Assessment of Radiation Induced Pneumonitis and Pericarditis in Patients Undergoing Breast Conservative Treatment Using Hypofractionated Simultaneous Integrated Boost Technique.

INTRODUCTION: To determine the proportion of radiationinduced pneumonitis and pericarditis in patients who have received Hypo-fractionated Radiation along with simultaneous integrated boost technique after breast conservative surgery using a prospective observational study from a tertiary hospital. MATERIALS & METHODS: The incidence of radiationinduced pneumonitis and pericarditis was evaluated in all adult patients with biopsy-proven early-stage unilateral breast cancer who underwent breast-conserving surgery followed by hypo-fractionated radiation with a simultaneous integrated boost technique. Baseline assessments including a six-minute walk test, highresolution computed tomography (HRCT), pulmonary function tests (PFTs), electrocardiography (ECG) and echocardiography (ECHO) were performed. At three months post-radiation treatment, patients underwent follow-up assessments with a six-minute walk test, ECG and ECHO. At six months post-radiation treatment, patients underwent further assessments with a six-minute walk test, ECG, ECHO, PFTs, and HRCT of the thorax. Data analysis was performed using SPSS version 19. RESULTS: Our study investigated the incidence of acute radiation-induced pneumonitis and pericarditis in patients treated with hypofractionated VMAT-SIB technique in 20 eligible early breast cancer patients. The study found that the technique is feasible and achieves encouraging dosimetric parameters, including well achieved ipsilateral lung and heart doses. The reduced treatment time of 3-4 weeks compared to the previous 6-7 weeks with sequential boost was also found to be desirable in resource-constrained settings. The incidence of acute radiation pneumonitis and pericarditis was acceptable and comparable to existing data, with 90% of patients experiencing grade 1 radiation pneumonitis according to CTCAE v5.0. Post-treatment pulmonary function tests showed significant changes, particularly in patients who had received neoadjuvant chemotherapy and nodal irradiation. The six-minute walk test and Borg scale also showed a significant positive correlation with pulmonary function tests. There was no significant pericarditis during the follow-up. The study proposes that the hypofractionated radiotherapy using VMAT-SIB is a suitable alternative to conventional fractionation, with acceptable acute toxicities, but longer follow-up is required to assess the impact on late toxicities. CONCLUSION: Our research has shown that hypofractionated adjuvant radiotherapy with SIB is a safe and feasible treatment for patients with early breast cancer. This treatment method doesn't pose any significant short-term risks to the lungs or heart, and the SIB technique provides better coverage, conformity and sparing of organs at risk. Additionally, patients have reported positive cosmetic outcomes with this treatment. However, to make more accurate conclusions, we need to conduct further studies with larger sample sizes and longer follow-up periods to evaluate the potential longterm side effects of this treatment using VMAT in whole breast radiation.

Image-Guided Brachytherapy a Comparison Between 192Ir and 60Co Sources in Carcinoma Uterine Cervix.

INTRODUCTION: Combination of external beam radiotherapy (EBRT) and High Dose Rate (HDR) brachytherapy (BT) with concurrent chemotherapy (Cisplatin 40mg/m2/weekly) is the standard treatment of approach for the carcinoma of uterine cervix. In this study for image based HDR brachytherapy of intracavitary both 192Ir and 60Co sources were used for dosimetry and the dose distribution compared between point doses and volume doses as per the recommendation of ICRU89 and GEC-ESTRO on 3D image based planning. The dosimetry and clinical outcome will decide decisionmaking on choice of radionuclide for HDR brachytherapy of cervix in addition to economic reason. MATERIALS AND METHODS: The Study conducted for 27 patients of cancer cervix stage IIB or IIIB with vaginal involvement limited to the upper third of vagina. All patients underwent concurrent chemoradiation Cisplatin 40mg/m2 weekly throughout EBRT by 3D conformal therapy 46Gy in 23# followed by two fractions of HDR brachytherapy with 9Gy/1Fr. Post implants 3mm slice selection of pelvic CT scans performed with ring applicator in place followed by T2 weighted paracorpal or paracoronal section of MRI imaging. The solid ring applicator (AL13017000) from library used for applicator reconstruction. Initially all plan calculated with TG-43 formalism using 192Ir radionuclide (Varian, GammaMed HDR Plus source) and then modelled 60Co radionuclide (Eckert < Ziegler BEBIG GmbH, Co0. A86) used for dose computation. ICRU89 recommended points and volumes of targets and OARs evaluated and compared. RESULTS: The study concludes that 60Co based point-A, BICRU and RICRU doses showed a comparable result with that of 192Ir HDR source based dosimetry. The volume based criterion for the target such as GTV, CTVHR, CTVIR for D90, D98, V150%and V200% are all within 5% dose level comparing two sources. CONCLUSION: 60Co a viable alternate to 192Ir by taking into consideration frequency of source exchange and cost reserve with comparable dosimetry.

Impact of GBBS algorithm on post-mastectomy scar boost irradiation of breast using catheter flap.

