Intensity-modulated whole pelvic radiotherapy provides effective dosimetric outcomes for cervical cancer treatment with lower toxicities

Comparison of Acute Gastrointestinal Toxicity of Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiotherapy in Patients of Carcinoma Cervix

Introduction Cervical cancer is the most common gynaecological malignancy worldwide, with a higher prevalence in middle- and low-income countries. Chemoradiotherapy, followed by intracavitary brachytherapy, is the treatment of choice in locally advanced cervical cancer. The most common acute side effect of external beam radiotherapy (EBRT) is bowel toxicity in the form of diarrhoea and abdominal cramps. The treatment techniques of EBRT were revolutionised with the advent of intensity modulation. This study aims to prospectively analyse whether the dosimetric advantage of intensity-modulated radiotherapy (IMRT) over three-dimensional conformal radiotherapy (3DCRT) is translated clinically into a decrease in acute toxicity. Method Twenty-four patients were randomised into two groups: the 3DCRT and the IMRT. Acute gastrointestinal (GI) toxicity was assessed during treatment using radiation therapy oncology group grading. The factors under consideration were age, stage of the disease, treatment technique, chemotherapy, and the intention of therapy (radical or adjuvant). The mean bowel bag dose of the two techniques was analysed. Result Among the factors under consideration, it was found that the treatment technique was the only factor that had a significant association with acute bowel toxicity in both univariate (p = 0.036) and multivariate analyses (p = 0.028). The mean V25 (the volume receiving 25 Gy), V45, and V50 of the bowel bag in the IMRT arm were significantly less than the 3DCRT arm. Grades 2 and 3 acute bowel toxicities were also higher in the 3DCRT arm. Conclusion The treatment technique is essential to determining acute GI toxicity during pelvic radiotherapy. With IMRT, the dose to the bowel bag and, in turn, the acute bowel toxicity can be reduced.

miR-16-5p modulates the radiosensitivity of cervical cancer cells via regulating coactivator-associated arginine methyltransferase 1

This study was to investigate the expression of coactivator-associated arginine methyltransferase 1 (CARM1) and miR-16-5p in cervical cancer (CC), and explore their roles in radioresistance. Western blot and immunohistochemistry were used to detect the expression of CARM1 in tissues and cells. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of miR-16-5p. CC cells received different doses of X-ray exposure, and then cell counting kit-8 method and colony formation assay were used to detect cell proliferation. Apoptosis was detected by flow cytometry. Then we used Targetscan database to predict that CARM1 is a potential target of miR-16-5p, and further verified the targeting relationship between them by western blot, RT-PCR and dual luciferase reporter experiments. We demonstrated that CARM1 were highly expressed in CC tissues and radio-resistant CC cells, while miR-16-5p expression was low. Under irradiation, up-regulation of CARM1 can induce radiotherapy resistance of CC cells, while overexpression of miR-16-5p or CARM1 knockdown could inhibit the survival of CC cell and induced apoptosis. CARM1 was verified as a target for miR-16-5p. Besides, up-regulation of CARM1 reversed the increase in radiosensitivity induced by miR-16-5p. Collectively, we concluded that miR-16-5p promoted the radiosensitivity of CC cells by targeting CARM1.

IMRT and brachytherapy comparison in gynaecological cancer treatment: thinking over dosimetry and radiobiology

Background

The role of radiotherapy and brachytherapy in the management of locally advanced cervical and endometrial cancer is well established. However, in some cases, intracavitary brachytherapy (ICBRT) is not recommended or cannot be carried out. We aimed to investigate whether external-beam irradiation delivered by means of intensity-modulated radiation therapy (IMRT) might replace ICBRT in gynaecological cancer when the standard ICBRT boost delivering cannot be administered for technical or clinical reasons.

Materials and methods

Fifteen already delivered treatments for gynaecological cancer patients were analysed. The treatments were performed through 3-dimensional conformal radiotherapy (3D-CRT) to the whole-pelvis up to the dose of 45–50.4 Gy followed by a boost dose administered with ICBRT in high-dose-rate or pulsed-dose-rate modality. For each patient, IMRT plans were elaborated to mimic the ICBRT. We analysed the ICBRT boost versus IMRT boost in terms of dosimetric and radiobiological aspects.

Results

Mean conformity index value calculated on boost volume was 0.73 for ICBRT and 0.97 for IMRT. Mean conformation number was 0.24 for ICBRT boost and 0.78 for IMRT boost. Mean normal tissue complication probability (NTCP) values for 3D-CRT plus ICBRT and for IMRT (pelvis plus boost) were, respectively, 28% and 5% for rectum; 1.5% and 0.1% for urinary bladder and 8.9% and 6.1% for bowel.

