Effect of Field Size and Length of Plantar Spur on Treatment Outcome in Radiation Therapy of Plantar Fasciitis: The Bigger the Better?

Radiotherapy CT-based contouring atlas for non-malignant skeletal and soft tissue disorders: a practical proposal from Spanish experience

OBJECTIVE

Interest in low-dose radiotherapy (LD-RT) for the symptomatic treatment of nonmalignant conditions, including inflammatory and degenerative disorders of the joints and para-articular soft tissues, has increased substantially in recent years. In the present document, we provide a CT-based contouring atlas to help identify and delineate the most common osteoarticular regions susceptible to LD-RT.

METHODS

The clinical efficacy of LD-RT is supported by a large body of evidence. However, there is no consensus on the parameters for contouring the planning target volume (PTV). Moreover, 3D simulation and planning should be the standard of care even for nonmalignant disorders. For this reason, the present guidelines were prepared to help guide PTV contouring based on CT images, with the same quality criteria for patient immobilization, treatment simulation, planning and delivery as those routinely applied for cancer radiotherapy.

RESULTS

PTV for radiotherapy requires precise identification of the target areas based on CT and other imaging techniques. Using a series of cases treated at our institution, we have defined the PTVs for each location on the simulation CT to establish the relationship between the image and the anatomical structures to be treated. We also specify the immobilization systems used to ensure treatment accuracy and reproducibility.

CONCLUSIONS

This comprehensive atlas based on CT images may be of value to radiation oncologists who wish to use LD-RT for the symptomatic treatment of degenerative or inflammatory osteoarticular diseases.

ADVANCES IN KNOWLEDGE

The recommendations and contouring atlas described in this article provide an eminently practical tool for LD-RT in non-malignant conditions, based on the same quality criteria recommended for all modern radiotherapy treatments in Spain.

Long-term effect and prognostic factors of a low-dose radiotherapy of painful plantar calcaneal spurs : A retrospective unicenter study

PURPOSE

To estimate the long-term effect of low-dose radiotherapy of painful plantar calcaneal spurs, and to verify possible prognostic factors.

PATIENTS AND METHODS

In this retrospective unicenter study, electronic patient files of patients with painful plantar calcaneal spurs treated with low-dose radiotherapy between July 2009 and February 2020 were reviewed. The low-dose radiotherapy consisted of a total dose of 3.0 Gy given with a fraction dose of 0.5 Gy three times a week. The pain reduction was estimated using a patient questionnaire with a visual analogue scale. Kaplan-Meier statistics and Cox regression analysis were used for the statistical analysis.

RESULTS

Altogether, 864 heels of 666 patients were reviewed. The probability of an insufficient pain control 10 years after low-dose radiotherapy was 45.9% (95% confidence interval 39.4-52.4%) in the subset of patients with a minimum follow-up of 3 months (582 heels of 467 patients). Patients with an unsatisfactory pain reduction 3 months after low-dose radiotherapy were offered a re-irradiation. Forty percent of the patients who received a re-irradiation developed good pain reduction. Occurrence of an initial aggravation of pain during or within 3 months after low-dose radiotherapy (p = 0.005), and treatment of bilateral painful plantar calcaneal spurs (p = 0.008) were identified as significant unfavorable prognostic factors on univariate analysis. On multivariate analysis, the initial aggravation of pain remained as independent significant prognostic factor (p = 0.01). No clear radiation toxicity was observed.

CONCLUSIONS

Low-dose radiotherapy is a safe and effective treatment option for patients with painful plantar calcaneal spurs. An initial aggravation of pain during or within 3 months after radiotherapy was identified as unfavorable prognostic factor for the treatment outcome. Re-irradiation of patients with an unsatisfactory pain reduction after low-dose radiotherapy is effective and should be offered to patients.

The plantar calcaneal spur: a review of anatomy, histology, etiology and key associations

The plantar calcaneal spur (PCS) is a bony outgrowth from the calcaneal tuberosity and has been studied using various methods including cadavers, radiography, histology and surgery. However, there are currently a number of discrepancies in the literature regarding the anatomical relations, histological descriptions and clinical associations of PCS. Historically, authors have described the intrinsic muscles of the foot and/or the plantar fascia as attaching to the PCS. In this article we review the relationship between the PCS and surrounding soft tissues as well as examining the histology of the PCS. We identify a number of key associations with PCS, including age, weight, gender, arthritides, plantar fasciitis and foot position; these factors may function as risk factors in PCS formation. The etiology of these spurs is a contentious issue and it has been explained through a number of theories including the degenerative, inflammatory, traction, repetitive trauma, bone-formers and vertical compression theories. We review these and finish by looking clinically at the evidence that PCS causes heel pain.