Adaptive 3D image-guided brachytherapy: a strong argument in the debate on systematic radical hysterectomy for locally advanced cervical cancer

Pulsed-dose rate image-guided adaptive brachytherapy in cervical cancer: Dose-volume effect relationships for the rectum and bladder

PURPOSE

To establish dose-volume effect correlations for late bladder and rectum side effects in patients treated for locally advanced cervical cancer with concomitant chemoradiation followed by pulsed-dose rate image-guided adaptive brachytherapy.

MATERIAL AND METHODS

The dosimetric data, converted in 2 Gy equivalent, from 217 patients were confronted to late morbidity defined as any event lasting or occurring 90 days after treatment initiation. Toxicity was assessed using the CTC-AE 3.0. Probit analyses and Log rank tests were performed to assess relationships.

RESULTS

One hundred and sixty-one urinary and 58 rectal events were reported, affecting 98 (45.1%) and 51 (23.5%) patients, respectively. Cumulative incidences for grade 2-4 bladder and rectal morbidity were 24.3% and 9.6% at 3 years, respectively. Significant relationships were observed between grade 2-4 and 3-4 events and D0.1cm(3) and D2 cm(3) for the bladder and between grade 1-4 and 2-4 event probability and rectal D2 cm(3). The effective doses for 10% grade 2-4 morbidity were 65.3 Gy (59.8-81.3), and 55.4 Gy (15.7-63.6), respectively, for the rectum and bladder. Without considering urinary and rectal incontinence, for which the pertinence of correlating them with D2 cm(3) is questionable, ED10 were 68.5 Gy (62.9-110.6) and 65.5 Gy (51.4-71.6 Gy). When sorting patients according to D2 cm(3) levels, patients with high D2 cm(3) had significantly lower morbidity free survival rates for grade 1-4 and 2-4 urinary and rectal morbidity.

CONCLUSION

Significant dose-volume effect relationships were demonstrated between the modern dosimetric parameters and the occurrence of late rectal and urinary morbidity in patients treated with pulsed-dose-rate brachytherapy. Further studies are required to refine these relationships according to clinical cofactors, such as comorbidities.

Image-guided radiotherapy and -brachytherapy for cervical cancer

Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer.

The role of F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) in the screening of cervical cancer: a literature review

F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) has of late gained prominence in the investigation of cervical cancer since it gives a better clarity on imaging modalities for the status of the lymph node and distant metastasis. The current review is an appraisal of the recent updates on the role of FDG-PET/CT in the screening of cervical cancer as evidenced by publications till date. 985 studies were obtained in the initial search on cervical cancer and publications selected based on inclusion and exclusion criteria. In the final selection, 14 were selected and coded as the most appropriate for the present review. Valuable studies on (FDG) PET/CT have been identified. These studies point to the fact that recent advanced protocols like PET/CT supported by therapeutic innovations ensure better cancer care and survival chances in cervical cancer patients.

An integrated teaching method of gross anatomy and computed tomography radiology

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench-side (OsiriX on iPod touch or iPad), which enabled "pixel-to-tissue" direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses.

[Pulsed-dose rate brachytherapy in cervical cancers: why, how?]

The end of the production of 192 iridium wires terminates low dose rate brachytherapy and requires to move towards pulsed-dose rate or high-dose rate brachytherapy. In the case of gynecological cancers, technical alternatives exist, and many teams have already taken the step of pulsed-dose rate for scientific reasons. Using a projector source is indeed a prerequisite for 3D brachytherapy, which gradually installs as a standard treatment in the treatment of cervical cancers. For other centers, this change implies beyond investments in equipment and training, organizational consequences to ensure quality.

A new laparoscopic method of bowel radio-protection before pelvic chemoradiation of locally advanced cervix cancers

BACKGROUND

Chemoradiation therapy (CRT) has become the mainstay of locally advanced cervical carcinomas (LACC). However, the price to pay is a significant rate of both early and late colo-rectal toxicities, which may impact on survivors' quality of life. To reduce the incidence of such complications, we suggest a simple technique of pelvic radioprotection.

MATERIALS AND METHODS

An omental flap is created which is placed to fill the Douglas pouch to both increase the space between rectum and uterine cervix and prevent small bowel to fall in and to be exposed to radiation. In addition, a long sigmoid loop is retracted and fixed in the left paracolic gutter to prevent its irradiation as well.

RESULTS

From May 2011 to May 2012, 51 successive LACC patients were offered this procedure in addition of a laparoscopic staging. All but 2 with too small an omentum benefitted from omentoplasty, while sigmoidopexy was performed in all but one patient with a long and free sigmoid loop. No immediate adverse effect was observed. The volume of retro-uterine omental flap averaged 7.17 ± 3.79 cm(3). Sequential measurements of the utero-rectal space throughout CRT duration showed a real and durable increase in the distance between these organs, resulting in a drop in the dose of irradiation to recto-sigmoid. With 10 ± 4.5-month median follow-up, we did not observe any rectal or small bowel early or late adverse effects of CRT.

CONCLUSIONS

Although this series is preliminary, this simple procedure, feasible by laparoscopy (or laparotomy), seems effective to prevent recto-sigmoid as well as small bowel from radio-induced complications due to pelvic CRT.

Locally advanced cervical cancer in renal transplant patients: a dilemma between control and toxicity

PURPOSE

Treatment of locally advanced cervical cancer in patients with a renal graft requires precautions. The graft is usually in a pelvic position, close to the clinical target volume (CTV). Preserving the graft while ensuring local control is a challenge we have faced in two occasions. We report our experience.

METHODS AND MATERIALS

We report the cases of 2 patients treated at our institution with a modified workup and therapeutic approach compared with our standard approach. The clinical and technical aspects of both treatments were systematically reviewed and contrasted with reports previously cited in the literature.

RESULTS

The first patient received external beam conformal radiotherapy (total dose: 30 Gy in the pelvis) followed by two sessions of MRI-guided brachytherapy (2 × 15 Gy to 90% of the intermediate risk CTV). The second one received pelvic intensity-modulated radiation therapy (total dose: 45 Gy) followed by MRI-guided brachytherapy delivering 15 Gy to 90% of the intermediate risk CTV. Both patients had a complete response and were still in remission more than 2 years after treatment while retaining their graft. No severe late toxicity was reported.

CONCLUSIONS

External beam radiotherapy followed by brachytherapy is feasible in locally advanced cervical cancer, despite the presence of a kidney graft near the targets. Image-guided adaptive brachytherapy allowed an accurate evaluation of the dose distribution, reaching the recommended treatment thresholds with optimal protection of the graft.