Advanced gastric cancer achieving major pathologic regression after chemoimmunotherapy combined with hypofractionated radiotherapy: A case report

BACKGROUND Currently,chemotherapy combined with immunotherapy is the established firstline standard treatment for advanced gastric cancer(GC).In addition,the combination of radiotherapy and immunotherapy is considered a promising treatment strategy.CASE SUMMARY In this report,we present a case of achieving nearly complete remission of highly advanced GC with comprehensive therapies.A 67-year-old male patient was referred to the hospital because he presented with dyspepsia and melena for several days.Based on fluorodeoxyglucose positron emission tomography/computed tomography(FDG PET/CT),endoscopic examination and abdominal CT,he was diagnosed with GC with a massive lesion and two distant metastatic lesions.The patient received mFOLFOX6 regimen chemotherapy,nivolumab and a short course of hypofractionated radiotherapy(4 Gy×6 fractions)targeting the primary lesion.After the completion of these therapies,the tumor and the metastatic lesions showed a partial response.After having this case discussed by a multidisciplinary team,the patient underwent surgery,including total gastrectomy and D2 lymph node dissection.Postoperative pathology showed that major pathological regression of the primary lesion was achieved.Chemoimmuno therapy started four weeks after surgery,and examination was performed every three months.Since surgery,the patient has been stable and healthy with no evidence of recurrence.CONCLUSION The combination of radiotherapy and immunotherapy for GC is worthy of further exploration.

Dosimetric risk factors for radiation esophagitis in patients with breast cancer following regional nodal radiation

BACKGROUND Radiation esophagitis(RE)is one of the most common clinical symptoms of regional lymph node radiotherapy for breast cancer.However,there are fewer studies focusing on RE caused by hypofractionated radiotherapy(HFRT).AIM To analyze the clinical and dosimetric factors that contribute to the development of RE in patients with breast cancer treated with HFRT of regional lymph nodes.METHODS Between January and December 2022,we retrospectively analysed 64 patients with breast cancer who met our inclusion criteria underwent regional nodal intensity-modulated radiotherapy at a radiotherapy dose of 43.5 Gy/15F.RESULTS Of the 64 patients in this study,24(37.5%)did not develop RE,29(45.3%)developed grade 1 RE(G1RE),11(17.2%)developed grade 2 RE(G2RE),and none developed grade 3 RE or higher.Our univariable logistic regression analysis found G2RE to be significantly correlated with the maximum dose,mean dose,relative volume 20-40,and absolute volume(AV)20-40.Our stepwise linear regression analyses found AV30 and AV35 to be significantly associated with G2RE(P<0.001).The optimal threshold for AV30 was 2.39 mL[area under the curve(AUC):0.996;sensitivity:90.9%;specificity:91.1%].The optimal threshold for AV35 was 0.71 mL(AUC:0.932;sensitivity:90.9%;specificity:83.9%).CONCLUSION AV30 and AV35 were significantly associated with G2RE.The thresholds for AV30 and AV35 should be limited to 2.39 mL and 0.71 mL,respectively.

Application of biological optimization of hypofractionated radiotherapy post conservative surgery for breast cancer

Objective The aim of the study was to discuss the application of biological optimization and its difference from physical optimization in hypofractionated radiotherapy for breast cancer after conservative surgery.Methods This retrospective study enrolled 15 randomly chosen patients with left-sided breast cancer who received radiotherapy.The volumetric arc therapy(VMAT)technique was used to redesign treatment plans with physical functions(PF)group,biological-physical functions combined(BF+PF and PF+BF)groups,and biological functions(BF)group.The dosimetric differences based on the above four optimization methods were assessed by calculating and analyzing the corresponding dose-volume parameters.Results The target parameters of the four groups differed significantly(P<0.05)except for the conformity index(CI).The tumor control probability(TCP)values in the BF and BF+PF groups were higher than those in the PF and PF+BF groups.Moreover,the dose-volume parameters of the ipsilateral lung in the BF group were less than those of three other groups,while the monitor unit(MU)in the BF group was approximately 16%lower than those of the PF and PF+BF groups.Conclusion Biological functions were useful to increase the equivalent uniform dose(EUD)and TCP values of the target,decrease the dose-volume parameters of the organs-at-risk(OARs),and improve treatment efficiency.

