSIONS

In contrast to previous studies, cetuximab was not associated with lower rates of anemia after RT for nonmetastatic HNSCC patients compared to RT-alone. Dedicated prospective studies are needed to elucidate the effect of cetuximab on RT-induced anemia.

Stereotactic ablative body radiotherapy boost for cervical cancer when brachytherapy boost is not feasible

BACKGROUND

The purpose of this study was to analyze the treatment efficacy and safety of stereotactic ablative body radiotherapy (SABR) boost for cervical cancer patients not amenable to brachytherapy.

METHODS

A retrospective review of the medical records from single institution of 25 eligible patients was performed. The patients underwent pelvic radiotherapy (RT) in 25 or 28 fractions with a median dose of 45 Gy (range 44-50.4 Gy). SABR boost was delivered after pelvic RT, with a median dose of 25 Gy (range 20-33 Gy), and a median fraction number of 5 (range 4-6). 21 patients with a follow-up period of more than one year were included in the toxicity analysis, and hematuria and hematochezia that occurred later than 3 months after the RT were graded.

RESULTS

The median follow-up period after radiotherapy was 2.85 years (range 0.33-6.60). The 3-year local control, locoregional control, disease-free survival, and overall survival rates were 80.9%, 75.8%, 40.9%, and 77.1%, respectively. 5 patients experienced grade 3 toxicity (3 genitourinary, 3 gastrointestinal), and no grade 4-5 toxicity was reported. Univariate analysis showed that cumulative D_2cc in equivalent dose in 2 Gy fractions (EQD2) of rectum was marginally predictive for any grade of hematochezia (P = 0.051). Cumulative D_2cc EQD2 of bladder was not predictive for hematuria. In the receiver operating characteristic (ROC) curve analysis, the optimal threshold of cumulative rectal D_2cc EQD2 was 81.2 Gy for any grade of hematochezia.

CONCLUSION

SABR boost for cervical cancer was effective and tolerable. Although it cannot substitute brachytherapy, it can be a treatment option when brachytherapy is not possible.

Efficacy of radiotherapy for the treatment of cystic echinococcosis in naturally infected sheep

BACKGROUND

Radiotherapy is commonly used to treat cancers. To date, there has been no study focusing on the effects of radiotherapy on hydatid disease in large animals. In this study, we aim to investigate the efficiency and safety of radiotherapy for treating hydatid disease caused by Echinococcus granulosus in naturally infected sheep.

METHODS

Ultrasound was used to screen naturally infected sheep in an echinococcosis endemic area in Xinjiang, China. A computer tomography (CT) scan confirmed the presence of hydatid cysts. Twenty sheep naturally infected with E. granulosus in the liver and/or lungs were randomly assigned into four groups receiving no irradiation, or X-ray irradiation of low (30 Gy), medium (45 Gy), and high dose (60 Gy), respectively. After three months of radiotherapy, a CT scan was performed to measure the changes in the cysts. The hepatic parasite cysts and host tissues were collected for histology and gene expression analysis.

RESULTS

In the animals subject to irradiation, no significant differences were observed in their appetite, daily activities, and weight before and after radiotherapy. Severe calcification was noticed in the cysts subject to a high dose of radiation compared with the groups subject to low and medium doses. Hematoxylin and eosin staining showed that irradiation contributed to the damage of the cyst structure and nucleus in the germinal layers. Quantitative PCR demonstrated that expression of TPX and HSP70 significantly decreased in a dose-dependent manner (P < 0.05). The expression of the EPC1 decreased in the medium- and high-dose groups compared with the low-dose group (P < 0.05). Meanwhile, the expression of radiation-related apoptosis genes caspase-3 and Gadd45 decreased with an increase in the irradiation dose.

CONCLUSIONS

Radiotherapy is an option with satisfactory efficiency and safety for treating cystic echinococcosis in sheep with partial response or stable disease at month 3. In future, inhibition of cystic activity using radiotherapy may serve as a new regimen for treating hydatid disease.

Comparison between weekly cisplatin-enhanced radiotherapy and cetuximab-enhanced radiotherapy in locally advanced head and neck cancer: first retrospective study in Asian population

AIM

To present a direct comparison between chemotherapy-enhanced radiotherapy (CERT) and biotherapy-enhanced radiotherapy (BERT) in locally advanced head and neck cancer.

METHODS

It is a retrospective analysis of 53 patients with locally advanced head and neck cancer treated from August 2006 to December 2008. For CERT, patients received weekly cisplatin (40 mg/m² ) and for BERT, a loading dose of 400 mg/m² of cetuximab given one week prior to radiotherapy followed by 250 mg/m² given weekly along with radiotherapy. Disease-free survival (DFS) and overall survival (OS) were computed with Kaplan-Meier curve with log-rank test for comparison between the two groups. Multivariate Cox proportional hazards regression analysis was performed to estimate the impact of known relevant prognostic factors on DFS and OS.