PURPOSE: Post-mastectomy radiation therapy significantly reduces locoregional recurrence rates, which can be achieved with external beam radiotherapy delivered to chest wall, followed by scar irradiation either by electron or high-dose-rate (HDR) mould brachytherapy. The present study evaluates dosimetric advantage of Acuros® BV, a TG-186 MBDCA, over TG-43 formalism using 192Ir source for HDR brachytherapy in chest wall scar boost using catheter flap. MATERIAL AND METHODS: A total of 25 patients, free of cardiac and pulmonary co-morbidities, who met the inclusion criteria were involved in the study. Catheter flap made of silicon with 20 channels was used to deliver a total dose of 7.5 Gy/3 fx by HDR surface mould brachytherapy to delineated scar volume. Plan was optimized with iterative method to obtain desired results with TG-43 formalism, followed by Acuros® BV (GBBS algorithm) without altering dwell positions or time. The two algorithm plans were analyzed qualitatively and quantitatively with dose-volume histograms. RESULTS: The mean D98% CTV-HDR_evl coverage decreased by 1.16% compared to TG-43, and near-maximum dose decreased by 8.18% (p = 0.000), mean Dmax dose to CTV-HDR_evl, and mean Dmean dose was lesser by 6.25% (p = 0.000) and 10.82% (p = 0.000), respectively, compared to TG-43. Heart D2% showed significant results, whereas Dmedian (cGy) revealed very significant difference. A 5 mm thick skin contour showed statistically significant results (p = 0.000) for V150% and V200%. CONCLUSIONS: The presented data showed how Acuros® BV, algorithm-based calculation in scar boost irradiation of breast, accounting for a mass density of the medium and scatter condition, considered actual dose prediction in a medium.

Study of the dosimetric differences between (192)Ir and (60)Co sources of high dose rate brachytherapy for breast interstitial implant.

AIM: The study intends to compare (192)Ir source against the (60)Co source for interstitial breast metal implant in high dose rate brachytherapy. BACKGROUND: Few studies have been reported to compare (60)Co and (192)Ir on HDR brachytherapy in gynaecology and prostate cancer and very few with reference to breast cancer. MATERIALS AND METHODS: Twenty patients who had undergone interstitial template guided breast implant were treated in HDR (192)Ir brachytherapy unit. Plans were generated substituting (60)Co source without changing the dwell positions and optimization. Cumulative dose volume histograms were compared. RESULTS: The reference isodose line enclosing CTV (CTVref) and the 2.34% difference seen in the volume enclosed by the reference isodose line (V ref) between the two isotopes show small but statistically significant difference (p < 0.05). In DHI, no difference was observed in the relative dose between the two sources (p = 0.823). The over dose volume index showed 11% difference. The conformity index showed 2.32% difference compared to (192)Ir (p < 0.05). D mean (%) and D max (%) for the heart, ipsilateral lung, ipsilateral ribs, skin presented very small difference. V 5% and V 10% of the heart shows 25% and 32% difference in dose. D 2cc (%) and D 0.1cc (%) for the contralateral breast, contralateral lung and D 2cc (%) of the skin displayed significant difference (p < 0.05). However, D 0.1cc (%) of the skin indicated no noteworthy difference with p = 0.343. CONCLUSION: Based on the 3D dosimetric analysis of patient plans considered in this study, most of the DVH parameters showed statistically significant differences which can be reduced by treatment planning optimization techniques. (60)Co isotope can be used as a viable alternative because of its long half-life, logistic advantages in procurement, infrequent need of source replacement and disposal of used source.

Dosimetric comparison of Acuros™ BV with AAPM TG43 dose calculation formalism in breast interstitial high-dose-rate brachytherapy with the use of metal catheters.

PURPOSE: Radiotherapy for breast cancer includes different techniques and methods. The purpose of this study is to compare dosimetric calculations using TG-43 dose formalism and Varian Acuros™ BV (GBBS) dose calculation algorithm for interstitial implant of breast using metal catheters in high-dose-rate (HDR) brachytherapy, using (192)Ir. MATERIAL AND METHODS: Twenty patients who were considered for breast conservative surgery (BCS), underwent lumpectomy and axillary dissection. These patients received perioperative interstitial HDR brachytherapy as upfront boost using rigid metal implants. Whole breast irradiation was delivered TG-43 after a gap of two weeks. Standard brachytherapy dose calculation was done by dosimetry. This does not take into account tissue heterogeneity, attenuation and scatter in the metal applicator, and effects of patient boundary. Acuros™ BV is a Grid Based Boltzmann Solver code (GBBS), which takes into consideration all the above, was used to compute dosimetry and the two systems were compared. RESULTS: Comparison of GBBS and TG-43 formalism on interstitial metal catheters shows difference in dose prescribed to CTV and other OARs. While the estimated dose to CTV was only marginally different with the two systems, there is a significant difference in estimated doses of starting from 4 to 53% in the mean value of all parameters analyzed. CONCLUSIONS: TG-43 algorithm seems to significantly overestimate the dose to various volumes of interest; GBBS based dose calculation algorithm has impact on CTV, heart, ipsilateral lung, heart, contralateral breast, skin, and ribs of the ipsilateral breast side; the prescription changes occurred due to effect of metal catheters, inhomogeneities, and scatter conditions.