Conclusions

Our findings suggest that IMRT may represent a viable alternative in delivering the boost in patients diagnosed with gynaecological cancer not amenable to ICBRT.

Radical radiotherapy in patients with cervix uteri carcinoma: experience of Ondokuz Mayis University

Background

Radical radiotherapy is the standard treatment for patients with locally advanced cervix uteri carcinoma (FIGO stage IB2–IVA). Worldwide, incidence and mortality rates vary among regions because of differences in lifestyles and treatment standards. Herein, we evaluated the outcomes of radical radiotherapy in patients with locally advanced cervix uteri carcinoma from the middle Black Sea region of Turkey.

Methods

We retrospectively reviewed the records of 64 consecutive patients with locally advanced cervix uteri carcinoma who were treated from January 2013 to 2016 in our radiation oncology department. All patients staging and radiotherapy planning were performed with modern imaging techniques including magnetic resonance imaging and positron-emission-tomography/computed tomography before radical radiotherapy. Thereafter, all of them were treated with external beam radiotherapy and concurrent cis-platinum-based chemotherapy followed by three-dimensional intra-cavitary high-dose-rate brachytherapy.

Results

The median age at diagnosis was 54.5 years. The median follow-up period was 21 months. Acute grade 3 toxicity was detected in 3.1% of patients. Late toxicity was not detected in any patient. The 1- and 3-year progression-free survival rates were 83.6 and 67.5%, respectively. The 1- and 3-year overall survival rates were 95.7 and 76.9%, respectively. The most important prognostic factor was the FIGO stage. Distant metastasis was the most common cause of death in patients with locally advanced cervix uteri carcinoma despite radical radiotherapy.

Conclusions

In patients with locally-advanced cervix uteri carcinoma from the middle Black Sea region of our developing country, acceptable toxicity and survival rates are achieved similar to the recent literature from developed countries with using of modern staging, planning and radical radiotherapy techniques. However, recurrence was mostly in the form of distant metastases and further investigations on systemic therapies are required.

High precision radiotherapy including intensity-modulated radiation therapy and pulsed-dose-rate brachytherapy for cervical cancer: a retrospective monoinstitutional study

Purpose

To analyse the survival outcomes and toxicity profile of patients treated with pulsed-dose-rate (PDR) brachytherapy (BT) after intensity-modulated radiation therapy (IMRT) for uterine cervical cancer in a single institution.

Material and methods

Between March 2011 and December 2014, 50 patients with histologically proven stages IB1-IVB cervical cancer were treated with IMRT followed by PDR-BT boost. Radiation treatment consisted of IMRT to pelvic with or without paraaortic lymph nodes to a total dose of 45-50.4 Gy. Weekly concomitant chemotherapy was administered to 45 patients. PDR-BT boost was delivered with a median dose of 30 Gy to the high-risk clinical target volume (HR-CTV) after a median time of 14 days since IMRT. Acute and late toxicity were evaluated by Radiation Therapy Oncology Group (RTOG) - European Organization for Research and Treatment of Cancer (EORTC) scoring criteria and Subjective Objective Management Analytic-Late Effects of Normal Tissues (SOMA-LENT) criteria.

Results

Two patients had tumour persistence at 6 months after the end of BT. After a median follow-up of 33 months, 6 distant metastases with or without regional relapse were observed. The 1- and 5-year progression-free survival was 83% (95% CI: 69-91%) and 76% (95% CI: 61-86%), whereas the 3- and 5-year overall survival was 91% (95% CI: 78-97%) and 76% (95% CI: 56-88%), respectively. Urinary and rectal toxicity higher than grade 2 was observed in 6.3% and 17% of patients, respectively. Five patients (10.6%) had grade 4 gastrointestinal toxicity requiring colostomy.

Conclusions

Our study confirms that the combination of IMRT and PDR-BT can be considered an effective treatment for cervical cancer, ensuring high local control, despite the high percentage of locally advanced disease.

Radiographic Number of Positive Pelvic Lymph Nodes as a Prognostic Factor in Cervical Cancer Treated With Definitive Concurrent Chemoradiotherapy or Intensity-Modulated Radiotherapy

Background: This study aims to assess the prognostic significance of radiographic numbers of positive pelvic lymph nodes (PLNs) in patients with cervical cancer treated with definitive concurrent chemoradiotherapy (CCRT) or intensity-modulated radiotherapy (IMRT).

