Conventional four field radiotherapy versus computed tomography-based treatment planning in cancer cervix: A dosimetric study

Assessing the Adequacy of Traditional Vertebral Landmarks as Upper Border of Whole Pelvic Radiotherapy Field for Stage IB2-IIB Cervical Cancer

This study investigates the impact of insufficient common iliac lymph node (CIN) irradiation on treatment outcomes in patients with stage IB2-IIB cervical cancer receiving concurrent chemoradiotherapy (CCRT). We retrospectively analyzed 68 patients with Federation of Gynecology and Obstetrics stage IB2-IIB, treated with weekly cisplatin-based CCRT from 2008 to 2018. Patients received external-beam whole pelvic radiotherapy (WPRT) and concurrent cisplatin chemotherapy, followed by high-dose-rate brachytherapy. The WPRT upper border was at L4-5 in 61 patients and L3-4 in 7 patients. Thirty-seven patients had the CIN area fully included (full-CIN group), while 31 had partial inclusion (partial-CIN group). Recurrence rates and survival outcomes were analyzed over a median follow-up of 111 months. Patient characteristics and the irradiated dose were comparable. Treatment failure occurred in three patients (8.1%) in the full-CIN group and in six patients (19.4%) in the partial-CIN group, with CIN and para-aortic lymph node recurrence in two and one patients, respectively. The 5-year cumulative recurrence rate was 0% for the full-CIN group and 11.4% for the partial-CIN group (p = 0.04). Cause-specific survival was 100% vs. 87.1% (p = 0.025), and the overall survival was 94.3% vs. 87.1% (p = 0.44). Fully including the CIN area in WPRT is crucial for stage IB2-IIB cervical cancer. Vascular anatomical margins should be considered over vertebral landmarks.

Significant impact on the oncologic outcomes with intensity modulated radiotherapy and conformational radiotherapy over conventional radiotherapy in cervix cancer patients treated with radiotherapy

OBJECTIVE

We designed a retrospective cohort of women with cervix cancer treated by radiation therapy with an extended follow-up to evaluate if the incorporation of modern radiation techniques was a prognostic factor.

MATERIAL AND METHODS

We studied a cohort of patients with cervix cancer FIGO stage I-IVa treated in the last fifteen years. Patients were treated with radiotherapy alone (RT) or chemoradiation alone (CRT) using conventional radiotherapy (2DRT), conformational radiotherapy (3DRT), or intensity-modulated radiotherapy (IMRT) followed by high dose rate brachytherapy. Univariate and multivariate analysis was conducted to identify significant prognostic factors (p < 0.05).

RESULTS

228 patients with cervix cancer were included. The treatment groups were CRT (64.8%), and RT (34.2%), with 31.6% submitted to 2DRT and 68.4% to IMRT/3DRT. The median follow-up was 6.3 years, the OS in 5 years according to the treatment groups was 48% for CRT, and 27.8% for RT (p < 0.001). The early-stage I-IIa (p = 0.001), CRT, and IMRT/3DRT were significant factors for better overall survival (OS) in the multivariate analysis. For the cancer-specific survival (CSS), chemoradiation, age <60 years, and IMRT/3DRT were significant. Treatment with IMRT/3DRT was the only prognostic factor associated with event-free survival (EFS).

CONCLUSION

In a long-term follow-up, chemoradiation, early-clinical stage, and age <60 years were significant factors associated with better OS and CSS at 5 and 8 years. The incorporation of new radiation techniques, such as IMRT/3DRT, over time has a significant impact on all endpoints (EFS, OS, and CSS) of this cohort. These outcomes are useful to decide about the radiation technique to achieve satisfactory oncological results outside a clinical trial.

Evaluation of three dimensional conformal radiation therapy of oesophageal cancer: a dosimetric study

Aims

The main objective of this research work is to compare the dosimertic effect on lower and upper oesophagus cancer treatment using 3D conformal radiotherapy as well as to evaluate the doses administered to the organs at risk.

Materials and methods

In this study, a cohort of 30 oesophageal cancer patients between the ages of 45 and 67 years registered during March 2017 to February 2018 was considered. These patients were treated through 3D conformal radiotherapy using four-field technique. Beam energy of 15 MV from Varian DHX linear accelerator was used. The given 30 patients were divided into two groups. The 1st group of 15 patients with upper oesophagus cancer was prescribed 5000 cGy doses, and the 2nd group of remaining 15 patients with lower oesophagus cancer was prescribed 4500 cGy. Computed tomography scans of every patient were obtained and then transmitted to Eclipse TPS for generating treatment plans. All radiotherapy plans were evaluated through various dosimetric indices. Statistical analysis software SPSS was utilised to get the values of means standard error and standard deviation of these indices for the treatment plan evaluation.