RESULTS

The median DFS was significantly better with CERT than BERT group (50.82 vs 11.66 months; P = 0.031). The 3 years DFS was significantly higher in CERT group than in BERT group (60.0% vs 14.3%; P = 0.022). The median OS was significantly better with CERT than BERT group (53.61 vs 32.55 months; P = 0.044). The 3 years OS was also significantly higher in CERT group than in BERT group (74.0% vs 42.1%; P = 0.032). There were no significant differences in acute toxicities of all grade and grade ≥3 between the two groups. The compliance to treatment and assisted feeding dependency for more than 6 months duration were also not significantly different.

CONCLUSION

CERT is associated with better outcome with no significantly increased acute toxicities compared to BERT.

Comparing treatment outcomes of different chemotherapy sequences during intensity modulated radiotherapy for advanced N-stage nasopharyngeal carcinoma patients

Background

N-stage is related to distant metastasis of nasopharyngeal carcinoma (NPC) patients. We performed this study to compare the efficacy of different chemotherapy sequences in advanced N-stage (N2 and N3) NPC patients treated with intensity modulated radiotherapy (IMRT).

Methods

From 2001 to 2008, 198 advanced N-stage NPC patients were retrospectively analyzed. Thirty-three patients received IMRT alone. Concurrent chemoradiotherapy (CCRT) was delivered to 72 patients, neoadjuvant chemotherapy (NACT) + CCRT to 82 patients and CCRT + adjuvant chemotherapy (AC) to 11 patients.

Results

The 5-year overall survival rate, recurrence-free survival rate, distant metastasis-free survival rate and progress-free survival rate were 47.7% and 73.1%(p<0.001), 74.5% and 91.3% (p = 0.004), 49.2% and 68.5% (p = 0.018), 37.5% and 63.8% (p<0.001) in IMRT alone and chemoradiotherapy group. Subgroup analyses indicated that there were no significant differences among the survival curves of CCRT, NACT + CCRT and CCRT + AC groups. The survival benefit mainly came from CCRT. However, there was only an improvement attendency in distant metastasis-free survival rate of CCRT group (p = 0.107) when compared with RT alone group, and NACT + CCRT could significantly improve distant metastasis-free survival (p = 0.017).

Conclusions

For advanced N-stage NPC patients, NACT + CCRT might be a reasonable treatment strategy.

Partial frequency of radiation pneumonitis and its association with the energy and treatment technique in patients with breast cancer, Isfahan, Iran

BACKGROUND

Breast cancer is the most common type of cancer among women, and the second cause of cancer mortality after pulmonary cancer in this gender. Radiotherapy is one of the major treatments, which locally controls the disease and prohibits in recurrency. Radiation pneumonitis is one of the radiotherapy complications, which usually occurs within 1.5-3 months after radiotherapy. As there is no precise estimation concerning this complication in Isfahan, partial frequency of radiation pneumonitis and its association with the energy and treatment technique in patients with breast cancer were evaluated.

MATERIALS AND METHODS

This was an analytic cross-sectional study performed in 2010 in university referral center. A total of 382 patients with breast cancer, undergone surgery and referred for radiotherapy entered the study. A posterior and anterior and lateral X-Rays were taken as control images before starting radiotherapy and all X-Rays were repeated after 3-4 months post radiotherapy. The occurrence of radiotherapy pneumonitis was evaluated by the same radiologist. Data were analyzed through SPSS version 20.

RESULTS

Out of 382 patients undergone breast conservative surgery (BCS) or modified radical mastectomy (MRM), and radiotherapy, 60 patients had pneumonitis of whom 6 patients underwent BCS and were treated by tangential field (three cases by Co 60 and three cases by PH 9). The rest of radiotherapy pneumonitis patients (n = 54) underwent MRM of whom, 42 cases were treated by one-field and 12 by two-field treatment techniques.

CONCLUSION

Incidence of radiotherapy pneumonitis was different with respect to the adopted technique (one-field, two-field and tangential) (P = 0.023), with the highest association with two-field radiotherapy.

Intensity-modulated radiotherapy using simultaneous-integrated boost for definitive treatment of locally advanced mucosal head and neck cancer: outcomes from a single-institution series

INTRODUCTION

The study aims to report outcomes for patients treated using intensity-modulated radiotherapy (IMRT) with simultaneous-integrated boost and weekly cisplatin for American Joint Committee on Cancer stage III/IV mucosal head and neck squamous cell carcinomas (HNSCCs).

METHODS

Records for 67 patients treated definitively with IMRT for HNSCC were reviewed. By including only those treated with weekly cisplatin, 45 patients were eligible for analysis. Treatment outcomes, effect of patient, tumour and treatment characteristics on disease recurrence were analysed.