Methods: We conducted a retrospective study that included 164 eligible adult patients with cervical cancer who were treated with definitive CCRT or IMRT at our institution from 2009 to 2016. After exclusion of 50 patients, a total of 114 patients whose clinicopathological data and follow-up were finally analyzed. The radiographic numbers of positive PLNs were assessed by pretreatment magnetic resonance imaging (MRI) or computed tomography (CT). The criterion for a positive lymph node was defined as a short-axis diameter >1 cm. Using the Kaplan–Meier method and the Cox proportional hazards regression model, we assessed the overall survival (OS), cancer-specific survival (CSS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRFS).

Results: The median follow-up duration was 40 (range: 2–100) months. For patients with 0, 1–2, and ≥3 positive PLNs, the estimated 3-year OS were 85.4% vs. 82.4% vs. 59.7% (p = 0.035), CSS were 90.1% vs. 86.1% vs. 62.9% (p = 0.010), DMFS were 89.4% vs. 91.3% vs. 49.6% (p < 0.001), and LRFS were 77.8% vs. 73.4% vs. 70% (p = 0.690). Per the multivariate Cox regression, positive PLNs ≥3 (HR, 2.51; 95% CI: 1.09–5.80; p = 0.031) and non-squamous cell carcinoma type (HR, 2.82; 95% CI: 1.19–6.69; p = 0.018) were unfavorable factors for the OS. Besides, positive PLNs ≥3 was the independent factor for the CSS (HR, 3.38; 95% CI: 1.32–8.67; p = 0.011) and DMFS (HR, 6.83; 95% CI: 2.62–17.83; p < 0.001). The patients that were treated without intracavitary brachytherapy exhibited inferior LRFS (HR, 13.15; 95% CI: 2.66–65.10; p = 0.002).

Conclusions: The radiographic number of positive PLNs (≥ 3) is an independent prognostic factor for OS, CSS, and DMFS in patients treated with definitive CCRT or IMRT.

Cervical cancer treated with reduced-volume intensity-modulated radiation therapy base on Sedlis criteria (NCCN VS RTOG)

OBJECTIVE

This study aimed to evaluate the clinical efficacy of different target volumes in pelvic radiotherapy in postoperative treatment of cervical cancer based on the Sedlis criteria.

METHODS

Patients who admitted to our department for post-operative radiotherapy of cervical cancer from December 2001 to December 2011 and met the Sedlis criteria were retrospectively analysed. The incidences of acute and late radiation injuries, and overall, disease-free and tumour-specific survival with reduced-volume pelvic and whole-pelvis radiotherapy were evaluated and compared.

RESULTS

A total of 371 patients were included in the study, including 239 receiving whole-pelvis radiotherapy and 132 receiving reduced-volume pelvic radiotherapy. The volume of contours for mean PTV volumes, bilateral femoral heads and small intestine volumes in reduced-volume pelvic radiotherapy were lower than whole-pelvis radiotherapy; the results were similar to the V10, V20, V30, V40 and V45 for pelvic bone marrow and small intestine dose volume (both p < 0.05). The acute radiation injury observed in the two groups was mainly haematologic toxicity and upper and lower gastrointestinal symptoms. The incidences of acute radiation injury, and late radiation injury of gastrointestinal and urinary tracts were both significantly lower with reduced-volume pelvic radiotherapy than with whole-pelvis radiotherapy (both p < 0.05). Moreover, there was no significant difference in the incidence of lower extremity oedema, or 2-year or 5-year overall, disease-free or tumour-specific survival between groups (all p > 0.05).

CONCLUSION

Reduced-volume pelvic radiotherapy could relieve acute and late radiation injuries, especially myelosuppression, and did not affect long-term survival. Advanced in knowledge: Our study shows that reduced-volume base on National Comprehensive Cancer Network 2016 is more fit for cervical cancer than others.

Dosimetric influence of photon beam energy and number of arcs on volumetric modulated arc therapy in carcinoma cervix: A planning study

AIM

Aim of the present study was to compare the dosimetric impact of different photon beam energies and number of arcs in the treatment of carcinoma cervix.

BACKGROUND

Carcinoma cervix is a common cancer in women worldwide with a high morbidity rate. Radiotherapy is used to treat such tumours. Volumetric Modulated Arc Therapy (VMAT) is considered superior to other techniques with multiple arcs and energies.

MATERIALS AND METHODS

Twenty patients with carcinoma cervix underwent radiotherapy in a prospective observation study conducted at our institute. Volumetric modulated arc plans with 6 MV, 10 MV and 15 MV photon energies using single arc (SA) and dual arc (DA) were generated. Several physical indices for planning target volume (PTV) like V95%, V100%, V110%, D98%, D50%, D2% and total number of MUs were compared. Normal Tissue Integral Dose (NTID) and dose to a shell structure PHY2.5 and PHY5.0 were analyzed.