Results

Uniformity index (UI) calculated for first group of patients showed difference of 7·4% from ideal value. A difference of 7% between ideal and calculated UI value was observed in 2nd group of patients. The values of other dosimetric indices like coverage, homogeneity, moderate dose homogeneity index (mDHI) and radical dose homogeneity index (rDHI) were found in limits specified by the Radiation Therapy and Oncology Group. The maximum difference of 6% was observed between the coverage mean values of 1stand 2ndgroup treatment plans.

Conclusion

For oesophageal cancer, 3D conformal radiotherapy using four-field treatment plans shows homogeneous distribution of dose around the target and limits the dose to organ at risk.

Toxicity and clinical outcomes with definitive three-dimensional conformal radiotherapy (3DCRT) and concurrent cisplatin chemotherapy in locally advanced cervical carcinoma

Objective(s)

This study aimed to retrospectively evaluate the toxicity and clinical outcomes in patients of locally advanced cervical cancer treated with three-dimensional conformal radiotherapy (3DCRT) and concurrent chemotherapy.

Material and methods

Two hundred and ten newly diagnosed patients of locally advanced cervical cancer of FIGO 2009 Stage II-III treated with 3DCRT (46 Gy/23 fractions/4½ weeks) and weekly concurrent Cisplatin (40 mg/m2), from January 2013 to 2015 were analyzed. A planning computed tomography was performed and contouring was done according to published guidelines. External radiotherapy was followed by Intracavitary brachytherapy delivered to a dose of 9 Gy HDR in 2-fractions, given one week apart. The endpoints were treatment related toxicities and clinical outcomes. Local control (LC), overall survival (OS) and disease free survival (DFS) were evaluated and toxicities were documented using the common terminology criteria for adverse events (v3.0) (CTCAE).

Results

The median follow up time was 37 (range, 19-54) months. The 3 year OS, DFS and LC were 84.2%, 80.6% and 81% respectively. Grade ≥3 acute skin, upper and lower gastrointestinal (GI) and genitourinary (GU) toxicity was observed in 3 (1.4%), 11 (5.2%), 12 (5.7%) and 0 (0%) patients, respectively. Grade ≤2 hematological toxicity was observed in 154 (73.3%) patients. Grade ≥3 late GI and GU toxicity was seen in 9 (4.2%) patients and 2 (0.9%) patients, respectively.

Conclusion

3DCRT with concurrent chemotherapy results in good loco-regional control with acceptable normal tissue toxicity. In the background of indeterminate evidence regarding routine practice of intensity modulated radiotherapy in carcinoma of the cervix, 3DCRT may be considered as the treatment of choice.

Pelvic nodal CTV from L4-L5 or aortic bifurcation? An audit of the patterns of regional failures in cervical cancer patients treated with pelvic radiotherapy

OBJECTIVE

To assess the patterns of recurrence in cervical cancer patients treated with pelvic nodal clinical target volume at L4-L5 junction instead of aortic bifurcation.

METHODS

Records of patients with locally advanced cervical cancer treated with chemo-radiation were reviewed. Patients treated with standard pelvic fields (superior border of the field at L4/L5 junction), without any radiological evidence of regional lymphadenopathy (<10 mm) were included in the study. The level of aortic bifurcation was retrospectively documented on computed tomography. Patterns of recurrences were correlated to the aortic bifurcation and the superior border of the radiation fields (L4/L5).

RESULTS

Aortic bifurcation was above the radiation fields (above L4/5) in 82 of 116 (70.7%) patients. Of the nine patients that recurred above the radiation field, 5 (55%) were above L4/5 failures, i.e. between aortic bifurcation and L4/5, and 4 (45%) had para-aortic failures. On retrospective analysis, 16 patients were found to have subcentimeter lymph nodes and higher nodal failures (7/16) were observed in patients with subcentimeter regional lymph nodes at diagnosis.

CONCLUSIONS

Superior border of nodal clinical target volume should ideally include the aortic bifurcation instead of L4-L5 inter space in patients with locally advanced cervical cancer. Radiotherapy fields need to be defined cautiously in patients with subcentimeter pelvic lymph nodes.