Guanghui Cheng

Multi-atlas-based segmentation of the parotid glands of MR images in patients following head-and-neck cancer radiotherapy

Xerostomia (dry mouth), resulting from radiation damage to the parotid glands, is one of the most common and distressing side effects of head-and-neck cancer radiotherapy. Recent MRI studies have demonstrated that the volume reduction of parotid glands is an important indicator for radiation damage and xerostomia. In the clinic, parotid-volume evaluation is exclusively based on physicians’ manual contours. However, manual contouring is time-consuming and prone to inter-observer and intra-observer variability. Here, we report a fully automated multi-atlas-based registration method for parotid-gland delineation in 3D head-and-neck MR images. The multi-atlas segmentation utilizes a hybrid deformable image registration to map the target subject to multiple patients’ images, applies the transformation to the corresponding segmented parotid glands, and subsequently uses the multiple patient-specific pairs (head-and-neck MR image and transformed parotid-gland mask) to train support vector machine (SVM) to reach consensus to segment the parotid gland of the target subject. This segmentation algorithm was tested with head-and-neck MRIs of 5 patients following radiotherapy for the nasopharyngeal cancer. The average parotid-gland volume overlapped 85% between the automatic segmentations and the physicians’ manual contours. In conclusion, we have demonstrated the feasibility of an automatic multi-atlas based segmentation algorithm to segment parotid glands in head-and-neck MR images.

Successful salvage treatment of refractory recurrence of maxillary sinus carcinoma using image-guided high-dose-rate interstitial brachytherapy

This case report illustrates a treatment effect of image-guided high-dose-rate (HDR) interstitial brachytherapy for refractory recurrence of maxillary sinus carcinoma. A 61-year-old male was previously admitted to another hospital and received surgery because of left maxillary sinus squamous cell carcinoma (SCC) 6 years ago. Tumor regrowth was noted 2 years after the initial radical surgery. The patient accepted local excision again for the recurrence, followed by external beam radiotherapy. Despite salvage treatment with surgery and external irradiation, the lesion expanded as 4.8 × 4.4 × 4.0 cm3. Because the patient refused palliative resection, we recommended technique of image-guided HDR interstitial brachytherapy. The total doses of 42 Gy in 12 fractions were delivered to the whole recurrent tumor. Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy, guided with ultrasound. The refractory tumor in the patient healed uneventfully after HDR interstitial brachytherapy without recurrence during 8 months of follow-up. This case is remarkable because the patient experienced complete remission by a safe and practicable method with image-guided HDR interstitial brachytherapy.

Image-guided high-dose-rate intracavitary brachytherapy technique for nasal keloid – a case report

The aim of this study is to report an uncommon case of nasal keloid treated with adaptive image-guided high-dose-rate (HDR) intracavitary brachytherapy. A 34-year-old female presented with nasal keloid after facial trauma was treated with scar resection and HDR intracavitary brachytherapy with a customized eccentric applicator. The total dose was 21 Gy in 6 fractions. During 3 years of follow-up, there was no evidence of recurrence at the local site, and no complications. In conclusion, HDR intracavitary brachytherapy is an effective way to prevent the recurrence of nasal keloids post-surgery.

Image-guided high-dose-rate interstitial brachytherapy technique for locally recurrent rectal cancer in perineum

Purpose The aim of the report was the evaluation of application with image-guided high-dose-rate (HDR) interstitial brachytherapy in patients undergoing conventional chemo-radiotherapy for perineal locally recurrent rectal cancer (LRRC). Material and methods 75-year-old female patient presented with LRRC three years after total mesorectal excision (TME) surgery for rectal cancer with tubular adenocarcinoma (stage IIIB). Despite conventional chemotherapy and external beam radiotherapy, the re-recurrent lesion expanded as 4.5 × 5.5 cm2 located in perineum with skin invasion. The loco-regional recurrent tumor was treated with HDR interstitial brachytherapy under ultrasound guidance and magnetic resonance imaging-based treatment planning. The brachytherapy dose was 50 Gy in 10 fractions of 5 Gy each for 5 weeks. Results Removal of the perineal LRRC was securely achieved by image-guided HDR interstitial brachytherapy technique. The refractory tumor healed uneventfully after interstitial brachytherapy without recurrence during 26 months of follow-up. The patient had good quality of life without serious complications of treatment. Conclusions Image-guided HDR interstitial brachytherapy in selected patient with LRRC in perineum is a proven, effective, and safe treatment method with relatively long-term outcome.

Image-guided high-dose-rate interstitial brachytherapy - a valuable salvage treatment approach for loco-regional recurrence of papillary thyroid cancer.

Purpose To report the treatment effect of image-guided high-dose-rate (HDR) interstitial brachytherapy for refractory recurrence of papillary thyroid cancer (PTC). Case report This 66-year-old female presented with recurrence 5 years after thyroidectomy for PTC. Despite external irradiation and radioactive 131I, the lesion expanded as 3.7 × 3.0 × 2.3 cm3 and 2.0 × 1.5 × 1.5 cm3. The locoregional recurrent tumor was treated with image-guided HDR interstitial brachytherapy. The total dose of 30 Gy in 6 fractions were delivered on the whole recurrent tumor. Results Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy guided with ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) scanning. The refractory tumor in the patients healed uneventfully after HDR interstitial brachytherapy without recurrence during the 14 months of follow-up. Conclusions The image-guided HDR interstitial brachytherapy may be a valuable salvage treatment approach for refractory recurrence of PTC.

