Recent Advances and Adaptive Strategies in Image Guidance for Cervical Cancer Radiotherapy

Current status and challenges in training the next generation of gynecologic cancer care providers in Asia

OBJECTIVE

Gynecologic oncology is undergoing rapid development with continuous advances in treatment strategies, surgical techniques, and clinical research. Training programs must keep pace by providing future specialists with the necessary surgical skills and a solid understanding of evolving practices. This study aimed to examine the current state of gynecologic oncology training in Asia and to identify key challenges and opportunities for improvement.

METHODS

A descriptive survey was conducted in October 2023 under the leadership of the Education Committee of the Asian Society of Gynecologic Oncology (ASGO). Key stakeholders involved in clinical training and policy-making from eight countries and regions (China, Hong Kong SAR, India, Japan, the Philippines, South Korea, Taiwan, and Thailand) responded to an online questionnaire assessing the structure and quality of their national training programs.

RESULTS

Six of the eight countries/regions have official gynecologic oncology societies. Training duration was three years or more in five regions and two years in the remaining three. Seven reported conducting formal assessments of surgical skills. While five programs offered adequate exposure to minimally invasive surgery, three noted limitations. Satisfaction with research opportunities and overall training quality also varied. The most frequently cited concern was the lack of standardized curricula.

CONCLUSION

This regional overview reveals notable differences in training approaches across Asia. Standardizing educational frameworks and expanding collaborative initiatives - such as virtual tumor boards, elective rotations, and skills-based workshops - may help address current gaps and strengthen gynecologic oncology training in the region.

Initial needle tracking with the first standalone combined infrared camera - CT system for brachytherapy-analysis of tracking accuracy and uncertainties

PURPOSE

A prototype infrared camera - cone-beam computed tomography (CBCT) system for tracking in brachytherapy has recently been developed. We evaluated for the first time the corresponding tracking accuracy and uncertainties, and implemented a tracking-based prediction of needles on CBCT scans.

METHODS

A marker tool rigidly attached to needles was 3D printed. The precision and accuracy of tool tracking was then evaluated for both static and dynamic scenarios. Euclidean distances between the tracked and CBCT-derived markers were assessed as well. To implement needle tracking, ground truth models of the tool attached to 200 mm and 160 mm needles were matched to the tracked positions in order to project the needles into CBCT scans. Deviations between projected and actual needle tips were measured. Finally, we put our results into perspective with simulations of the system's tracking uncertainties.

RESULTS

For the stationary scenario and dynamic movements, we achieved tool-tracking precision and accuracy of 0.04 ± 0.06 mm and 0.16 ± 0.18 mm, respectively. The tracked marker positions differed by 0.52 ± 0.18 mm from the positions determined via CBCT. In addition, the predicted needle tips in air deviated from the actual tip positions by only 1.62 ± 0.68 mm (200 mm needle) and 1.49 ± 0.62 mm (160 mm needle). The simulated tracking uncertainties resulted in tip variations of 1.58 ± 0.91 mm and 1.31 ± 0.69 mm for the 200 mm and 160 mm needles, respectively.

CONCLUSION

With the innovative system it was possible to achieve a high tracking and prediction accuracy of marker tool and needles. The system shows high potential for applicator tracking in brachytherapy.

A comparative analysis of toxicity and treatment outcomes of adaptive radiotherapy and intensity-modulated radiotherapy in cervical cancer

Adaptive radiotherapy (ART) provides greater benefits than intensity-modulated radiotherapy (IMRT) regarding dosimetric outcomes in patients with cervical cancer. To investigate the clinical benefits of ART, we have collected data from 115 cervical cancer patients who underwent radical radiotherapy at our institution. Fifty-nine patients received a single course of IMRT. Fifty-six patients underwent offline ART, defined as the reduction of the gross tumor volume (GTV) by at least 30% after 30 Gy of radiotherapy, followed by a modified treatment plan for the second-stage. After treatment, 53 patients of ART group achieved a partial response (PR) or completement response (CR), resulting in an objective response rate (ORR) of 94.6% for the ART group, compared to 93.2% for the IMRT group. Patients in both groups exhibited no significant differences in acute toxicities. However, the incidence of chronic constipation was significantly higher in the IMRT group compared to the ART group (p = 0.021). With a median follow-up time of 27 months, the ART group experienced a higher mortality (10/56) than the IMRT group (6/59). However, the difference between the two groups was not statistically significant. In summary, ART may be advantageous in reducing the incidence of chronic constipation among patients with locally advanced cervical cancer, and both clinical prognosis and near-term survival are satisfactory.

Diagnostic and Interventional Imaging in Various Diseases

Diagnostic and interventional imaging is a cornerstone in the management of cases in various medical and surgical domains, such as neonatology, neurology, neurosurgery, otorhinolaryngology, dentistry, gynecology and urology [...].

Adaptive Approach to Treating Cervical Cancer in a Patient With Dramatic Uterine Movement

Adaptive radiation therapy is a modern technological advancement that allows radiation treatments to be adjusted daily to account for changes in the patient's anatomy, such as bladder and rectal filling, as well as changes in the tumor volume and position. In this case report, we present a patient with locally advanced cervical cancer who received definitive radiation therapy of 4500 cGy in 25 fractions using the Varian's Ethos system. We observed substantial daily uterine movement, which required re-optimization of each treatment fraction. Without the daily plan adaptation, the treatment would have resulted in markedly suboptimal dose coverage to the tumor. This case report highlights the importance of adaptive radiotherapy in managing anatomical changes in cervical cancer treatment and improving outcomes.

The Impact of Dual and Triple Energy Window Scatter Correction on I-123 Postsurgical Thyroid SPECT/CT Imaging Using a Phantom with Small Sizes of Thyroid Remnants

I-123 is preferential over I-131 for diagnostic SPECT imaging after a thyroidectomy to determine the presence and size of residual thyroid tissue for radioiodine ablation. Scattering degrades the quality of I-123 SPECT images, primarily due to the penetration of high-energy photons into the main photopeak. The objective of this study was to quantitatively and qualitatively investigate the impact of two widely used window-based scatter correction techniques, the dual energy window (DEW) and triple energy window (TEW) techniques, in I-123 postsurgical SPECT/CT thyroid imaging using an anthropomorphic phantom with small sizes of remnants and anatomically correct surrounding structures. For this purpose, non-scatter-corrected, DEW and TEW scatter-corrected SPECT/CT acquisitions were performed for 0.5-10 mL remnants within a phantom, with 0.5-12.6 MBq administered activities within the remnants, and without and with background-to-remnant activity ratios of 5% and 10%. The decrease in photons, the noise and non-uniformity in the background region due to scatter correction were measured, as well as the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) from small remnants. The images were also visually evaluated by two experienced nuclear medicine physicians. Scatter correction decreased photons to a higher extent in larger regions than smaller regions. Larger remnants yielded higher SNR and CNR values, particularly at lower background activities. It was found from the quantitative analysis and the qualitative evaluation that TEW scatter correction performed better than DEW scatter correction, particularly at higher background activities, while no significant differences were reported at lower background activities. Scatter correction should be applied in I-123 postsurgical SPECT/CT imaging to improve the image contrast and detectability of small remnants within the background.