Complete pathological response in locally advanced non-small-cell lung cancer patient: A case report

BACKGROUND Chemotherapy and radiotherapy followed by durvalumab is currently the standard treatment for locally advanced node-positive non-small-cell lung cancer(NSCLC).We describe the case of a patient with locally advanced node-positive NSCLC(LA-NSCLC)treated in a phase II prospective protocol with chemotherapy,accelerated hypofractionated radiotherapy(AHRT)and surgery in the preimmunotherapy era.CASE SUMMARY A 69-year-old male,ex-smoker(20 PY),with a Karnofsky performance status of 90,was diagnosed with locally advanced squamous cell lung carcinoma.He was staged by total body computed tomography(CT)scanning,and integrated 18Ffluorodeoxyglucose positron emission tomography/CT scan[cT4 cN3 cM0,stage IIIC according to TNM(tumor-node-metastasis)8th edition]and received AHRT between chemotherapy cycles,in accordance with the study protocol(EudractCT registration 2008-006525-14).At the end of the study the patient underwent surgery,which was not part of the protocol,and showed a complete pathological response.CONCLUSION This case report confirms that AHRT can be used successfully to treat primary LA-NSCLC with bilateral mediastinal lymph node involvement.Our case is of particular interest because of the pathological response after AHRT and the lack of surgical complications.We hypothesize that this radiotherapeutic approach,with its proven efficacy,could be delivered as a short course reducing treatment costs,increasing patient compliance and reducing toxicity.We are currently investigating the possibility of combining hypofractionation,chemotherapy and immunotherapy for patients with LA-NSCLC.

A Dosimetric Comparison between Conventional Fractionated and Hypofractionated Image-guided Radiation Therapies for Localized Prostate Cancer

Background： Image-guided radiation therapy （IGRT） is the preferred method for curative treatment of localized prostate cancer, which could improve disease outcome and reduce normal tissue toxicity reaction. 1GRT using cone-beam computed tomography （CBCT） in combination with volumetric-modulated arc therapy （VMAT） potentially allows smaller treatment margins and dose escalation to the prostate. The aim of this study was to compare the difference of dos^metric diffusion in conventional IGRT using 7-field, step-and-shoot intensity-modulated radiation therapy （IMRT） and hypofractionated IGRT using VMAT for patients with localized prostate cancer. Methods： We studied 24 patients who received 78 Gy in 39 daily fractions or 70 Gy in 28 daily fractions to their prostate with/without the seminal vesicles using IMRT （n = 12） or VMAT （n = 12） for prostate cancer between November 2013 and October 2015. Image guidance was performed using kilovoltage CBCT scans equipped on the linear accelerator. Offline planning was performed using the daily treatment images registered with simulation computed tomography （CT） images. A total of 212 IMRT plans in conventional cohort and 292 VMAT plans in hypofractionated cohort were enrolled in the study. Dose distributions were recalculated on CBCT images registered with the planning CT scanner. Results： Compared with 7-field, step-and-shoot IMRT, VMAT plans resulted in improved planning target volume （PTV） D95% （7663.17 ± 69.57 cGy vs. 7789.17± 131.76 cGy, P 〈 0.001）. VMAT reduced the rectal D25 （P 〈 0.001）, D35 （P 〈 0.001）, and D50 （P 〈 0.001）, bladder V50 （P 〈 0.001）, D25 （P = 0.002）, D35 （P = 0.028）, and D50 （P = 0.029）. However, VMAT did not statistically significantly reduce the rectal V50, compared with 7-field, step-and-shoot IMRT （25.02 ± 5.54% vs. 27.43 ±8.79%, P - 0.087）. Conclusions： To deliver the hypofractionated radiotherapy in prostate cancer, VMAT significantly increased PTV D95% dose and decreased the dose of radiation delivered to adjacent normal tissues comparing to 7-field, step-and-shoot IMRT. Daily online image-guidance and better management of bladder and rectum could make a more precise treatment delivery.