Optimization of high-dose-rate intracavitary brachytherapy schedule in the treatment of carcinoma of the cervix.

PURPOSE: At our institute, we use high-dose-rate (HDR) intracavitary brachytherapy (ICBT) schedule of 9 Gy per fraction for two fractions after external beam radiotherapy (EBRT) in patients with advanced carcinoma of the cervix. But American Brachytherapy Society recommends that individual fraction size should be less than 7 Gy per fraction in such patients. We present the results of comparison of our institution standard schedule with biologically equivalent dose of 6.8 Gy per fraction for three fractions in terms of local control, disease-free survival, and late toxicity. METHODS AND MATERIALS: Between October 2003 and August 2007, 104 patients with carcinoma of the uterine cervix (Stages IIB and IIIB) were treated with EBRT and HDR ICBT. After EBRT, patients were randomized to one of the treatment arms. ICBT dose in Control Arm A (n=52) was 9 Gy per fraction in two fractions, 1 week apart, and in Study Arm B (n=52), it was 6.8 Gy per fraction in 3 fractions, 1 week apart. RESULTS: The median followup was 31.48 months. The 3-year actuarial local control was 81.35% in Arm A and 65.18% in Arm B (p=0.0423), and the 3-year actuarial disease-free survival was 64.97% in Arm A and 49.47% in Arm B (p=0.0393). The 3-year actuarial risk of developing any Grade 3 or worse late toxicity was 7.47% in Arm A and 3.57% in Arm B (p=0.2907). CONCLUSION: In our setup, HDR brachytherapy at 9 Gy per fraction in two fractions is safe and effective with good local control, survival, and manageable normal tissue toxicity.

Prognostic value of response to external radiation in stage IIIB cancer cervix in predicting clinical outcomes: a retrospective analysis of 556 patients from India.

BACKGROUND AND PURPOSE: To evaluate the prognostic significance of response to external beam radiation (EBRT) in predicting the clinical outcomes in stage IIIB cancer cervix and to find out factors affecting response to EBRT. PATIENTS AND METHODS: This retrospective study included 556 patients of cancer cervix stage IIIB treated between 1996 and 2001 with EBRT (46Gy/23fx/4.5 weeks) followed by intracavitary radiotherapy (ICRT). At the end of EBRT, response to EBRT was grouped as 'no gross residual tumor'(NRT) or 'gross residual tumor'(GRT). RESULTS: Follow up ranged from 2 to 93 months with a median of 36 months. Median dose to point A was 81Gy. At the end of EBRT, 393 patients (70.7%) attained NRT response. NRT responders had significantly better 5 year pelvic control, disease free survival (DFS) and overall survival (OS) than those who had a GRT response (75.6 vs. 54.6%; 60.6 vs. 31.9% and 62.6 vs. 33.7%, respectively; all P values <0.0001). Apart from response to EBRT, overall treatment time also has emerged as an independent factor to affect all clinical outcomes in multivariate analysis but age had significant impact on pelvic control only. Age was the only factor, which significantly influenced the response to EBRT in univariate as well as multivariate analysis (P=<0.001, OR=1.973, 95% C.I. 1.357-2.868). Patients with age more than 50 years had more NRT response (77%) than patients with age less than 50 years (63.8%). CONCLUSIONS: Patients who attain NRT response to EBRT will have an impressive long term pelvic control, DFS and OS in stage IIIB cancer cervix. Older patients (>or=50 years) attain significantly higher NRT rates than younger patients.

Results of salvage radiotherapy after inadequate surgery in invasive cervical carcinoma patients: a retrospective analysis.

PURPOSE: To evaluate the results of salvage radiotherapy (RT) after inadequate surgery in patients with invasive carcinoma of the cervix. METHODS AND MATERIALS: Between 1996 and 2001, 105 invasive cervical carcinoma patients were treated at our center with external beam RT with or without intracavitary RT after having undergone total/subtotal hysterectomy at outside institutions. RESULTS: The median follow-up was 34 months. The gap between surgery and RT was 23-198 days (median, 80). Clinically visible residual disease was present in 81 patients (77.1%). Total hysterectomy had been done in 82 patients (78%) and subtotal hysterectomy in 23 patients (22%). The 5-year overall survival, disease-free survival, and pelvic control rates of all patients were 55.2%, 53.3%, and 72.4%, respectively. On univariate analysis, older age, total hysterectomy, hemoglobin level >10 g% before RT, nonsquamous histologic type, use of intracavitary RT, a shorter gap between surgery and RT, and the absence of, or a small volume of, residual disease favorably affected the outcome. The 5-year actuarial rate of late toxicity (Radiation Therapy Oncology Group Criteria) was 19% in the rectum, 4.8% in the bladder, 24.8% in the skin, and 14.3% in the small intestine. CONCLUSIONS: Inadequate and inappropriate surgery in invasive cervical cancer with resulting gross residual disease is common in India. Factors such as the use of intracavitary RT, the correction of anemia, and a shorter gap between surgery and RT will enable postoperative RT to achieve acceptable results with minimal morbidity.