RESULTS

All patients completed IMRT to 7000 cGy in 35 fractions, with concurrent weekly cisplatin 40 mg/m(2) (median 6 cycles). Median follow-up was 28 months for living patients. Two-year loco-regional recurrence-free, metastasis-free and overall survival were 85.4, 81.0 and 87.4%, respectively. Local recurrence occurred in three patients, and distant recurrence in eight patients.

CONCLUSIONS

Our results show efficacy of IMRT and weekly cisplatin in the treatment of stage III/IV HNSCC at our institution with respect to loco-regional control.

Computerized estimation of patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy

We have developed a computerized method for estimating patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy. The patient setup errors were estimated based on a template-matching technique that compared the portal image and a localized pelvic template image with a clinical target volume produced from a digitally reconstructed radiography (DRR) image of each patient. We evaluated the proposed method by calculating the residual error between the patient setup error obtained by the proposed method and the gold standard setup error determined by consensus between two radiation oncologists. Eleven training cases with prostate cancer were used for development of the proposed method, and then we applied the method to 10 test cases as a validation test. As a result, the residual errors in the anterior-posterior, superior-inferior and left-right directions were smaller than 2 mm for the validation test. The mean residual error was 2.65 ± 1.21 mm in the Euclidean distance for training cases, and 3.10 ± 1.49 mm for the validation test. There was no statistically significant difference in the residual error between the test for training cases and the validation test (P = 0.438). The proposed method appears to be robust for detecting patient setup error in the treatment of prostate cancer radiotherapy.

Distinguishing patients with celiac disease by quantitative analysis of videocapsule endoscopy images

BACKGROUND

Although videocapsule endoscopy images are helpful in the evaluation of celiac disease, their interpretation is subjective. Quantitative disease markers could assist in determining the extent of villous atrophy and response to treatment.

METHOD

Capsule endoscopy images were acquired from celiac patients with small bowel pathology (N=11) and from control patients (N=10). Image resolution was 576x576 pixels in dimension, 256 grayscale levels, and had a 2 s(-1) frame rate. Pixel brightness and image texture were measured over 10x10 pixel subimages and then averaged for 56x56 subimages per frame. Measurements were obtained at five locations from proximal to distal small intestine in each patient. At each location, measurements were calculated using 200 consecutive image frames (100s). Mean frame-to-frame pixel brightness, image texture, and periodicity in brightness, an estimate of wall motion or intestinal motility, were computed and used for classification with a nonlinear discriminant function.

RESULTS

From pooled data, celiac images had greater texture than did images from control patients (p<0.001) and exhibited more frame-to-frame brightness variation as well (p=0.032). The dominant period of brightness was longer in celiacs (p=0.001), possibly indicating decreased motility. Using the markers for three-dimensional nonlinear classification of celiacs versus controls, sensitivity was 92.7% and specificity was 93.5%. The relationship between dominant period and small intestinal transit time was approximately linear for both celiacs and controls (r(2)=0.42 and r(2)=0.55, respectively).

CONCLUSIONS

Videocapsule images can be quantified to detect villous atrophy throughout the small intestine, and to distinguish individuals with celiac disease from individuals lacking mucosal atrophy.

Interaction of ionizing radiation and ZRBA1, a mixed EGFR/DNA-targeting molecule

ZRBA1 is a molecule termed 'combi-molecule' designed to induce DNA-alkylating lesions and to block epidermal growth factor receptor (EGFR) tyrosine kinase. Owing to its ability to downregulate the EGFR tyrosine kinase-mediated antiapoptotic signaling and DNA repair proteins, we inferred that it could significantly sensitize cells to ionizing radiation. Using the MDA-MB-468 human breast cancer cell line in which ZRBA1 has already been reported to induce significant EGFR/DNA-targeting potency, the results showed that: (i) concurrent administration of ZRBA1 and 4 Gy radiation led to a significant decrease in cell viability, (ii) the greater efficacy of the combination was sequential, being limited to conditions wherein the drug was administered concurrently with radiation or before radiation, and (iii) the efficacy enhancement of the combination was further confirmed by clonogenic assays from which a dose enhancement factor of 1.34 could be observed at survival fraction of 0.01. Flow cytometric analysis showed significant enhancement of cell cycle arrest in G2/M (P<0.046, irradiated cells vs. cells treated with ZRBA1 and radiation) and increased apoptosis when ZRBA1 was combined with radiation. Likewise, significant levels of double-strand breaks were observed for the combination, as determined by neutral comet assay (P<0.045, irradiated cells vs. cells treated with ZRBA1 and radiation). These results in toto suggest that the superior efficacy of the ZRBA1 plus radiation combination may be secondary to the ability of ZRBA1 to arrest the cells in G2/M, a cell cycle phase in which tumor cells are sensitive to radiation. Furthermore, the increased levels of DNA damage, combined with the concomitant downregulation of EGFR-mediated signaling by ZRBA1, may account for the significant levels of cell killing induced by the combination.