RESULTS

Comparable dose coverage to PTV was observed for all the energies and arcs. CI for DA6MV (1.095) was better than SA6MV (1.127), SA10MV (1.116) and SA15MV (1.116). Evaluated parameters showed significant reduction in OAR doses. Mean bladder dose for DA6MV (41.90 Gy) was better than SA6MV (42.48 Gy), SA10MV (42.08 Gy) and SA15MV (41.93 Gy). Similarly, p-value for the mean rectal dose calculated was 0.001 (SA6 vs 15), 0.013 (DA6 vs 10) and 0.003 (DA6 vs 15) and subsequently favoured DA6MV. Difference in NTID was very small.

CONCLUSIONS

The study showed no greater advantage of higher energy, and DA VMAT plan with 6 MV photon energy was a good choice of treatment for carcinoma cervix as it delivered a highly homogeneous and conformal plan with superior target coverage and better OAR sparing.

Global strategies for the treatment of early-stage and advanced cervical cancer

PURPOSE OF REVIEW

Recent peer-reviewed publications on the treatment of early, locally advanced and advanced cervical cancer patients are reviewed to gain insight into the main research done in the field.

RECENT FINDINGS

In early-stage patients where cure is offered to most patients, research focuses on more conservative or less morbid approaches to increase quality of life and reduce the treatment-related sexual dysfunction. No major advances have occurred for treating locally advanced disease since the introduction of concurrent chemoradiation, but efforts are directed to increase efficacy while reducing toxicity with the use of combination chemoradiation and modern radiation technologies. Molecular-targeted therapy and identification of targetable gene alterations as well as immunotherapy are actively pursued in patients with advanced disease.

SUMMARY

Although global statistics indicate a trend for decreased age-standardized incidence rates, social and economical factors impede the uptake of therapeutic advances achieved as many patients have no access even to basic resources for treating cancer. The adherence to quality indicators in delivery of optimized standard concurrent chemoradiation and adherence to guidelines in cervical cancer surgery must not be underestimated. Major efforts are needed in both the scientific and social aspects of cervical cancer treatment to reduce mortality.

Comparison of dosimetric parameters and acute toxicity of intensity-modulated and three-dimensional radiotherapy in patients with cervix carcinoma: A randomized prospective study

PURPOSE

The use of intensity-modulated radiotherapy (IMRT) to treat cervix carcinoma has increased, however prospective randomized trials are still lacking.

AIM

To compare the dosimetric parameters and associated acute toxicity in patients with cervix carcinoma treated with three-dimensional (3D) conformal radiotherapy and IMRT.

PATIENTS AND METHODS

Forty patients were randomized in two arms each consisting of 20 patients. Patients in both arms received concurrent chemoradiation (cisplatin 40mg/m(2) weekly; 50Gy/25 fractions). Patients were treated with 3D conformal radiotherapy in one arm and with IMRT in another arm. After external beam radiotherapy, all patients received brachytherapy (21Gy/3 fractions at weekly interval). For dosimetric comparison, both kinds of the plans were done for all the patients. All patients were assessed throughout and until 90 days after completion of treatment for acute gastrointestinal, genitourinary and hematologic toxicities.

RESULTS

Both plans achieved adequate planning target volume coverage, while mean conformity index was found significantly better in IMRT plans (P-value=0.001). D35 (dose to 35% volume) and D50 for bladder was reduced by 14.62 and 32.57% and for rectum by 23.82 and 43.68% in IMRT. For IMRT, V45 (volume receiving 45Gy) of bowel were found significantly lesser (P-value=0.0001), non-tumour integral dose was found significantly higher (P-value=0.0240) and V20 of bone marrow was found significantly reduced (P-value=0.019) in comparison to that in 3D conformal radiotherapy. Significant reduction of grade 2 or more (20 vs 45%; P-value=0.058) and grade≥3 (5 vs 15%, P-value=0.004) acute genitourinary toxicity and grade 2 or more (20 vs 45%, P-value=0.003) and grade 3 or more (5 vs. 20%, P-value=0.004) acute gastrointestinal toxicity while no significant difference for grade 2 and 3 or more haematological toxicity was noted in patients treated with IMRT compared to 3D conformal radiotherapy.

CONCLUSION

IMRT provide a good alternative for treatment of cervix carcinoma with lower acute gastrointestinal and acute genitourinary toxicity with similar target coverage compared to 3D conformal radiotherapy.