Interstitial brachytherapy technique for chest wall refractory recurrence of breast cancer

Purpose To report the treatment effect of interstitial brachytherapy for chest wall locoregional recurrence of breast cancer. Material and methods This 44-year-old female presented with chest wall recurrence seven years after modified radical mastectomy for stage II breast cancer. Despite external beam radiation and chemotherapy, the lesion expanded as 5.3 × 5.1 × 3.0 cm3, and 8.0 × 5.1 × 4.0 cm3. The locoregional recurrent tumor was treated with interstitial brachytherapy under ultrasound guidance. The brachytherapy dose was 30 Gy in 6 fractions of 5 Gy each. Results Removal of the recurrent tumor was securely achieved by interstitial brachytherapy guided with ultrasound scanning. The refractory tumor in patient healed uneventfully after interstitial brachytherapy without recurrence during the 7 months of follow-up. Conclusions The ultrasound-guided interstitial brachytherapy may be effective for refractory recurrence of breast cancer.

A case report of ultrasound-guided interstitial brachytherapy for abdominal wall metastases of ovarian cancer

Purpose To report the treatment effect of interstitial brachytherapy for abdominal wall metastases of ovarian cancer. Material and methods The patient is a 44-year-old female with a diagnosis of stage IA ovarian cancer. After surgery and two cycles of chemotherapy with paclitaxel and carboplatin, the patient noticed dull pain in the lower abdomen and found a mass located in the subcutaneous tissue, below the operative incision. A diagnostic biopsy showed abdominal wall metastases. After external radiotherapy with a dose of 39.6 Gy in 22 fractions, the residual tumor was treated with interstitial brachytherapy under ultrasound guidance. The brachytherapy dose was 18 Gy in 6 fractions of 3 Gy each. Results After 3 weeks of brachytherapy, the tumor had disappeared completely. Interstitial brachytherapy was feasible. Conclusions Interstitial brachytherapy may be a proposed treatment strategy for inoperable superficial metastases, especially for low radiosensitivity cancer.

A of ultrasound-guided interstitial brachytherapy for abdominal wall metastases of ovarian cancer

Purpose To report the treatment effect of interstitial brachytherapy for abdominal wall metastases of ovarian cancer. Material and methods The patient is a 44-year-old female with a diagnosis of stage IA ovarian cancer. After surgery and two cycles of chemotherapy with paclitaxel and carboplatin, the patient noticed dull pain in the lower abdomen and found a mass located in the subcutaneous tissue, below the operative incision. A diagnostic biopsy showed abdominal wall metastases. After external radiotherapy with a dose of 39.6 Gy in 22 fractions, the residual tumor was treated with interstitial brachytherapy under ultrasound guidance. The brachytherapy dose was 18 Gy in 6 fractions of 3 Gy each. Results After 3 weeks of brachytherapy, the tumor had disappeared completely. Interstitial brachytherapy was feasible. Conclusions Interstitial brachytherapy may be a proposed treatment strategy for inoperable superficial metastases, especially for low radiosensitivity cancer.

Utrecht Interstitial Applicator Shifts and DVH Parameter Changes in 3D CT-based HDR Brachytherapy of Cervical Cancer

BACKGROUND For brachytherapy of cervical cancer, applicator shifts can not be avoided. The present investigation concerned Utrecht interstitial applicator shifts and their effects on organ movement and DVH parameters during 3D CT-based HDR brachytherapy of cervical cancer. MATERIALS AND METHODS After the applicator being implanted, CT imaging was achieved for oncologist contouring CTVhr, CTVir, and OAR, including bladder, rectum, sigmoid colon and small intestines. After the treatment, CT imaging was repeated to determine applicator shifts and OARs movements. Two CT images were matched by pelvic structures. In both imaging results, we defined the tandem by the tip and the base as the marker point, and evaluated applicator shift, including X, Y and Z. Based on the repeated CT imaging, oncologist contoured the target volume and OARs again. We combined the treatment plan with the repeated CT imaging and evaluated the change range for the doses of CTVhr D90, D2cc of OARs. RESULTS The average applicator shift was -0.16 mm to 0.10 mm for X, 1.49 mm to 2.14 mm for Y, and 1.9 mm to 2.3 mm for Z. The change of average physical doses and EQD2 values in Gyα/β range for CTVhr D90 decreased by 2.55 % and 3.5 %, bladder D2cc decreased by 5.94 % and 8.77 %, rectum D2cc decreased by 2.94 % and 4 %, sigmoid colon D2cc decreased by 3.38 % and 3.72 %, and small intestines D2cc increased by 3.72 % and 10.94 %. CONCLUSIONS Applicator shifts and DVH parameter changes induced the total dose inaccurately and could not be ignored. The doses of target volume and OARs varied inevitably.